text: In December 1925, the BBC's experimental transmitting station, 5XX, in Daventry, Northamptonshire, made radio's first stereo broadcast—a concert from Manchester, conducted by Sir Hamilton Harty—with 5XX broadcasting the right channel nationally by long wave and local BBC stations broadcasting the left channel by medium wave. The BBC repeated the experiment in 1926, using 2LO in London and 5XX at Daventry. Following experimental FM stereo transmissions in the London area in 1958 and regular Saturday morning demonstration transmissions using TV sound and medium wave (AM) radio to provide the two channels, the first regular BBC transmissions using an FM stereo signal began on the BBC's Third Programme network on August 28, 1962.

text: In December 1925, the

entity_name: BBC

text: BBC

text: 's experimental transmitting station, 5XX, in

entity_name: Daventry

text: Daventry, Northamptonshire

text: , made radio's first stereo broadcast—a concert from

entity_name: Manchester

text: Manchester

text: , conducted by

entity_name: Hamilton Harty

text: Sir Hamilton Harty

text: —with 5XX broadcasting the right channel nationally by

entity_name: Longwave

text: long wave

text: and local BBC stations broadcasting the left channel by

entity_name: Medium wave

text: medium wave

text: . The BBC repeated the experiment in 1926, using 2LO in London and 5XX at Daventry. Following experimental FM stereo transmissions in the London area in 1958 and regular Saturday morning demonstration transmissions using TV sound and medium wave (AM) radio to provide the two channels, the first regular BBC transmissions using an FM stereo signal began on the BBC's

entity_name: BBC Third Programme

text: Third Programme

text: network on August 28, 1962.

text: Following an experiment by the former UK broadcast regulator Radio Authority, since 2005 some 200 such stations have been licensed by broadcasting regulator Ofcom. Most community radio stations in the UK are on FM, typically at a power of 25 watts. FM community radio stations include Preston FM, Penistone FM and West Hull FM founded as WHCR in 2007 and based in Kingston upon Hull, East Riding of Yorkshire. A few community radio station also operate on AM (medium wave), particularly in rural areas, and some community radio stations operate online, like Windmill Broadcasting, the UK's only radio station broadcasting from a Windmill, in the Broad Eye Windmill, Stafford.

text: Following an experiment by the former UK broadcast regulator Radio Authority, since 2005 some 200 such stations have been licensed by broadcasting regulator

entity_name: Ofcom

text: Ofcom

text: . Most community radio stations in the

entity_name: United Kingdom

text: UK

text: are on

entity_name: FM broadcasting

text: FM

text: , typically at a power of 25 watts. FM community radio stations include

entity_name: Preston FM

text: Preston FM

entity_name: Penistone FM

text: Penistone FM

text: and

entity_name: 106.9 West Hull FM

text: West Hull FM

text: founded as WHCR in 2007 and based in

entity_name: Kingston upon Hull

text: Kingston upon Hull

text: , East Riding of Yorkshire. A few community radio station also operate on AM (

text: medium wave

text: ), particularly in rural areas, and some community radio stations operate online, like

entity_name: Windmill Broadcasting

text: Windmill Broadcasting

text: , the UK's only radio station broadcasting from a

entity_name: Windmill

text: Windmill

text: , in the

entity_name: Broad Eye Windmill

text: Broad Eye Windmill

entity_name: Stafford

text: Stafford

method: UNH-qee

text: WOAP was founded as an AM/FM combo station by the local Argus-Press newspaper.  The call letters stand for Owosso Argus-Press.  As the AM station was, and still is, a daytime-only station, the FM station was intended to provide full-time service to the Owosso area. But at that time, there were very few FM radios so WOAP-FM went silent by 1953.  A decade later, there were enough FM radios in circulation to allow WOAP-FM to return to the air on December 2, 1965.

text: WOAP was founded as an AM/FM combo station by the local Argus-Press newspaper.  The call letters stand for Owosso

entity_name: Argus-Press

text: Argus-Press

text: .  As the AM station was, and still is, a daytime-only station, the FM station was intended to provide full-time service to the Owosso area. But at that time, there were very few FM radios so WOAP-FM went silent by 1953.  A decade later, there were enough FM radios in circulation to allow WOAP-FM to return to the air on December 2, 1965.

method: ICT-DRMMTKS

text: The weak absorption of radio waves by the medium through which it passes is what enables radar sets to detect objects at relatively long ranges—ranges at which other electromagnetic wavelengths, such as visible light, infrared light, and ultraviolet light, are too strongly attenuated. Such weather phenomena as fog, clouds, rain, falling snow, and sleet that block visible light are usually transparent to radio waves. Certain radio frequencies that are absorbed or scattered by water vapour, raindrops, or atmospheric gases (especially oxygen) are avoided in designing radars, except when their detection is intended.

text: The weak absorption of radio waves by the medium through which it passes is what enables radar sets to detect objects at relatively long ranges—ranges at which other electromagnetic wavelengths, such as

entity_name: Light

text: visible light

entity_name: Infrared

text: infrared light

text: , and

entity_name: Ultraviolet

text: ultraviolet light

text: , are too strongly attenuated. Such weather phenomena as fog, clouds, rain, falling snow, and sleet that block visible light are usually transparent to radio waves. Certain radio frequencies that are absorbed or scattered by water vapour, raindrops, or atmospheric gases (especially oxygen) are avoided in designing radars, except when their detection is intended.

text: A parabolic (or paraboloid or paraboloidal) reflector (or dish or mirror) is a reflective surface used to collect and project energy such as light, sound, or radio waves. Its shape is part of a circular paraboloid, that is, the surface generated by a parabola revolving around its axis. The parabolic reflector transforms an incoming plane wave traveling along the axis into a spherical wave converging toward the focus. Conversely, a spherical wave generated by a point source placed in the focus is reflected into a plane wave propagating as a collimated beam along the axis.

text: A parabolic (or paraboloid or paraboloidal) reflector (or dish or mirror) is a

entity_name: Mirror

text: reflective

text: surface used to collect and project

entity_name: Energy

text: energy

text: such as

text: light

entity_name: Sound

text: sound

text: , or

entity_name: Radio wave

text: radio wave

text: s. Its shape is part of a

entity_name: Paraboloid

entity_section: Properties

text: circular paraboloid

text: , that is, the surface generated by a

entity_name: Parabola

text: parabola

text: revolving around its axis. The parabolic reflector transforms an incoming

entity_name: Plane wave

text: plane wave

text: traveling along the axis into a

entity_name: Wave equation

entity_section: Spherical waves

text: spherical wave

text: converging toward the focus. Conversely, a spherical wave generated by a

entity_name: Point source

text: point source

text: placed in the focus is reflected into a plane wave propagating as a collimated beam along the axis.

text: Radio Televizioni Shqiptar (RTSH) is the public radio and TV broadcaster of Albania, founded by King Zog in 1938. RTSH runs three analogue television stations as TVSH Televizioni Shqiptar, four digital thematic stations as RTSH, and three radio stations using the name Radio Tirana. In addition, 4 regional radio stations serve in the four extremities of Albania.The international service broadcasts radio programmes in Albanian and seven other languages via medium wave (AM) and short wave (SW). The international service has used the theme from the song "Keputa një gjethe dafine" as its signature tune. The international television service via satellite was launched since 1993 and aims at Albanian communities in Kosovo, Serbia, Macedonia, Montenegro and northern Greece, plus the Albanian diaspora in the rest of Europe. RTSH has a past of being heavily influenced by the ruling party in its reporting, whether that party be left or right wing.

text: Radio Televizioni Shqiptar (RTSH) is the public radio and TV broadcaster of Albania, founded by

entity_name: Zog I of Albania

text: King Zog

text: in 1938. RTSH runs three analogue television stations as TVSH Televizioni Shqiptar, four digital thematic stations as RTSH, and three radio stations using the name Radio Tirana. In addition, 4 regional radio stations serve in the four extremities of Albania.The international service broadcasts radio programmes in Albanian and seven other languages via

text: medium wave

text: (AM) and

entity_name: Shortwave radio

text: short wave

text: (SW). The international service has used the theme from the song "Keputa një gjethe dafine" as its

entity_name: Signature song

text: signature tune

text: . The international television service

entity_name: Satellite

text: via satellite

text: was launched since 1993 and aims at

entity_name: Albanian language

text: Albanian

text: communities in Kosovo, Serbia, Macedonia, Montenegro and northern Greece, plus the Albanian

entity_name: Diaspora

text: diaspora

text: in the rest of Europe. RTSH has a past of being heavily influenced by the ruling party in its reporting, whether that party be left or right wing.

text: The transfer of energy between the wind blowing over the surface of an ocean and the ocean's upper layer is an important element in wave dynamics.  The spectral wave transport equation is used to describe the change in wave spectrum over changing topography.  It simulates wave generation, wave movement (propagation within a fluid), wave shoaling, refraction, energy transfer between waves, and wave dissipation.  Since surface winds are the primary forcing mechanism in the spectral wave transport equation, ocean wave models use information produced by numerical weather prediction models as inputs to determine how much energy is transferred from the atmosphere into the layer at the surface of the ocean. Along with dissipation of energy through whitecaps and resonance between waves, surface winds from numerical weather models allow for more accurate predictions of the state of the sea surface.<ref>{{cite journal|last=Bender|first=Leslie C.|title=Modification of the Physics and Numerics in a Third-Generation Ocean Wave Model|journal=Journal of Atmospheric and Oceanic Technology|date=January 1996|volume=13|issue=3|pages=726 |doi=10.1175/1520-0426(1996)013

text: The transfer of energy between the wind blowing over the surface of an ocean and the ocean's upper layer is an important element in wave dynamics.  The

text: spectral wave transport equation

text: is used to describe the change in wave spectrum over changing topography.  It simulates wave generation, wave movement (propagation within a fluid),

entity_name: Wave shoaling

text: wave shoaling

entity_name: Refraction

text: refraction

text: , energy transfer between waves, and wave dissipation.  Since surface winds are the primary forcing mechanism in the spectral wave transport equation, ocean wave models use information produced by numerical weather prediction models as inputs to determine how much energy is transferred from the atmosphere into the layer at the surface of the ocean. Along with dissipation of energy through

entity_name: Wind wave

text: whitecaps

text: and

entity_name: Resonance

text: resonance

text: between waves, surface winds from numerical weather models allow for more accurate predictions of the state of the sea surface.<ref>{{cite journal|last=Bender|first=Leslie C.|title=Modification of the Physics and Numerics in a Third-Generation Ocean Wave Model|journal=

entity_name: Journal of Atmospheric and Oceanic Technology

text: Journal of Atmospheric and Oceanic Technology

text: |date=January 1996|volume=13|issue=3|pages=726 |doi=10.1175/1520-0426(1996)013

text: In physics, a surface wave is a mechanical wave that propagates along the interface between differing media, usually as a gravity wave between two fluids with different densities.  A surface wave can also be an elastic (or a seismic) wave, such as with a Rayleigh or Love wave. It can also be an electromagnetic wave guided by a refractive index gradient, or along an interface between two media having different dielectric constants. In radio transmission, a ground wave is a surface wave that propagates close to the surface of the Earth.

text: In

entity_name: Physics

text: physics

text: , a surface wave is a

entity_name: Mechanical wave

text: mechanical wave

text: that propagates along the

entity_name: Interface (matter)

text: interface

text: between differing media, usually as a

entity_name: Gravity wave

text: gravity wave

text: between two

entity_name: Fluid

text: fluid

text: s with different densities.  A surface wave can also be an elastic (or a

entity_name: Seismic wave

text: seismic

text: ) wave, such as with a

entity_name: Rayleigh wave

text: Rayleigh

text: or

entity_name: Love wave

text: Love

text: wave. It can also be an

entity_name: Electromagnetic radiation

text: electromagnetic wave

text: guided by a

entity_name: Refractive index

text: refractive index

entity_name: Gradient

text: gradient

text: , or along an interface between two media having different dielectric constants. In

entity_name: Radio

text: radio

entity_name: Transmission (telecommunications)

text: transmission

text: , a ground wave is a surface wave that propagates close to the surface of the

entity_name: Earth

text: Earth

text: The nation's principal media outlet is its state-sponsored combined television and radio service, Radiodiffusion-Télévision Burkina (RTB). RTB broadcasts on two medium-wave (AM) and several FM frequencies. Besides RTB, there are privately owned sports, cultural, music, and religious FM radio stations. RTB maintains a worldwide short-wave news broadcast (Radio Nationale Burkina) in the French language from the capital at Ouagadougou using a 100 kW transmitter on 4.815 and 5.030 MHz.

text: The nation's principal media outlet is its state-sponsored combined television and radio service, Radiodiffusion-Télévision Burkina (RTB). RTB broadcasts on two

text: medium-wave

entity_name: Amplitude modulation

text: AM

text: ) and several

entity_name: Frequency modulation

text: FM

text: frequencies. Besides RTB, there are privately owned sports, cultural, music, and religious FM radio stations. RTB maintains a worldwide short-wave news broadcast (Radio Nationale Burkina) in the French language from the capital at Ouagadougou using a 100 kW transmitter on 4.815 and 5.030 MHz.

text: The absence of a material medium in vacuum may also constitute a transmission medium for electromagnetic waves such as light and radio waves.

text: The absence of a material medium in

entity_name: Vacuum

text: vacuum

text: may also constitute a transmission medium for

text: electromagnetic wave

text: s such as

text: light

text: and

text: radio wave

text: s.

text: Frequency modulation is widely used for FM radio broadcasting.  It is also used in telemetry, radar, seismic prospecting, and monitoring newborns for seizures via EEG,  two-way radio systems, music synthesis, magnetic tape-recording systems and some video-transmission systems.  In radio transmission, an advantage of frequency modulation is that it has a larger signal-to-noise ratio and therefore rejects radio frequency interference better than an equal power amplitude modulation (AM) signal.  For this reason, most music is broadcast over FM radio.

text: Frequency modulation is widely used for

text: FM radio

entity_name: Broadcasting

text: broadcasting

text: .  It is also used in

entity_name: Telemetry

text: telemetry

entity_name: Radar

text: radar

text: , seismic prospecting, and monitoring

entity_name: Infant

text: newborn

text: s for seizures via

entity_name: Electroencephalography

text: EEG

entity_name: Two-way radio

text: two-way radio

text: systems,

entity_name: Synthesizer

text: music synthesis

text: , magnetic tape-recording systems and some video-transmission systems.  In radio transmission, an advantage of frequency modulation is that it has a larger

entity_name: Signal-to-noise ratio

text: signal-to-noise ratio

text: and therefore rejects

entity_name: Electromagnetic interference

text: radio frequency interference

text: better than an equal power amplitude modulation (AM) signal.  For this reason, most music is broadcast over

text: FM radio

text: The earliest radio communication systems, used during the first three decades of radio, 1887-1917, called the wireless telegraphy or "spark" era, used spark gap transmitters which generated radio waves by discharging a capacitance through an electric spark.  Each spark produced a transient pulse of radio waves consisting of a sinusoidal wave which decreased  rapidly exponentially to zero.   Spark transmitters produced strings of these damped waves, and could not generate the sinusoidal continuous waves which are modulated to carry sound in modern AM and FM transmission.    Thus spark transmitters could not transmit audio (sound), and instead transmitted information by radiotelegraphy; the transmitter was switched on and off rapidly by the operator using a telegraph key, creating different length pulses of these damped radio waves  ("dots" and "dashes") to spell out text messages in Morse code.

text: The earliest radio communication systems, used during the first three decades of radio, 1887-1917, called the

entity_name: Wireless telegraphy

text: wireless telegraphy

text: or "spark" era, used

entity_name: Spark-gap transmitter

text: spark gap transmitter

text: s which generated radio waves by discharging a

entity_name: Capacitance

text: capacitance

text: through an

entity_name: Electric spark

text: electric spark

text: .  Each spark produced a transient pulse of radio waves consisting of a sinusoidal wave which decreased  rapidly exponentially to zero.   Spark transmitters produced strings of these

entity_name: Damped wave

text: damped wave

text: s, and could not generate the sinusoidal

entity_name: Continuous wave

text: continuous wave

text: s which are

entity_name: Modulation

text: modulated

text: to carry sound in modern

text: AM

text: and

text: FM

text: transmission.    Thus spark transmitters could not transmit

entity_name: Audio signal

text: audio

text: (sound), and instead transmitted information by

text: radiotelegraphy

text: ; the transmitter was switched on and off rapidly by the operator using a

entity_name: Telegraph key

text: telegraph key

text: , creating different length pulses of these damped radio waves  ("dots" and "dashes") to spell out text messages in

text: Morse code

text: Greater St. Louis commands the 19th-largest media market in the United States, a position roughly unchanged for over a decade. All of the major U.S. television networks have affiliates in St. Louis, including KTVI 2 (Fox), KMOV 4 (CBS), KSDK 5 (NBC), KETC 9 (PBS), KPLR-TV 11 (CW), KDNL 30 (ABC), WRBU 46 (Ion), and WPXS 51 Daystar Television Network. Among the area's most popular radio stations are KMOX (AM sports and talk, notable as the longtime flagship station for St. Louis Cardinals broadcasts), KLOU (FM oldies), WIL-FM (FM country), WARH (FM adult hits), and KSLZ (FM Top 40 mainstream). St. Louis also supports public radio's KWMU, an NPR affiliate, and community radio's KDHX. All-sports stations, such as KFNS 590 AM "The Fan", WXOS "101.1 ESPN", and KSLG are also popular.

text: Greater St. Louis

text: commands the 19th-largest

text: media market

text: in the United States, a position roughly unchanged for over a decade. All of the major U.S. television networks have affiliates in St. Louis, including

text: KTVI

text: 2 (

text: Fox

text: KMOV

text: 4 (

text: CBS

text: KSDK

text: 5 (

text: NBC

text: KETC

text: 9 (

text: PBS

text: KPLR-TV

text: 11 (

text: CW

text: KDNL

text: 30 (

text: ABC

text: WRBU

text: 46 (

text: Ion

text: ), and

text: WPXS

text: Daystar Television Network

text: . Among the area's most popular radio stations are

text: KMOX

text: (AM sports and talk, notable as the longtime flagship station for St. Louis Cardinals broadcasts),

text: KLOU

text: (FM oldies),

text: WIL-FM

text: (FM country),

text: WARH

text: (FM adult hits), and

text: KSLZ

text: (FM Top 40 mainstream). St. Louis also supports

text: public radio

text: 's

text: KWMU

text: , an

text: NPR

text: affiliate, and

text: community radio

text: 's

text: KDHX

text: . All-sports stations, such as

text: KFNS

text: 590 AM "The Fan",

text: WXOS

text: "101.1 ESPN", and

text: KSLG

text: are also popular.

text: Continuous-wave radar is a type of radar system where a known stable frequency continuous-wave radio energy is transmitted and then received from any reflecting objects. Continuous-wave (CW) radar uses Doppler, which renders the radar immune to interference from large stationary objects and slow moving clutter.

text: Continuous-wave radar is a type of

text: radar

text: system where a known stable frequency

text: continuous-wave

text: radio

text: energy is transmitted and then received from any reflecting objects. Continuous-wave (CW) radar uses

text: Doppler

text: , which renders the radar immune to interference from large stationary objects and slow moving

text: clutter

text: While only a limited number of local stations can normally be received at satisfactory signal strengths in any given area, tuning into other channels may reveal weaker signals from adjacent areas. More consistently strong signals, especially those accentuated by unusual atmospheric conditions, can be achieved by improving the antenna system. The development of interest in TV-FM DX as a hobby can arise after more distant signals are either intentionally or accidentally discovered, leading to a serious interest in improving the listener's antenna and receiving installation for the purpose of actively seeking long-range television and radio reception. The TV-FM DX hobby is somewhat similar to other radio/electronic related hobbies such as amateur radio, Medium Wave DX, or short-wave radio, and organisations such as the Worldwide TV-FM DX Association have developed to coordinate and foster the further study and enjoyment of VHF/UHF television and FM broadcast DX.

text: While only a limited number of local stations can normally be received at satisfactory signal strengths in any given area, tuning into other channels may reveal weaker signals from adjacent areas. More consistently strong signals, especially those accentuated by unusual atmospheric conditions, can be achieved by improving the

text: antenna system

text: . The development of interest in TV-FM DX as a

text: hobby

text: can arise after more distant signals are either intentionally or accidentally discovered, leading to a serious interest in improving the listener's antenna and receiving installation for the purpose of actively seeking long-range television and radio reception. The TV-FM DX hobby is somewhat similar to other radio/electronic related hobbies such as

text: amateur radio

text: Medium Wave DX

text: , or

text: short-wave radio

text: , and organisations such as the Worldwide TV-FM DX Association have developed to coordinate and foster the further study and enjoyment of VHF/UHF television and FM broadcast DX.

text: An object can be located by measuring the characteristics of received radio waves. The radio waves may be transmitted by the object to be located, or they may be backscattered waves (as in radar or passive RFID).  A stud finder uses radiolocation when it uses radio waves rather than ultrasound.

text: An object can be located by measuring the characteristics of received radio waves. The radio waves may be transmitted by the object to be located, or they may be

text: backscatter

text: ed waves (as in radar or passive

text: RFID

text: ).  A

text: stud finder

text: uses radiolocation when it uses radio waves rather than

text: ultrasound

text: Several free-to-air terrestrial television channels are managed by companies that are directly affiliated with Televisyen Singapura (TV Singapura), Televisyen Malaysia (Singapura) (TV Malaysia (Singapura)), Radio Television Singapore (RTS), Singapore Broadcasting Corporation (SBC), Television Corporation of Singapore (TCS) and MediaCorp TV.

text: Several free-to-air terrestrial television channels are managed by companies that are directly affiliated with

text: Televisyen Singapura

text: (TV Singapura),

text: Televisyen Malaysia (Singapura)

text: (TV Malaysia (Singapura)),

text: Radio Television Singapore

text: (RTS),

text: Singapore Broadcasting Corporation

text: (SBC),

text: Television Corporation of Singapore

text: (TCS) and

text: MediaCorp TV

text: 1931 Cosmic radio waves

text: Cosmic radio waves

text: In 2008, the government of Felipe Calderón announced a scheme to move as many AM radio stations as possible to the FM band, in order to increase broadcast quality for listeners and permit the widespread development of future radio technologies on the FM band. Hundreds of stations, mostly outside of the largest metropolitan areas, either moved to FM after a year of AM-FM simulcasting or became AM and FM combo radio stations. Most AM stations that did not migrate were stations serving indigenous communities, in large metropolitan areas or border regions where there was no room to migrate stations, or stations that were forced to become AM-FM combos in order to guarantee the continuity of radio service in parts of their coverage areas.

text: In 2008, the government of

text: Felipe Calderón

text: announced a scheme to move as many AM radio stations as possible to the FM band, in order to increase broadcast quality for listeners and permit the widespread development of future radio technologies on the FM band. Hundreds of stations, mostly outside of the largest metropolitan areas, either moved to FM after a year of AM-FM simulcasting or became AM and FM combo radio stations. Most AM stations that did not migrate were stations serving indigenous communities, in large metropolitan areas or border regions where there was no room to migrate stations, or stations that were forced to become AM-FM combos in order to guarantee the continuity of radio service in parts of their coverage areas.

text: From Maxwell's equations we find that radio waves, as they exist in free space in the far field or Fraunhofer region behave as plane waves. In plane waves the electric field, magnetic field and direction of propagation are mutually perpendicular. To understand the various mechanisms that allow successful radio communications over NLOS paths we must consider how such plane waves are affected by the object or objects that visually obstruct the otherwise LOS path between the antennas. It is understood that the terms radio far field waves and radio plane waves are interchangeable.

text: From

text: Maxwell's equations

text: we find that radio waves, as they exist in

text: free space

text: in the

text: far field

text: or

text: Fraunhofer

text: region behave as

text: plane waves

text: . In plane waves the

text: electric field

text: magnetic field

text: and direction of propagation are mutually

text: perpendicular

text: . To understand the various mechanisms that allow successful radio communications over NLOS paths we must consider how such plane waves are affected by the object or objects that visually obstruct the otherwise LOS path between the antennas. It is understood that the terms radio far field waves and radio plane waves are interchangeable.

text: Typically, what is referred to as a ground wave radio signal is made up of a number of constituent waves. If the antennas are in the line of sight then there will be a direct wave as well as a reflected signal. As the names suggest the direct signal is one that travels directly between the two antennas and is not affected by the locality. There will also be a reflected signal as the transmission will be reflected by a number of objects including the earth's surface and any hills, or large buildings that may be present. In addition to this there is a surface wave. This tends to follow the curvature of the Earth and enables coverage beyond the horizon. It is the sum of all these components that is known as the ground wave. Beyond the horizon the direct and reflected waves are blocked by the curvature of the Earth, and the signal is purely made up of the diffracted surface wave. It is for this reason that surface wave is commonly called ground wave propagation.

text: Acoustic and radio-frequency wave-based technologies include:

text: Currently Radio Waves broadcasts only in Thimphu.

text: Also he initiated the first national television network in Nepal and several community radio networks. In 1992 he initiated Radio Democratic Voice of Burma in cooperation with Burmese opposition leaders. This short wave radio network played a significant role in the process for democracy in Burma.

text: Also he initiated the first national television network in

text: Nepal

text: and several community radio networks. In 1992 he initiated

text: Radio Democratic Voice of Burma

text: in cooperation with Burmese opposition leaders. This short wave radio network played a significant role in the process for democracy in

text: Burma

text: In simple antennas the feed usually consists of the feed antenna (driven element), the part of the antenna which actually converts the radio frequency currents to radio waves or vice versa, and the feed line (transmission line), which connects the feed antenna with the receiver or transmitter.   For example, in a rooftop Yagi television antenna, the feed consists of a dipole driven element, which converts the radio waves to an electric current, and a coaxial cable or twin lead transmission line which conducts the received signal from the driven element into the house to the television receiver.  The rest of the antenna consists of rods called parasitic elements, which strengthen reception from a given direction.

text: In simple antennas the feed usually consists of the feed antenna (

text: driven element

text: ), the part of the antenna which actually converts the

text: radio frequency

text: currents to radio waves or vice versa, and the

text: feed line

text: transmission line

text: ), which connects the feed antenna with the receiver or transmitter.   For example, in a rooftop

text: Yagi

text: television antenna

text: , the feed consists of a

text: dipole

text: driven element, which converts the radio waves to an electric current, and a

text: coaxial cable

text: or

text: twin lead

text: transmission line which conducts the received signal from the driven element into the house to the

text: television receiver

text: .  The rest of the antenna consists of rods called

text: parasitic element

text: s, which strengthen reception from a given direction.

text: In Europe, where a second AM broadcast band is used for longwave broadcasting, tuners may be fitted with both the standard medium wave and the additional longwave band. However, radios with only medium wave are also common, especially in countries where there are no longwave broadcasters. Rarely, radios are sold with only FM and longwave, but no medium wave band.

text: In Europe, where a second AM broadcast band is used for

text: longwave broadcasting

text: , tuners may be fitted with both the standard medium wave and the additional longwave band. However, radios with only medium wave are also common, especially in countries where there are no longwave broadcasters. Rarely, radios are sold with only FM and longwave, but no medium wave band.

text: Artificially generated radio waves are used for fixed and mobile radio communication, broadcasting, radar and other navigation systems, communications satellites, computer networks and innumerable other applications.  Radio waves are generated by radio transmitters and received by radio receivers.   Different frequencies of radio waves have different propagation characteristics in the Earth's atmosphere; long waves can diffract around obstacles like mountains and follow the contour of the earth (ground waves), shorter waves can reflect off the ionosphere and return to earth beyond the horizon (skywaves), while much shorter wavelengths bend or diffract very little and travel on a line of sight, so their propagation distances are limited to the visual horizon.

text: Artificially generated radio waves are used for fixed and mobile

text: radio communication

text: broadcasting

text: radar

text: and other navigation systems,

text: communications satellite

text: s, computer networks and innumerable other applications.  Radio waves are generated by

text: radio transmitter

text: s and received by

text: radio receiver

text: s.   Different frequencies of radio waves have different propagation characteristics in the Earth's atmosphere; long waves can

text: diffract

text: around obstacles like mountains and follow the contour of the earth (

text: ground wave

text: s), shorter waves can reflect off the

text: ionosphere

text: and return to earth beyond the horizon (

text: skywave

text: s), while much shorter wavelengths bend or diffract very little and travel on a

text: line of sight

text: , so their propagation distances are limited to the visual horizon.

text: Amateur television (ATV) is the transmission of broadcast quality video and audio over the wide range of frequencies of radio waves allocated for radio amateur (Ham) use. ATV is used for non-commercial experimentation, pleasure and public service events. Ham TV stations were on the air in many cities before commercial television stations came on the air. Various transmission standards are used, these include the broadcast transmission standards of NTSC in North America and Japan, and PAL or SECAM elsewhere, utilizing the full refresh rates of those standards. ATV includes the study of building of such transmitters and receivers, and the study of radio propagation of signals travelling between transmitting and receiving stations.

text: Amateur television (ATV) is the transmission of

text: broadcast quality

text: video

text: and

text: audio

text: over the wide range of frequencies of

text: radio wave

text: s allocated for

text: radio amateur

text: (Ham) use. ATV is used for

text: non-commercial

text: experimentation, pleasure and public service events. Ham TV stations were on the air in many cities before

text: commercial television

text: stations came on the air. Various transmission standards are used, these include the broadcast transmission standards of

text: NTSC

text: in

text: North America

text: and

text: Japan

text: , and

text: PAL

text: or

text: SECAM

text: elsewhere, utilizing the full

text: refresh rate

text: s of those standards. ATV includes the study of building of such

text: transmitter

text: s and

text: receivers

text: , and the study of

text: radio propagation

text: of signals travelling between transmitting and receiving stations.

text: There are 24 FM radio stations and 28 AM stations transmitting into or from Tegucigalpa.  Emisoras Unidas, the largest radio conglomerate in the country, is headquartered in Tegucigalpa and operates 94-SU 94.1 FM, Rock N' Pop 92.3 FM, Vox 101.9 FM, Suave 102.5 FM, Sterio Éxitos 88.1 FM, Radio Satélite 790 AM, XY Honduras 90.5 FM, and Radio HRN 92.9 FM.

text: A wave consists of successive troughs and crests, and the distance between two adjacent crests or troughs is called the wavelength. Waves of the electromagnetic spectrum vary in size, from very long radio waves the size of buildings to very short gamma rays smaller than atom nuclei. Frequency is inversely proportional to wavelength, according to the equation:

text: A wave consists of successive troughs and crests, and the distance between two adjacent crests or troughs is called the

text: wavelength

text: . Waves of the electromagnetic spectrum vary in size, from very long radio waves the size of buildings to very short gamma rays smaller than atom nuclei. Frequency is inversely proportional to wavelength, according to the equation:

text: In electromagnetics, an antenna's power gain or simply gain is a key performance number which combines the antenna's directivity and electrical efficiency.  As a transmitting antenna, the gain describes how well the antenna converts input power into radio waves headed in a specified direction. As a receiving antenna, the gain describes how well the antenna converts radio waves arriving from a specified direction into electrical power. When no direction is specified, "gain" is understood to refer to the peak value of the gain. A plot of the gain as a function of direction is called the radiation pattern.

text: In

text: electromagnetics

text: , an antenna's power gain or simply gain is a key performance number which combines the

text: antenna

text: 's

text: directivity

text: and electrical

text: efficiency

text: .  As a transmitting antenna, the gain describes how well the antenna converts input power into

text: radio wave

text: s headed in a specified direction. As a receiving antenna, the gain describes how well the antenna converts radio waves arriving from a specified direction into electrical power. When no direction is specified, "gain" is understood to refer to the peak value of the gain. A plot of the gain as a function of direction is called the

text: radiation pattern

text: There is no phone, television or radio service.  Short wave radio can pick up intermittent frequencies and satellite phones do operate. There are about five high frequency radio units in the province and operate on frequency 6815.

text: The radiation of many antennas shows a pattern of maxima or "lobes" at various angles, separated by "nulls", angles where the radiation falls to zero.  This is because the radio waves emitted by different parts of the antenna typically interfere, causing maxima at angles where the radio waves arrive at distant points in phase, and zero radiation at other angles where the radio waves arrive out of phase. In a directional antenna designed to project radio waves in a particular direction, the lobe in that direction is designed larger than the others and is called the "main lobe". The other lobes usually represent unwanted radiation and are called "sidelobes".  The axis through the main lobe is called the "principal axis" or "boresight axis".

text: The radiation of many antennas shows a pattern of maxima or "lobes" at various angles, separated by "

text: s", angles where the radiation falls to zero.  This is because the radio waves emitted by different parts of the antenna typically

text: interfere

text: , causing maxima at angles where the radio waves arrive at distant points

text: in phase

text: , and zero radiation at other angles where the radio waves arrive

text: out of phase

text: . In a

text: directional antenna

text: designed to project radio waves in a particular direction, the lobe in that direction is designed larger than the others and is called the "main lobe". The other lobes usually represent unwanted radiation and are called "

text: sidelobe

text: s".  The axis through the main lobe is called the "principal axis" or "

text: boresight

text: axis".

text: Two stations are operated by the University of Arkansas, KXUA 88.3 FM, which is the student-run station and KUAF, 91.3 FM, a national public radio (NPR) station.Cumulus Media owns seven stations in the Northwest Arkansas market, KFAY 1030 AM (news talk), KYNG 1590 AM, KQSM-FM 92.1 FM (ESPN Radio), KAMO-FM 94.3 FM (classic country music), KRMW 94.9 FM, KKEG 98.3 FM (classic rock), and KMCK-FM 105.7 FM (Top 40). IHeartMedia owns four radio stations in the area, including KIGL 93.3 FM (classic rock), KMXF 101.9 FM (Top 40), KKIX 103.9 FM (country music) and KEZA 107.9 FM (adult contemporary). Hog Radio, Inc. owns three radio stations in the area, including KAKS 99.5 FM (an ESPN Radio affiliate), KFMD-FM 101.5 (Classic hits), and KCYT 96.7 FM (country music). Butler Communications owns KXNA 104.9 FM (new rock), KREB 1190 AM, and KFFK 1930 AM. Kerm, Inc. operates two News Talk Information stations: KURM 790 AM and KLTK 1140 AM. KSEC 95.7 broadcasts in the Mexican Regional format and KFFK 1390 AM of Butler Communications broadcasts in the Spanish News/Talk format. Religious stations include KAYH 89.3 FM, KBNV 90.1 FM, and KLRC 90.9 FM. All sports radio station KUOA 1290 AM is rebroadcast on 105.3 in Fayetteville and features Arkansas Razorbacks coverage. KISR 95.9 FM is translated to Fayetteville from Fort Smith. Smaller operations include KOFC 1250 AM (news talk information) and KBVA 106.5 FM (variety).

text: Two stations are operated by the

text: University of Arkansas

text: KXUA

text: 88.3 FM, which is the student-run station and

text: KUAF

text: , 91.3 FM, a

text: national public radio

text: (NPR) station.

text: Cumulus Media

text: owns seven stations in the Northwest Arkansas market,

text: KFAY

text: 1030 AM (news talk),

text: KYNG

text: 1590 AM,

text: KQSM-FM

text: 92.1 FM (

text: ESPN Radio

text: KAMO-FM

text: 94.3 FM (classic country music),

text: KRMW

text: 94.9 FM,

text: KKEG

text: 98.3 FM (classic rock), and

text: KMCK-FM

text: 105.7 FM (Top 40).

text: IHeartMedia

text: owns four radio stations in the area, including

text: KIGL

text: 93.3 FM (

text: classic rock

text: KMXF

text: 101.9 FM (

text: Top 40

text: KKIX

text: 103.9 FM (

text: country music

text: ) and

text: KEZA

text: 107.9 FM (

text: adult contemporary

text: ). Hog Radio, Inc. owns three radio stations in the area, including

text: KAKS

text: 99.5 FM (an

text: ESPN Radio

text: affiliate), KFMD-FM 101.5 (

text: Classic hits

text: ), and

text: KCYT

text: 96.7 FM (

text: country music

text: ). Butler Communications owns

text: KXNA

text: 104.9 FM (new rock),

text: KREB

text: 1190 AM, and

text: KFFK

text: 1930 AM. Kerm, Inc. operates two

text: News Talk Information

text: stations:

text: KURM

text: 790 AM and

text: KLTK

text: 1140 AM.

text: KSEC

text: 95.7 broadcasts in the

text: Mexican Regional

text: format and KFFK 1390 AM of Butler Communications broadcasts in the

text: Spanish News/Talk

text: format. Religious stations include

text: KAYH

text: 89.3 FM,

text: KBNV

text: 90.1 FM, and

text: KLRC

text: 90.9 FM. All sports radio station

text: KUOA

text: 1290 AM is rebroadcast on 105.3 in Fayetteville and features

text: Arkansas Razorbacks

text: coverage.

text: KISR

text: 95.9 FM is

text: translated

text: to Fayetteville from

text: Fort Smith

text: . Smaller operations include

text: KOFC

text: 1250 AM (news talk information) and

text: KBVA

text: 106.5 FM (variety).

text: A curved phasefront may be synthesized from an infinite number of these "natural modes" i.e., from plane wave phasefronts oriented in different directions in space.  Far from its sources, an expanding spherical wave is locally tangent to a planar phase front (a single plane wave out of the infinite spectrum), which is transverse to the radial direction of propagation.  In this case, a Fraunhofer diffraction pattern is created, which emanates from a single spherical wave phase center.  In the near field, no single well-defined spherical wave phase center exists, so the wavefront isn't locally tangent to a spherical ball.  In this case, a Fresnel diffraction pattern would be created, which emanates from an extended source, consisting of a distribution of (physically identifiable) spherical wave sources in space.  In the near field, a full spectrum of plane waves is necessary to represent the Fresnel near-field wave, even locally.  A "wide" wave moving forward (like an expanding ocean wave coming toward the shore) can be regarded as an infinite number of "plane wave modes", all of which could (when they collide with something in the way) scatter independently of one other. These mathematical simplifications and calculations are the realm of Fourier analysis and synthesis – together, they can describe what happens when light passes through various slits, lenses or mirrors curved one way or the other, or is fully or partially reflected. Fourier optics forms much of the theory behind image processing techniques, as well as finding applications where information needs to be extracted from optical sources such as in quantum optics. To put it in a slightly more complex way, similar to the concept of frequency and time used in traditional  Fourier transform theory, Fourier optics makes use of the spatial frequency domain (k, k) as the conjugate of the spatial (x, y) domain. Terms and concepts such as transform theory, spectrum, bandwidth, window functions and sampling from one-dimensional signal processing are commonly used.

text: A curved phasefront may be synthesized from an infinite number of these "natural modes" i.e., from plane wave phasefronts oriented in different directions in space.  Far from its sources, an expanding spherical wave is locally tangent to a planar phase front (a single plane wave out of the infinite spectrum), which is transverse to the radial direction of propagation.  In this case, a

text: Fraunhofer diffraction

text: pattern is created, which emanates from a single spherical wave phase center.  In the near field, no single well-defined spherical wave phase center exists, so the wavefront isn't locally tangent to a spherical ball.  In this case, a

text: Fresnel diffraction

text: pattern would be created, which emanates from an extended source, consisting of a distribution of (physically identifiable) spherical wave sources in space.  In the near field, a full spectrum of plane waves is necessary to represent the Fresnel near-field wave, even locally.  A "wide"

text: wave

text: moving forward (like an expanding ocean wave coming toward the shore) can be regarded as an infinite number of "

text: plane wave modes

text: ", all of which could (when they collide with something in the way) scatter independently of one other. These mathematical simplifications and calculations are the realm of

text: Fourier analysis and synthesis

text: – together, they can describe what happens when light passes through various slits, lenses or mirrors curved one way or the other, or is fully or partially reflected. Fourier optics forms much of the theory behind

text: image processing techniques

text: , as well as finding applications where information needs to be extracted from optical sources such as in

text: quantum optics

text: . To put it in a slightly more complex way, similar to the concept of

text: frequency

text: and

text: time

text: used in traditional

text: Fourier transform theory

text: , Fourier optics makes use of the

text: spatial frequency

text: domain (k, k) as the conjugate of the spatial (x, y) domain. Terms and concepts such as transform theory, spectrum, bandwidth, window functions and sampling from one-dimensional

text: signal processing

text: are commonly used.

text: Some broadcasters use local transmitters to relay their broadcasts. Deutsche Welle broadcasts are relayed via Trincomalee on medium wave and short wave. Trans World Radio India broadcasts on medium wave using SLBC's transmitter in Puttalam. The International Broadcasting Bureau broadcasts programmes from Voice of America, Radio Azadi, Radio Free Afghanistan, Radio Free Asia, Radio Liberty and Radio Sawa on short wave using the relay station at Iranawila.

text: Some broadcasters use local transmitters to relay their broadcasts.

text: Deutsche Welle

text: broadcasts are relayed via

text: Trincomalee

text: on medium wave and short wave. Trans World Radio India broadcasts on medium wave using SLBC's transmitter in

text: Puttalam

text: . The

text: International Broadcasting Bureau

text: broadcasts programmes from

text: Voice of America

text: Radio Azadi

text: Radio Free Afghanistan

text: Radio Free Asia

text: Radio Liberty

text: and

text: Radio Sawa

text: on short wave using the relay station at Iranawila.

text: The dominant means of long distance communication in this band is skywave (skip) propagation, in which radio waves directed at an angle into the sky reflect (actually refract) back to Earth from layers of ionized atoms in the ionosphere.  By this method HF radio waves can travel beyond the horizon, around the curve of the Earth, and can be received at intercontinental distances.  However, suitability of this portion of the spectrum for such communication varies greatly with a complex combination of factors:

text: The dominant means of long distance communication in this band is

text: skywave

text: (skip) propagation, in which radio waves directed at an angle into the sky reflect (actually

text: refract

text: ) back to Earth from layers of ionized atoms in the ionosphere.  By this method HF radio waves can travel beyond the horizon, around the curve of the Earth, and can be received at intercontinental distances.  However, suitability of this portion of the spectrum for such communication varies greatly with a complex combination of factors:

text: Tropospheric ducting of radio and television signals is relatively common during the summer and autumn months, and is the result of change in the refractive index of the atmosphere at the boundary between air masses of different temperatures and humidities. Using an analogy, it can be said that the denser air at ground level slows the wave front a little more than does the rare upper air, imparting a downward curve to the wave travel.

text: Tropospheric ducting of radio and television signals is relatively common during the summer and autumn months, and is the result of change in the refractive index of the atmosphere at the boundary between air masses of different

text: temperature

text: s and

text: humidities

text: . Using an

text: analogy

text: , it can be said that the

text: denser

text: air at ground level slows the wave front a little more than does the rare upper air, imparting a downward curve to the wave travel.

text: The radio spectrum is the part of the electromagnetic spectrum from 3 Hz to 3000 GHz (3 THz).  Electromagnetic waves in this frequency range, called radio waves, are extremely widely used in modern technology, particularly in telecommunication.   To prevent interference between different users, the generation and transmission of radio waves is strictly regulated by national laws, coordinated by an international body, the International Telecommunication Union (ITU).

text: The radio spectrum is the part of the

text: electromagnetic spectrum

text: from 3

text: Hz

text: to 3000

text: GHz

text: THz

text: ).  Electromagnetic waves in this frequency range, called

text: radio wave

text: s, are extremely widely used in modern technology, particularly in

text: telecommunication

text: .   To prevent interference between different users, the generation and

text: transmission

text: of radio waves is strictly regulated by national laws, coordinated by an international body, the

text: International Telecommunication Union

text: (ITU).

text: Medium frequency (MF) is the ITU designation for radio frequencies (RF) in the range of 300 kHz to 3 MHz. Part of this band is the medium wave (MW) AM broadcast band. The MF band is also known as the hectometer band or hectometer wave as the wavelengths range from ten to one hectometer (1,000 to 100 m). Frequencies immediately below MF are denoted low frequency (LF), while the first band of higher frequencies is known as high frequency (HF). MF is mostly used for AM radio broadcasting, navigational radio beacons and maritime ship-to-shore communication.

text: Medium frequency (MF) is the

text: ITU

text: designation for

text: radio frequencies

text: (RF) in the range of 300 k

text: Hz

text: to 3 MHz. Part of this band is the

text: medium wave

text: (MW)

text: AM broadcast

text: band. The MF band is also known as the hectometer band or hectometer wave as the wavelengths range from ten to one

text: hectometer

text: (1,000 to 100 m). Frequencies immediately below MF are denoted

text: low frequency

text: (LF), while the first band of higher frequencies is known as

text: high frequency

text: (HF). MF is mostly used for

text: AM radio broadcasting

text: navigational radio beacons

text: and maritime ship-to-shore communication.

text: Research on the origin of seismic noise indicates that the low frequency part of the spectrum (below 1 Hz) is due to natural causes, chiefly ocean waves. In particular the peak between 0.1 and 0.3 Hz is clearly associated with the interaction of water waves of nearly equal frequencies but opposite directions. At high frequency (above 1 Hz), seismic noise is mainly produced by human activities such as road traffic and industrial work; but there are also natural sources, like rivers. Around 1 Hz, wind and other atmospheric phenomena are also a major source of ground vibrations.

text: Research on the origin of seismic noise indicates that the low frequency part of the

text: spectrum

text: (below 1 Hz) is due to natural causes, chiefly

text: ocean wave

text: s. In particular the peak between 0.1 and 0.3 Hz is clearly associated with the interaction of water waves of nearly equal frequencies but opposite directions. At high frequency (above 1 Hz), seismic noise is mainly produced by human activities such as road traffic and industrial work; but there are also natural sources, like rivers. Around 1 Hz, wind and other atmospheric phenomena are also a major source of ground vibrations.

text: The principal investigator for this mission is Erhan Kudeki of the University of Illinois. The purpose of this experiment is to study what disrupts Radio waves.

text: The principal investigator for this mission is Erhan Kudeki of the University of Illinois. The purpose of this experiment is to study what disrupts

text: Radio waves

text: In 1961, Azcárraga sold his 50 percent stake in RPM to Serna Martínez. By this time, RPM was shifting to a different business, the operation of its own radio stations. This stage of RPM's history began on January 1, 1957, when 660 AM XEBZ was relaunched as XERPM-AM. While XERPM was sold in the early 1970s to Radio Fórmula, RPM later came to operate other radio stations in Mexico City, especially after acquiring Radio Cadena Nacional in 1973 and transforming 1110 AM into a news and talk radio outlet known as Radio Red. At its height, RPM owned XERPM-AM 660, XERED-AM 1110, XEVIP-AM 1560, XHRED-FM 88.1 and XERPM-FM 103.3. In the late 1970s and 1980s, RPM shrunk in size. XERPM-FM was sold to Radio Fórmula in 1978, while XEVIP-AM was sold to Grupo Radio Centro in 1979. XHRCA-FM 91.3 would join Radio Programas de México in 1986.

text: In 1961, Azcárraga sold his 50 percent stake in RPM to Serna Martínez. By this time, RPM was shifting to a different business, the operation of its own radio stations. This stage of RPM's history began on January 1, 1957, when 660 AM XEBZ was relaunched as

text: XERPM-AM

text: . While XERPM was sold in the early 1970s to

text: Radio Fórmula

text: , RPM later came to operate other radio stations in Mexico City, especially after acquiring Radio Cadena Nacional in 1973 and transforming 1110 AM into a news and talk radio outlet known as Radio Red. At its height, RPM owned

text: XERPM-AM

text: XERED-AM

text: XEVIP-AM

text: XHRED-FM

text: 88.1 and

text: XERPM-FM

text: 103.3. In the late 1970s and 1980s, RPM shrunk in size. XERPM-FM was sold to

text: Radio Fórmula

text: in 1978, while XEVIP-AM was sold to Grupo Radio Centro in 1979.

text: XHRCA-FM

text: 91.3 would join Radio Programas de México in 1986.

text: Z-Wave is based on a proprietary design and a sole chip vendor. Although there have been a number of academic and practical security researches on home automation systems based on ZigBee and X10 protocols, research is still in its infancy to analyze the Z-Wave protocol stack layers, requiring the design of a radio packet capture device and related software to intercept Z-Wave communications. An early vulnerability was uncovered in AES-encrypted Z-Wave door locks that could be remotely exploited to unlock doors without the knowledge of the encryption keys, and due to the changed keys, subsequent network messages, as in "door is open", would be ignored by the established controller of the network. This vulnerability was not due to a flaw in the Z-Wave protocol specification but instead was an implementation error by the door lock manufacturer as stated in that same article.

text: Z-Wave is based on a proprietary design and a sole chip vendor. Although there have been a number of academic and practical security researches on home automation systems based on

text: ZigBee

text: and

text: protocols, research is still in its infancy to analyze the Z-Wave protocol stack layers, requiring the design of a radio packet capture device and related software to intercept Z-Wave communications. An early vulnerability was uncovered in AES-encrypted Z-Wave door locks that could be remotely exploited to unlock doors without the knowledge of the encryption keys, and due to the changed keys, subsequent network messages, as in "door is open", would be ignored by the established controller of the network. This vulnerability was not due to a flaw in the Z-Wave protocol specification but instead was an implementation error by the door lock manufacturer as stated in that same article.

text: WHHN is the second Catholic station in the Altonna market, the other being local low-power WMES which are not affiliated with each other nor co-owned. WHHN is owned and operated by Radio Maria Inc. and is a repeater of originating station KJMJ 580 kHz in Alexandria, Louisiana.WHHN's initial sign-on took place on Saturday morning, June 13, 2009. WHHN is the seventh of what is a network of repeaters originated by KJMJ which has been on the air since May 2000...the former KLBG and originally KALB (AM). In 2007, Radio Maria USA applied for ten additional frequencies on the FM band; up to that point it was only a six-station network comprising KJMJ (AM) with three repeaters (one AM and two FMs in Louisiana) with one AM in Texas and an FM and AM in Ohio. Audio streaming plays a huge part in its network operations as its repeater network slowly begins to grow. KJMJ with its repeaters and audiostream make up Radio Maria's only English language network. Radio Maria's international base is located in Erba (CO), within the Province of Como, Italy and is managed by its founder Emanuele Ferrario. In addition to its English language network, Radio Maria USA operates a Spanish-language network in Houston, New York City and Chicago using FM subcarriers along with an Italian language FM subcarrier also located in New York.  Audio streaming of their programming is offered as well from their respective websites.

text: WHHN is the second Catholic station in the Altonna market, the other being local low-power

text: WMES

text: which are not affiliated with each other nor co-owned. WHHN is owned and operated by Radio Maria Inc. and is a repeater of originating station

text: KJMJ

text: 580 kHz in

text: Alexandria, Louisiana

text: .WHHN's initial sign-on took place on Saturday morning, June 13, 2009. WHHN is the seventh of what is a network of repeaters originated by

text: KJMJ

text: which has been on the air since May 2000...the former KLBG and originally KALB (AM). In 2007, Radio Maria USA applied for ten additional frequencies on the FM band; up to that point it was only a six-station network comprising KJMJ (AM) with three repeaters (one AM and two FMs in Louisiana) with one AM in Texas and an FM and AM in Ohio. Audio streaming plays a huge part in its network operations as its repeater network slowly begins to grow. KJMJ with its repeaters and audiostream make up Radio Maria's only English language network. Radio Maria's international base is located in

text: Erba (CO)

text: , within the

text: Province of Como

text: Italy

text: and is managed by its founder Emanuele Ferrario. In addition to its English language network, Radio Maria USA operates a Spanish-language network in Houston, New York City and Chicago using FM subcarriers along with an Italian language FM subcarrier also located in New York.  Audio streaming of their programming is offered as well from their respective websites.

text: A changing electromagnetic field propagates away from its origin in the form of a wave. These waves travel in vacuum at the speed of light and exist in a wide spectrum of wavelengths. Examples of the dynamic fields of electromagnetic radiation (in order of increasing frequency): radio waves, microwaves, light (infrared, visible light  and ultraviolet), x-rays and gamma rays. In the field of particle physics this electromagnetic radiation is the manifestation of the electromagnetic interaction between charged particles.

text: A changing electromagnetic field propagates away from its origin in the form of a

text: wave

text: . These waves travel in vacuum at the

text: speed of light

text: and exist in a wide

text: spectrum

text: of

text: wavelength

text: s. Examples of the dynamic fields of

text: electromagnetic radiation

text: (in order of increasing frequency):

text: radio

text: waves,

text: microwave

text: s,

text: light

text: infrared

text: visible light

text: and

text: ultraviolet

text: x-ray

text: s and

text: gamma rays

text: . In the field of

text: particle physics

text: this electromagnetic radiation is the manifestation of the

text: electromagnetic interaction

text: between charged particles.

text: A ground station, earth station, or earth terminal is a terrestrial radio station designed for extraplanetary telecommunication with spacecraft (constituting part of the ground segment of the spacecraft system), or reception of radio waves from astronomical radio sources. Ground stations may be located either on the surface of the Earth, or in its atmosphere. Earth stations communicate with spacecraft by transmitting and receiving radio waves in the super high frequency or extremely high frequency bands (e.g., microwaves). When a ground station successfully transmits radio waves to a spacecraft (or vice versa), it establishes a telecommunications link. A principal telecommunications device of the ground station is the parabolic antenna.

text: A ground station, earth station, or earth terminal is a terrestrial

text: radio station

text: designed for extraplanetary

text: telecommunication

text: with

text: spacecraft

text: (constituting part of the

text: ground segment

text: of the spacecraft system), or reception of

text: radio waves

text: from

text: astronomical radio source

text: s. Ground stations may be located either on the surface of the Earth, or in its atmosphere. Earth stations communicate with spacecraft by transmitting and receiving radio waves in the

text: super high frequency

text: or

text: extremely high frequency

text: bands

text: (e.g.,

text: microwave

text: s). When a ground station successfully transmits radio waves to a spacecraft (or vice versa), it establishes a

text: telecommunications link

text: . A principal telecommunications device of the ground station is the

text: parabolic antenna

text: A parabolic antenna is an antenna that uses a parabolic reflector, a curved surface with the cross-sectional shape of a parabola, to direct the radio waves. The most common form is shaped like a dish and is popularly called a dish antenna or parabolic dish. The main advantage of a parabolic antenna is that it has high directivity. It functions similarly to a searchlight or flashlight reflector to direct the radio waves in a narrow beam, or receive radio waves from one particular direction only. Parabolic antennas have some of the highest gains, that is, they can produce the narrowest beamwidths, of any antenna type. In order to achieve narrow beamwidths, the parabolic reflector must be much larger than the wavelength of the radio waves used, so parabolic antennas are used in the high frequency part of the radio spectrum, at UHF and microwave (SHF) frequencies, at which the wavelengths are small enough that conveniently-sized reflectors can be used.

text: A parabolic antenna is an

text: antenna

text: that uses a

text: parabolic reflector

text: , a curved surface with the cross-sectional shape of a

text: parabola

text: , to direct the radio waves. The most common form is shaped like a

text: dish

text: and is popularly called a dish antenna or parabolic dish. The main advantage of a parabolic antenna is that it has high

text: directivity

text: . It functions similarly to a

text: searchlight

text: or

text: flashlight

text: reflector to direct the radio waves in a narrow beam, or receive radio waves from one particular direction only. Parabolic antennas have some of the highest

text: gain

text: s, that is, they can produce the narrowest

text: beamwidth

text: s, of any antenna type. In order to achieve narrow beamwidths, the parabolic reflector must be much larger than the

text: wavelength

text: of the radio waves used, so parabolic antennas are used in the high frequency part of the

text: radio spectrum

text: , at

text: UHF

text: and

text: microwave

text: SHF

text: ) frequencies, at which the wavelengths are small enough that conveniently-sized reflectors can be used.

text: The station was formed on 31 October 1988 when Viking Radio split its 1161 (originally said "Double-One-Six-One") medium wave frequency from its FM service. It has had many name changes, including "Viking Gold", "Classic Gold" (not to be confused with the service operated by UBC), "Classic Gold Radio", "Great Yorkshire Gold" and "Great Yorkshire Radio". Most of these formats, with the exception of "Viking Gold", shared programmes with the AM stations of the "Yorkshire Radio Network".

text: The station was formed on 31 October 1988 when Viking Radio split its 1161 (originally said "Double-One-Six-One")

text: medium wave

text: frequency from its FM service. It has had many name changes, including "Viking Gold", "

text: Classic Gold

text: " (not to be confused with the service operated by UBC), "Classic Gold Radio", "Great Yorkshire Gold" and "Great Yorkshire Radio". Most of these formats, with the exception of "Viking Gold", shared programmes with the AM stations of the "

text: Yorkshire Radio Network

text: The radio station relies on volunteers from the student body, college staff, and faculty to DJ in one-hour blocks.  Though the station has only been transmitting radio waves for a few years, its history dates back further when the broadcasts would air on an on-campus cable television channel.

text: Tesla's radio wave experiments in 1896 were conducted in Gerlach Hotel (later renamed The Radio Wave building), where he resided.

text: Although not nearly to the extent that AM radio has declined in neighboring Canada, AM radio has also begun to decline in the United States. To partially combat this, radio ownership groups have increasingly moved their signals to FM, either through low-power broadcast translators (primarily on small, independent and/or rural stations) or through simulcast on full-market FM stations. The AM-to-FM phenomenon began primarily in mid-sized markets, where there is more bandwidth and less competition, but has since progressed even to New York City, where as of 2012 sports-talk AM stations WEPN and WFAN have both acquired FM stations with the intent to either move or simulcast their AM programming. By 2013 most of the AM/FM simulcasts had been discontinued, in part due to redundancy and the fact that most listeners to AM stations stayed with AM while very few new listeners were picked up on the FM side.

text: Although not nearly to the extent that

text: AM radio

text: has declined in neighboring

text: Canada

text: , AM radio has also begun to decline in the United States. To partially combat this, radio ownership groups have increasingly moved their signals to FM, either through low-power broadcast translators (primarily on small, independent and/or rural stations) or through simulcast on full-market FM stations. The AM-to-FM phenomenon began primarily in mid-sized markets, where there is more bandwidth and less competition, but has since progressed even to

text: New York City

text: , where as of 2012 sports-talk AM stations

text: WEPN

text: and

text: WFAN

text: have both acquired FM stations with the intent to either move or simulcast their AM programming. By 2013 most of the AM/FM simulcasts had been discontinued, in part due to redundancy and the fact that most listeners to AM stations stayed with AM while very few new listeners were picked up on the FM side.

text: SBS Radio has three main radio services, Radio 1, Radio 2 and Radio 3, as well as a national FM service. Radio 1 is available on AM in Sydney, Melbourne, Canberra and Wollongong (1107, 1224, 1400 and 1485 respectively) while Radio 2 is available on FM in Sydney, Melbourne and Canberra (97.7, 93.1 and 105.5) and on AM in Wollongong (1035). Radio 3 is only available on digital platforms. The national service (branded simply as SBS Radio) is available throughout the rest of the nation through FM broadcasting (except in Newcastle, where it is available on AM) and on the Viewer Access Satellite Television satellite service, and is composed of material from Radios 1, 2 and 3. Additionally, a few community stations in areas without dedicated SBS Radio transmitters carry some SBS Radio content.

text: SBS Radio has three main radio services, Radio 1, Radio 2 and Radio 3, as well as a national FM service. Radio 1 is available on AM in Sydney, Melbourne, Canberra and Wollongong (1107, 1224, 1400 and 1485 respectively) while Radio 2 is available on FM in Sydney, Melbourne and Canberra (97.7, 93.1 and 105.5) and on AM in Wollongong (1035). Radio 3 is only available on digital platforms. The national service (branded simply as SBS Radio) is available throughout the rest of the nation through FM broadcasting (except in Newcastle, where it is available on AM) and on the

text: Viewer Access Satellite Television

text: satellite service, and is composed of material from Radios 1, 2 and 3. Additionally, a few community stations in areas without dedicated SBS Radio transmitters carry some SBS Radio content.

text: Radio spectrum pollution is the straying of waves in the radio and electromagnetic spectrums outside their allocations that cause problems for some activities.  It is of particular concern to radio astronomers.

text: Radio spectrum pollution is the straying of waves in the

text: radio

text: and

text: electromagnetic spectrum

text: s outside their allocations that cause problems for some activities.  It is of particular concern to radio

text: astronomer

text: s.

text: Infrared energy is just one part of the electromagnetic spectrum, which encompasses radiation from gamma rays, x-rays, ultra violet, a thin region of visible light, infrared, terahertz waves, microwaves, and radio waves. These are all related and differentiated in the length of their wave (wavelength). All objects emit a certain amount of black body radiation as a function of their temperatures.

text: Infrared energy is just one part of the

text: electromagnetic spectrum

text: , which encompasses radiation from

text: gamma rays

text: x-rays

text: ultra violet

text: , a thin region of

text: visible light

text: infrared

text: terahertz waves

text: microwaves

text: , and

text: radio waves

text: . These are all related and differentiated in the length of their wave (wavelength). All objects emit a certain amount of

text: black body

text: radiation as a function of their

text: temperature

text: s.

text: Gary Victor (born 9 July 1958 in Port-au-Prince), is a Haitian writer, playwright, and scriptwriter for television and radio. His radio sketches and uncompromising tone of his television series on the manners of the Haitian bourgeoisie, did not fail to make daily waves on the air. He also served as the General Secretary of the Senate of Haiti from 1996 to 2000.

text: Gary Victor (born 9 July 1958 in

text: Port-au-Prince

text: ), is a Haitian writer, playwright, and scriptwriter for television and radio. His radio sketches and uncompromising tone of his television series on the manners of the Haitian bourgeoisie, did not fail to make daily waves on the air. He also served as the General Secretary of the Senate of Haiti from 1996 to 2000.

text: Wireless communication is the transfer of information or power between two or more points that are not connected by an electrical conductor. The most common wireless technologies use radio. With radio waves distances can be short, such as a few meters for television or  as far as thousands or even millions of kilometers for deep-space radio communications.  It encompasses various types of fixed, mobile, and portable applications, including two-way radios, cellular telephones, personal digital assistants (PDAs), and wireless networking. Other examples of applications of radio wireless technology include GPS units, garage door openers, wireless computer mice, keyboards and headsets, headphones, radio receivers, satellite television, broadcast television and cordless telephones.

text: Wireless communication is the

text: transfer of information

text: or

text: power

text: between two or more points that are not connected by an electrical conductor. The most common wireless technologies use

text: radio

text: . With radio waves distances can be short, such as a few meters for

text: television

text: or  as far as thousands or even millions of kilometers for deep-space radio communications.  It encompasses various types of fixed, mobile, and portable applications, including

text: two-way radio

text: s,

text: cellular telephones

text: personal digital assistant

text: s (PDAs), and

text: wireless network

text: ing. Other examples of applications of radio wireless technology include

text: GPS

text: units,

text: garage door opener

text: s, wireless

text: computer mice

text: keyboards

text: and

text: headsets

text: headphone

text: s,

text: radio receiver

text: s,

text: satellite television

text: broadcast television

text: and

text: cordless telephone

text: s.

text: CKWV-FM (known on-air as "The Wave") is a Canadian radio station located in Nanaimo, British Columbia. It broadcasts on 102.3 FM and is owned by Island Radio, a division of the Jim Pattison Group.

text: CKWV-FM (known on-air as "The Wave") is a

text: Canadian

text: radio station

text: located in

text: Nanaimo

text: British Columbia

text: . It

text: broadcasts

text: on 102.3

text: FM

text: and is owned by Island Radio, a division of the

text: Jim Pattison Group

text: The term harmonic in its strictest sense describes any member of the harmonic series. The term is employed in various disciplines, including music and acoustics, electronic power transmission, radio technology, etc. It is typically applied to repeating signals, such as sinusoidal waves. A harmonic of such a wave is a wave with a frequency that is a positive integer multiple of the frequency of the original wave, known as the fundamental frequency. The original wave is also called 1st harmonic, the following harmonics are known as higher harmonics. As all harmonics are periodic at the fundamental frequency, the sum of harmonics is also periodic at that frequency. For example, if the fundamental frequency is 50 Hz, a common AC power supply frequency, the frequencies of the first three higher harmonics are 100 Hz (2nd harmonic), 150 Hz (3rd harmonic), 200 Hz (4th harmonic) and any addition of waves with these frequencies is periodic at 50 Hz.

text: The term harmonic in its strictest sense describes any member of the

text: harmonic series

text: . The term is employed in various disciplines, including music and acoustics, electronic power transmission, radio technology, etc. It is typically applied to repeating signals, such as

text: sinusoidal

text: waves. A harmonic of such a

text: wave

text: is a wave with a

text: frequency

text: that is a positive

text: integer

text: multiple of the frequency of the original wave, known as the

text: fundamental frequency

text: . The original

text: wave

text: is also called 1st harmonic, the following harmonics are known as higher harmonics. As all harmonics are periodic at the fundamental frequency, the sum of harmonics is also periodic at that frequency. For example, if the fundamental frequency is 50

text: Hz

text: , a common

text: AC

text: power supply frequency, the frequencies of the first three higher harmonics are 100 Hz (2nd harmonic), 150 Hz (3rd harmonic), 200 Hz (4th harmonic) and any addition of waves with these frequencies is periodic at 50 Hz.

text: The radio signal spreads out from the transmitter along the surface of the Earth. Instead of just travelling in a straight line the radio signals tend to follow the curvature of the Earth. This is because currents are induced in the surface of the earth and this action slows down the wave-front in this region, causing the wave-front of the radio communications signal to tilt downwards towards the Earth. With the wave-front tilted in this direction it is able to curve around the Earth and be received well beyond the horizon.

text: When the source of the waves is moving towards the observer, each successive wave crest is emitted from a position closer to the observer than the previous wave. Therefore, each wave takes slightly less time to reach the observer than the previous wave. Hence, the time between the arrival of successive wave crests at the observer is reduced, causing an increase in the frequency. While they are travelling, the distance between successive wave fronts is reduced, so the waves "bunch together".  Conversely, if the source of waves is moving away from the observer, each wave is emitted from a position farther from the observer than the previous wave, so the arrival time between successive waves is increased, reducing the frequency. The distance between successive wave fronts is then increased, so the waves "spread out".

text: When the source of the waves is moving towards the observer, each successive wave

text: crest

text: is emitted from a position closer to the observer than the previous wave. Therefore, each wave takes slightly less time to reach the observer than the previous wave. Hence, the time between the arrival of successive wave crests at the observer is reduced, causing an increase in the frequency. While they are travelling, the distance between successive wave fronts is reduced, so the waves "bunch together".  Conversely, if the source of waves is moving away from the observer, each wave is emitted from a position farther from the observer than the previous wave, so the arrival time between successive waves is increased, reducing the frequency. The distance between successive wave fronts is then increased, so the waves "spread out".

text: Radio waves generally are utilized by antennas of appropriate size (according to the principle of resonance), with wavelengths ranging from hundreds of meters to about one millimeter. They are used for transmission of data, via modulation. Television, mobile phones, wireless networking, and amateur radio all use radio waves. The use of the radio spectrum is regulated by many governments through frequency allocation.

text: Radio

text: waves generally are utilized by

text: antennas

text: of appropriate size (according to the principle of

text: resonance

text: ), with wavelengths ranging from hundreds of meters to about one millimeter. They are used for transmission of data, via

text: modulation

text: Television

text: mobile phone

text: s,

text: wireless networking

text: , and

text: amateur radio

text: all use radio waves. The use of the radio spectrum is regulated by many governments through

text: frequency allocation

text: Developed in 1964 the PM spectrum is one of the simplest descriptions for the energy distribution. It assumes that if the wind blows steadily for a long time over a large area, then the waves will eventually reach a point of equilibrium with the wind. This is known as a fully developed sea. Pierson and Moskowitz developed their spectrum from measurements in the North Atlantic during 1964, and presented the following relationship between energy distribution and wind: The observations of Pierson and Moskowitz were carefully re-analyzed in a 2003 investigation, which confirmed some values and proposed new thresholds to the original observations.

text: Developed in 1964 the PM spectrum is one of the simplest descriptions for the

text: energy distribution

text: . It assumes that if the wind blows steadily for a long time over a large area, then the waves will eventually reach a point of equilibrium with the wind. This is known as a fully developed sea. Pierson and Moskowitz developed their spectrum from measurements in the

text: North Atlantic

text: during 1964, and presented the following relationship between energy distribution and wind: The observations of Pierson and Moskowitz were carefully re-analyzed in a 2003 investigation, which confirmed some values and proposed new thresholds to the original observations.

text: KSRW (92.5 FM, TV-33. "Sierra Wave") is a radio station broadcasting an Alternative Rock music format and features programming from Westwood One.  The station is rebroadcast on 96.5 at Mammoth Lakes on translator K223BF, which in turn feeds another rebroadcast on 92.5 at Mammoth Mountain on translator K243AK. The station is also rebroadcast to central Mono County on translator K243BC on 	96.5 FM from Conway Summit, CA  KSRW also runs KSRW-LP, channel 33, broadcasting Local News and featuring programming from Outside Television, licensed to Mammoth Lakes, California. Licensed to Independence, California, USA, the KSRW 92.5 radio station serves the Bishop area. The station is currently owned by Benett Kessler, through licensee Benett Kessler II Trust.KSRW flipped to the Alternative Rock format on September 6, 2015, after having an adult contemporary format for many years.

text: KSRW (92.5

text: FM

text: TV

text: -33. "Sierra Wave") is a

text: radio station

text: broadcasting an

text: Alternative Rock

text: music format and features programming from

text: Westwood One

text: .  The station is rebroadcast on 96.5 at Mammoth Lakes on translator K223BF, which in turn feeds another rebroadcast on 92.5 at Mammoth Mountain on translator K243AK. The station is also rebroadcast to central Mono County on translator K243BC on 	96.5 FM from Conway Summit, CA  KSRW also runs KSRW-LP, channel 33, broadcasting

text: Local News

text: and featuring programming from

text: Outside Television

text: , licensed to

text: Mammoth Lakes, California

text: . Licensed to

text: Independence, California

text: , USA, the KSRW 92.5 radio station serves the

text: Bishop

text: area. The station is currently owned by Benett Kessler, through licensee Benett Kessler II Trust.KSRW flipped to the Alternative Rock format on September 6, 2015, after having an

text: adult contemporary

text: format for many years.

text: The first commercial FM broadcasting stations were in the United States, but initially they were primarily used to simulcast their AM sister stations, to broadcast lush orchestral music for stores and offices, to broadcast classical music to an upmarket listenership in urban areas, or for educational programming.  By the late 1960s, FM had been adopted by fans of "Alternative Rock" music ("A.O.R.—'Album Oriented Rock' Format"), but it wasn't until 1978 that listenership to FM stations exceeded that of AM stations in North America. During the 1980s and 1990s, Top 40 music stations and later even country music stations largely abandoned AM for FM. Today AM is mainly the preserve of talk radio, news, sports, religious programming, ethnic (minority language) broadcasting and some types of minority interest music. This shift has transformed AM into the "alternative band" that FM once was. (Some AM stations have begun to simulcast on, or switch to, FM signals to attract younger listeners and aid reception problems in buildings, during thunderstorms, and near high-voltage wires. Some of these stations now emphasize their presence on the FM dial.)

text: The first commercial FM broadcasting stations were in the United States, but initially they were primarily used to simulcast their AM sister stations, to broadcast lush orchestral music for stores and offices, to broadcast classical music to an upmarket listenership in urban areas, or for educational programming.  By the late 1960s, FM had been adopted by fans of "Alternative Rock" music ("A.O.R.—'

text: Album Oriented Rock

text: ' Format"), but it wasn't until 1978 that listenership to FM stations exceeded that of AM stations in North America. During the 1980s and 1990s, Top 40 music stations and later even country music stations largely abandoned AM for FM. Today AM is mainly the preserve of talk radio, news, sports, religious programming, ethnic (minority language) broadcasting and some types of minority interest music. This shift has transformed AM into the "alternative band" that FM once was. (Some AM stations have begun to simulcast on, or switch to, FM signals to attract younger listeners and aid reception problems in buildings, during thunderstorms, and near high-voltage wires. Some of these stations now emphasize their presence on the FM dial.)

text: In a multielement antenna array (such as a Yagi-Uda antenna), the driven element or active element is the element in the antenna (typically a metal rod) which is electrically connected to the receiver or transmitter.  In a transmitting antenna it is driven or excited by the RF current from the transmitter, and is the source of the radio waves.   In a receiving antenna it collects the incoming radio waves for reception, and converts them to tiny oscillating electric currents, which are applied to the receiver.  Multielement antennas like the Yagi typically consist of a driven element, connected to the receiver or transmitter through a feed line, and a number of other elements which are not driven, called parasitic elements.  The driven element is often a dipole.  The parasitic elements act as resonators and couple electromagnetically with the driven element, and serve to modify the radiation pattern of the antenna, directing the radio waves in one direction, increasing the gain of the antenna.

text: In a multielement

text: antenna array

text: (such as a

text: Yagi-Uda antenna)

text: , the driven element or active element is the element in the antenna (typically a metal rod) which is electrically connected to the

text: receiver

text: or

text: transmitter

text: .  In a transmitting antenna it is driven or excited by the

text: RF

text: current from the transmitter, and is the source of the radio waves.   In a receiving antenna it collects the incoming radio waves for reception, and converts them to tiny oscillating

text: electric current

text: s, which are applied to the

text: receiver

text: .  Multielement antennas like the Yagi typically consist of a driven element, connected to the receiver or transmitter through a

text: feed line

text: , and a number of other elements which are not driven, called

text: parasitic element

text: s.  The driven element is often a

text: dipole

text: .  The parasitic elements act as

text: resonator

text: s and couple electromagnetically with the driven element, and serve to modify the

text: radiation pattern

text: of the antenna, directing the radio waves in one direction, increasing the

text: gain

text: of the antenna.

text: The dryness of the air around and above Mt. Graham is particularly vital for EHF (extremely short wavelength radio) and far-infrared observations - a region of the spectrum where the electromagnetic waves are strongly attenuated by any water vapor or clouds in the air.

text: The dryness of the air around and above Mt. Graham is particularly vital for

text: EHF

text: (extremely short wavelength radio) and far-

text: infrared

text: observations - a region of the

text: spectrum

text: where the

text: electromagnetic wave

text: s are strongly

text: attenuated

text: by any

text: water vapor

text: or clouds in the air.

text: As the wavefront of the ground wave travels along the Earth's surface it is attenuated. The degree of attenuation is dependent upon a variety of factors. Frequency of the radio signal is one of the major determining factor as losses rise with increasing frequency. As a result, it makes this form of propagation impracticable above the bottom end of the HF portion of the spectrum (3 MHz). Typically a signal at 3.0 MHz will suffer an attenuation that may be in the region of 20 to 60 dB more than one at 0.5 MHz dependent upon a variety of factors in the signal path including the distance. In view of this it can be seen why even high power HF radio broadcast stations may only be audible for a few miles from the transmitting site via the ground wave.

text: After the release of the singles "Wild" and "Dr.", the first songs to be promoted from the album were "My Love" and "Copy That", which appeared in new commercials for cosmetics company, Vidal Sassoon. They premiered on the web first and later on television in October 2009. "My Love" would later make its radio premiere on J-Wave's Groove Line on October 27. Both "My Love" and "Copy That" were released as ringtones online on November 18. Two more songs from the album, "Fast Car" and "The Meaning Of Us" also made their radio premieres on November 23 and 24. The music videos for the two respective songs also premiered on music channels. In total, four new music videos have been produced for "Fast Car", "The Meaning Of Us", "Love Game", and "Defend Love." All four videos will appear on a DVD included with the album along with music videos for the previously released "Wild" and "Dr.".

text: After the release of the singles "Wild" and "Dr.", the first songs to be promoted from the album were "My Love" and "Copy That", which appeared in new commercials for cosmetics company,

text: Vidal Sassoon

text: . They premiered on the web first and later on television in October 2009. "My Love" would later make its radio premiere on

text: J-Wave

text: 's Groove Line on October 27. Both "My Love" and "Copy That" were released as ringtones online on November 18. Two more songs from the album, "Fast Car" and "The Meaning Of Us" also made their radio premieres on November 23 and 24. The music videos for the two respective songs also premiered on music channels. In total, four new music videos have been produced for "Fast Car", "The Meaning Of Us", "Love Game", and "Defend Love." All four videos will appear on a DVD included with the album along with music videos for the previously released "Wild" and "Dr.".

text: Fondation Radio-Enfant was originally granted a short-term license, with the call sign CIRC, on 96.5 FM for the duration of the Rendez-vous de la Francophonie in 2002 and in 2003, Fondation Radio-Enfant was also granted to operate at 1250 kHz on the AM dial, however, due to possible technical issues, the station never went on the air. The 96.5 frequency in Gatineau was later reassigned to CFTX-FM, and Fondation Radio-Enfant was granted a permanent AM license in early 2007 to operate at 1670 kHz.

text: Fondation Radio-Enfant was originally granted a short-term license, with the call sign CIRC, on 96.5 FM for the duration of the

entity_name: Organisation internationale de la Francophonie

text: Rendez-vous de la Francophonie

text: in 2002 and in 2003, Fondation Radio-Enfant was also granted to operate at 1250 kHz on the AM dial, however, due to possible technical issues, the station never went on the air. The 96.5 frequency in Gatineau was later reassigned to

text: CFTX-FM

text: , and Fondation Radio-Enfant was granted a permanent AM license in early 2007 to operate at 1670 kHz.

text: Radio waves in this band can be reflected or refracted from a layer of electrically charged atoms in the atmosphere called the ionosphere.  Therefore short waves directed at an angle into the sky can be reflected back to Earth at great distances, beyond the horizon.  This is called skywave or skip propagation.  Thus shortwave radio can be used for very long distance communication, in contrast to radio waves of higher frequency which travel in straight lines (line-of-sight propagation) and are limited by the visual horizon, about 40 miles.  Shortwave radio is used for broadcasting of voice and music to shortwave listeners over very large areas; sometimes entire continents or beyond. It is also used for military over-the-horizon radar, diplomatic communication, and two-way international communication by amateur radio enthusiasts for hobby, educational and emergency purposes.

text: Radio waves in this band can be reflected or refracted from a layer of electrically charged atoms in the atmosphere called the

text: ionosphere

text: .  Therefore short waves directed at an angle into the sky can be reflected back to Earth at great distances, beyond the horizon.  This is called

text: skywave

text: or skip

text: propagation

text: .  Thus shortwave radio can be used for very long distance communication, in contrast to radio waves of higher frequency which travel in straight lines (

text: line-of-sight propagation

text: ) and are limited by the visual horizon, about 40 miles.  Shortwave radio is used for

text: broadcasting

text: of voice and music to

text: shortwave listeners

text: over very large areas; sometimes entire continents or beyond. It is also used for military

text: over-the-horizon radar

text: , diplomatic communication, and two-way international communication by

text: amateur radio

text: enthusiasts for hobby, educational and emergency purposes.

text: In MASINT, the active signal source can be anywhere in the electromagnetic spectrum, from radio waves to X-rays, limited only by the propagation of the signal from the source. X-ray sources, for example, must be in very close proximity to the target, while lasers can illuminate a target from a high satellite orbit. While this discussion has emphasized the electromagnetic spectrum, there are also both active (e.g., sonar) and passive (e.g., hydrophone and microbarograph) acoustic sensors.

text: In MASINT, the active signal source can be anywhere in the electromagnetic spectrum, from radio waves to X-rays, limited only by the propagation of the signal from the source. X-ray sources, for example, must be in very close proximity to the target, while lasers can illuminate a target from a high satellite orbit. While this discussion has emphasized the electromagnetic spectrum, there are also both active (e.g., sonar) and passive (e.g.,

text: hydrophone

text: and

text: microbarograph

text: ) acoustic sensors.

text: Country music was aided by the U.S. Federal Communications Commission's (FCC) Docket 80–90, which led to a significant expansion of FM radio in the 1980s by adding numerous higher-fidelity FM signals to rural and suburban areas. At this point, country music was mainly heard on rural AM radio stations; the expansion of FM was particularly helpful to country music, which migrated to FM from the AM band as AM became overcome by talk radio (the country music stations that stayed on AM developed the classic country format for the AM audience). At the same time, beautiful music stations already in rural areas began abandoning the format (leading to its effective demise) to adopt country music as well. This wider availability of country music led to producers seeking to polish their product for a wider audience. Another force leading to changes in the country music industry was the changing sound of rock music, which was increasingly being influenced by the noisier, less melodic alternative rock scene. "New country" ended up absorbing rock influence from more electric musicians that were too melodic for modern rock but too electric for the classic country music sound. (A number of "classic rock" artists, especially Southern rock ones such as Charlie Daniels and Lynyrd Skynyrd, are more closely associated with the modern country music scene than that of the modern rock scene.)

text: Country music was aided by the U.S.

text: Federal Communications Commission

text: 's (FCC) Docket 80–90, which led to a significant expansion of

text: FM radio

text: in the 1980s by adding numerous higher-fidelity FM signals to rural and suburban areas. At this point, country music was mainly heard on rural

text: AM radio

text: stations; the expansion of FM was particularly helpful to country music, which migrated to FM from the AM band as AM became overcome by

text: talk radio

text: (the country music stations that stayed on AM developed the

text: classic country

text: format for the AM audience). At the same time,

text: beautiful music

text: stations already in rural areas began abandoning the format (leading to its effective demise) to adopt country music as well. This wider availability of country music led to producers seeking to polish their product for a wider audience. Another force leading to changes in the country music industry was the changing sound of rock music, which was increasingly being influenced by the noisier, less melodic

text: alternative rock

text: scene. "New country" ended up absorbing rock influence from more electric musicians that were too melodic for modern rock but too electric for the classic country music sound. (A number of "

text: classic rock

text: " artists, especially

text: Southern rock

text: ones such as

text: Charlie Daniels

text: and

text: Lynyrd Skynyrd

text: , are more closely associated with the modern country music scene than that of the modern rock scene.)

text: Maxwell's predicted waves included waves at very low frequencies compared to infrared, which in theory might be created by oscillating charges in an ordinary electrical circuit of a certain type. Attempting to prove Maxwell's equations and detect such low frequency electromagnetic radiation, in 1886 the physicist Heinrich Hertz built an apparatus to generate and detect what are now called radio waves. Hertz found the waves and was able to infer (by measuring their wavelength and multiplying it by their frequency) that they traveled at the speed of light. Hertz also demonstrated that the new radiation could be both reflected and refracted by various dielectric media, in the same manner as light. For example, Hertz was able to focus the waves using a lens made of tree resin. In a later experiment, Hertz similarly produced and measured the properties of microwaves. These new types of waves paved the way for inventions such as the wireless telegraph and the radio.

text: Maxwell's predicted waves included waves at very low frequencies compared to infrared, which in theory might be created by oscillating charges in an ordinary electrical circuit of a certain type. Attempting to prove Maxwell's equations and detect such low frequency electromagnetic radiation, in 1886 the physicist

text: Heinrich Hertz

text: built an apparatus to generate and detect what are now called

text: radio wave

text: s. Hertz found the waves and was able to infer (by measuring their wavelength and multiplying it by their frequency) that they traveled at the speed of light. Hertz also demonstrated that the new radiation could be both reflected and refracted by various dielectric media, in the same manner as light. For example, Hertz was able to focus the waves using a lens made of tree

text: resin

text: . In a later experiment, Hertz similarly produced and measured the properties of

text: microwave

text: s. These new types of waves paved the way for inventions such as the

text: wireless telegraph

text: and the

text: radio

text: Television advertising offers the benefit of reaching large numbers in a single exposure. Yet because it is a mass medium capable of being seen by nearly anyone, television lacks the ability to deliver an advertisement to highly targeted customers compared to other media outlets. Television networks are attempting to improve their targeting efforts. In particular, networks operating in the pay-to-access arena, such as those with channels on cable and satellite television, are introducing more narrowly themed programming (i.e., TV shows geared to specific interest groups) designed to appeal to selective audiences. However, television remains an option that is best for products that targeted to a broad market.

text: The term is also generally accepted to refer to television programming that is not produced by a broadcast or other media source for national or international distribution (broadcast syndication).  Usually programming of local interest is produced by either a Public, educational, and government access (PEG) television organization, cable TV operator or broadcast network affiliate stations that offer local radio news and television news.

text: The term is also generally accepted to refer to television programming that is not produced by a broadcast or other media source for national or international distribution (

text: broadcast syndication

text: ).  Usually programming of local interest is produced by either a

entity_name: Public, educational, and government access

text: Public, educational, and government access

text: (PEG) television organization,

text: cable TV

text: operator or

text: broadcast network

text: affiliate

text: stations that offer local

text: radio news

text: and

text: television news

text: Unlike modern AM radio stations that transmit a continuous radio frequency, whose amplitude (power) is modulated by an audio signal, the first radio transmitters transmitted information by wireless telegraphy (radiotelegraphy), the transmitter was turned on and off (on-off keying) to produce different length pulses of unmodulated carrier wave signal, "dots" and "dashes", that spelled out text messages in Morse code. As a result, early radio receiving apparatus merely had to detect the presence or absence of the radio signal, not convert it to audio.  The device that did this was called a detector.  The coherer was the most successful of many detector devices that were tried in the early days of radio.

text: Unlike modern AM radio stations that transmit a continuous radio frequency, whose amplitude (power) is

text: modulated

text: by an

text: audio

text: signal, the first

text: radio transmitter

text: s transmitted information by

text: wireless telegraphy

text: radiotelegraphy

text: ), the transmitter was turned on and off (

text: on-off keying

text: ) to produce different length pulses of unmodulated

text: carrier wave

text: signal, "dots" and "dashes", that spelled out text messages in

text: Morse code

text: . As a result, early radio receiving apparatus merely had to detect the presence or absence of the radio signal, not convert it to audio.  The device that did this was called a

text: detector

text: .  The coherer was the most successful of many detector devices that were tried in the early days of radio.

text: The high pressure gas exiting the cylinder initially flows in the form of a "wavefront" as all disturbances in fluids do. The exhaust gas pushes its way into the pipe which is already occupied by gas from previous cycles, pushing that gas ahead and causing a wave front. Once the gas flow stops, the wave continues, passing the energy to the next gas down stream and so on to the end of the pipe. If this wave encounters any change in cross section or temperature it will reflect a portion of its strength in the opposite direction to its travel. For example, a strong acoustic wave encountering an increase in area will reflect a weaker acoustic wave in the opposite direction. A strong acoustic wave encountering a decrease in area will reflect a strong acoustic wave in the opposite direction. The basic principle is described in wave dynamics.An expansion chamber makes use of this phenomenon by varying its diameter (cross section) and length to cause these reflections to arrive back at the cylinder at the desired time in the cycle.

text: The high

text: pressure

text: gas exiting the cylinder initially flows in the form of a "

text: wave

text: front" as all disturbances in fluids do. The exhaust gas pushes its way into the pipe which is already occupied by gas from previous cycles, pushing that gas ahead and causing a wave front. Once the gas flow stops, the wave continues, passing the energy to the next gas down stream and so on to the end of the pipe. If this wave encounters any change in

text: cross section

text: or

text: temperature

text: it will reflect a portion of its strength in the opposite direction to its travel. For example, a strong acoustic wave encountering an increase in area will reflect a weaker acoustic wave in the opposite direction. A strong acoustic wave encountering a decrease in area will reflect a strong acoustic wave in the opposite direction. The basic principle is described in

text: wave dynamics

text: .An expansion chamber makes use of this phenomenon by varying its diameter (cross section) and length to cause these reflections to arrive back at the cylinder at the desired time in the cycle.

text: Electromagnetic waves are typically described by any of the following three physical properties: the frequency f, wavelength λ, or photon energy E. Frequencies observed in astronomy range from  (1 GeV gamma rays) down to the local plasma frequency of the ionized interstellar medium (~1 kHz). Wavelength is inversely proportional to the wave frequency, so gamma rays have very short wavelengths that are fractions of the size of atoms, where as wavelengths on the opposite end of the spectrum can be as long as the universe. Photon energy is directly proportional to the wave frequency, so gamma ray photons have the highest energy (around a billion electron volts), while radio wave photons have very low energy (around a femtoelectronvolt). These relations are illustrated by the following equations:

text: Electromagnetic waves are typically described by any of the following three physical properties: the

text: frequency

text: f,

text: wavelength

text: λ

text: , or

text: photon

text: energy

text: E. Frequencies observed in astronomy range from  (1

text: GeV

text: gamma rays) down to the local

text: plasma frequency

text: of the ionized interstellar medium (~1 kHz). Wavelength is inversely proportional to the wave frequency, so gamma rays have very short wavelengths that are fractions of the size of

text: atom

text: s, where as wavelengths on the opposite end of the spectrum can be as long as the

text: universe

text: Photon energy

text: is directly proportional to the wave frequency, so gamma ray photons have the highest energy (around a billion

text: electron volt

text: s), while radio wave photons have very low energy (around a

text: femto

text: electronvolt). These relations are illustrated by the following equations:

text: Almost periodic function – Amplitude modulation – Amplitude – Beat – Chaos theory – Cyclic group – Diffraction – Doppler effect – Eigenstate – Eigenvalue – Fibonacci sequence – Fourier series – Frequency domain – Frequency spectrum – Hamiltonian (quantum mechanics) – Harmonic oscillator – Huygens–Fresnel principle – Longitudinal wave – Mechanical wave – Navier–Stokes equations – Partial differential equation – Periodic function – Permutation – Phase (waves) – Physics of music – Power spectrum – Signal – Sine wave – Spectrum of an operator – Translational symmetry – Transverse wave – Wave equation – Wave–particle duality – Wave – Waveform

text: Almost periodic function

text: Amplitude modulation

text: Amplitude

text: Beat

text: Chaos theory

text: Cyclic group

text: Diffraction

text: Doppler effect

text: Eigenstate

text: Eigenvalue

text: Fibonacci sequence

text: Fourier series

text: Frequency domain

text: Frequency spectrum

text: Hamiltonian (quantum mechanics)

text: Harmonic oscillator

text: Huygens–Fresnel principle

text: Longitudinal wave

text: Mechanical wave

text: Navier–Stokes equations

text: Partial differential equation

text: Periodic function

text: Permutation

text: Phase (waves)

text: Physics of music

text: Power spectrum

text: Signal

text: Sine wave

text: Spectrum of an operator

text: Translational symmetry

text: Transverse wave

text: Wave equation

text: Wave–particle duality

text: Wave

text: Waveform

text: Stations running The Joe Bev Hour including WGTD, Wisconsin Public Radio, Sound Stages Radio, WHRO-Norfolk, VA, The 1920s Radio Network, Toon Radio, Pawling Public Radio, Radio New Zealand, WGTD, Wisconsin Public Radio, Sound Stages Radio, WHRO-Norfolk, VA, The 1920s Radio Network, Toon Radio, Pawling Public Radio, Radio New Zealand, Prairie Public, Moab Public Radio, KAZU, WNMU-FM, KREV, WMMT, KAWC, Red River Radio Network, Marfa Public Radio, KCUR, WEZU, WSNC, Troy Public Radio, WCMU Public Radio, WRPI, KUAT, KUHF, KVMR, WRFA, KSVR Studios: Skagit Valley Radio, WHRV, KVMR, WUCF, WFIU, KRPS, KUT, WLRN, WTIP, WNCU, KEOS, KRUA, New Hampshire Public Radio, KGOU, Delta College Public Radio, WPSU, Northeast Indiana Public Radio, KMXT, KUFM - Montana Public Radio, WEFT, Northern Community Radio - KAXE & KBXE, WRVO, WYSO, WMPG, WGUC, KRPS, WEKU, Oregon Public Broadcasting, WXXI, Yellowstone Public Radio, Robin Hood Radio/ WHDD AM 1020/FM 91.9-WLHV FM 88.1 /WGHQ AM 920, WHRV, WVAS, WDCB, WMUK, KCCK, WAMC, Here and Now, WGBH, KWIT, KDUR, WGUC, WJFF, WILL, WNPR, WCAI/WNAN, KTNA, WKSU, WKMS, AMU, KSTX (KPAC), KERA, WFCR, WUAL, KZYX, KCPW, Stan, Delmarva Public Radio, KRCB, WKNO, KSJD, KFSR, KUHF, KQED, Spokane Public Radio, WUIS, WEKU, WEPS, WNCU, WPSU, KUOW, KUHB, KTXK, Raven Radio, WQUB, WCOM, WMUB, KGLT, KDNK, KMXT, KSFR, WVPE, South Dakota Public Broadcasting - Radio, KSUT, KUVO, KDLG, KVNF, KUHB, Yellowstone Public Radio, WERU, KSRQ, WKSU, KRCB, GAUF, WUSM, WDNA, KUGS, WGCU, KFAI, WUTS, East Village Radio, KAOS, KBBI.

text: Stations running The Joe Bev Hour including

text: WGTD

text: Wisconsin Public Radio

text: Sound Stages Radio

text: WHRO

text: Norfolk, VA

text: , The

text: 1920s Radio

text: Network,

text: Toon Radio

text: Pawling Public Radio

text: Radio New Zealand

text: In his Ultra high frequency (UHF) experiments, Hertz transmitted and received radio waves over short distances and showed that the properties of radio waves were consistent with Maxwell’s electromagnetic theory. He demonstrated that radio radiation had all the properties of waves (now called electromagnetic radiation), and discovered that the electromagnetic equations could be reformulated into a partial differential equation called the wave equation.

text: In his

text: Ultra high frequency

text: (UHF) experiments, Hertz transmitted and received radio waves over short distances and showed that the properties of radio waves were consistent with Maxwell’s electromagnetic theory. He demonstrated that radio radiation had all the properties of waves (now called

text: electromagnetic radiation

text: ), and discovered that the electromagnetic equations could be reformulated into a

text: partial differential equation

text: called the

text: wave equation

text: BBC Radio 5 used the medium wave frequencies previously used to transmit BBC Radio 2 from 23 November 1978 to 14 August 1990. It owed its existence to the broadcasting policy of the Conservative government of the time, who wished the BBC to end its longstanding practice of simulcasting its services on both AM and FM frequencies. A number of programmes, which were previously broadcast as opt-outs on one frequency only, would otherwise have been left without a home.

text: BBC Radio 5 used the

text: medium wave

text: frequencies previously used to transmit

text: BBC Radio 2

text: from 23 November 1978 to 14 August 1990. It owed its existence to the broadcasting policy of the

text: Conservative

text: government of the time, who wished the BBC to end its longstanding practice of

text: simulcast

text: ing its services on both

text: AM

text: and

text: FM

text: frequencies. A number of programmes, which were previously broadcast as opt-outs on one frequency only, would otherwise have been left without a home.

text: The wavelength is the distance from one peak of the wave's electric field (wave's peak/crest) to the next, and is inversely proportional to the frequency of the wave. The distance a radio wave travels in one second, in a vacuum, is  which is the wavelength of a 1 hertz radio signal. A 1 megahertz radio signal has a wavelength of .

text: The

text: wavelength

text: is the distance from one peak of the wave's electric field (wave's peak/crest) to the next, and is inversely proportional to the

text: frequency

text: of the wave. The distance a radio wave travels in one second, in a vacuum, is  which is the wavelength of a 1 hertz radio signal. A 1 megahertz radio signal has a wavelength of .

text: Second-wave feminism began in the 1960s and ran through the 1980s. At this time, women were making social and political gains and radical views were on the rise in society. This wave broadened feminist discussion from suffrage to a wide variety of issues such as domestic violence, rape, the workplace, sexuality, reproductive rights, etc., drawing in women of different races. The second-wave came alongside the civil rights and anti-war movement of the 1960s, which consistently attempted to give a voice to the minority, a positive for women. However, these movements also took away from the focus on feminism and gave more attention to Martin Luther King, Jr. and the Vietnam War than women’s rights. Feminists attempted to draw attention by forming women-only organizations, such as the National Organization for Women (NOW), and publishing papers that advocated women’s equality, such as “The BITCH Manifesto.” The major legislative focus of the wave was on the passage of the Equal Rights Amendment (ERA), which guaranteed social equality regardless of sex. The ERA made it to Congress for ratification, but failed to be ratified. The second-wave is said to have ended in the early 1980s with the discussion of sexuality and pornography, issues that were discussed during the third wave. With more advanced technology in the second wave, feminists used newspapers, television, radio, and published papers to spread their message.

text: Second-wave feminism

text: began in the 1960s and ran through the 1980s. At this time, women were making social and political gains and radical views were on the rise in society. This wave broadened feminist discussion from suffrage to a wide variety of issues such as domestic violence, rape, the workplace, sexuality, reproductive rights, etc., drawing in women of different races. The second-wave came alongside the

entity_name: African-American Civil Rights Movement (1954–1968)

text: civil rights

text: and

entity_name: Opposition to United States involvement in the Vietnam War

text: anti-war movement

text: of the 1960s, which consistently attempted to give a voice to the minority, a positive for women. However, these movements also took away from the focus on feminism and gave more attention to

text: Martin Luther King, Jr.

text: and the

text: Vietnam War

text: than women’s rights. Feminists attempted to draw attention by forming women-only organizations, such as the

text: National Organization for Women

text: (NOW), and publishing papers that advocated women’s equality, such as “The BITCH Manifesto.” The major legislative focus of the wave was on the passage of the

text: Equal Rights Amendment

text: (ERA), which guaranteed social equality regardless of sex. The ERA made it to Congress for ratification, but failed to be ratified. The second-wave is said to have ended in the early 1980s with the discussion of sexuality and pornography, issues that were discussed during the third wave. With more advanced technology in the second wave, feminists used newspapers, television, radio, and published papers to spread their message.

text: Radio waves were first identified in German physicist Heinrich Hertz's 1887 series of experiments to prove James Clerk Maxwell's electromagnetic theory.  Hertz used spark-excited dipole antennas to generate the waves and micrometer spark gaps attached to dipole and loop antennas to detect them.  These primitive devices are more accurately described as radio wave sensors, not "receivers", as they could only detect radio waves within about 100 feet of the transmitter, and were not used to attempt communication but were instead used as part of an experiment to verify a theoretical proof.

text: Radio waves were first identified in German physicist

text: Heinrich Hertz

text: 's 1887 series of experiments to prove James Clerk Maxwell's

text: electromagnetic theory

text: .  Hertz used spark-excited dipole antennas to generate the waves and micrometer

text: spark gap

text: s attached to

text: dipole

text: and

text: loop antenna

text: s to detect them.  These primitive devices are more accurately described as radio wave sensors, not "receivers", as they could only detect radio waves within about 100 feet of the transmitter, and were not used to attempt communication but were instead used as part of an experiment to verify a theoretical proof.

text: The wave heating theory, proposed in 1949 by Evry Schatzman, proposes that waves carry energy from the solar interior to the solar chromosphere and corona. The Sun is made of plasma rather than ordinary gas, so it supports several types of waves analogous to sound waves in air. The most important types of wave are magneto-acoustic waves and Alfvén waves. Magneto-acoustic waves are sound waves that have been modified by the presence of a magnetic field, and Alfvén waves are similar to ultra low frequency radio waves that have been modified by interaction with matter in the plasma. Both types of waves can be launched by the turbulence of granulation and super granulation at the solar photosphere, and both types of waves can carry energy for some distance through the solar atmosphere before turning into shock waves that dissipate their energy as heat.

text: The wave heating theory, proposed in 1949 by

text: Evry Schatzman

text: , proposes that waves carry energy from the solar interior to the solar chromosphere and corona. The Sun is made of

text: plasma

text: rather than ordinary gas, so it supports several types of waves analogous to

text: sound waves

text: in air. The most important types of wave are

text: magneto-acoustic wave

text: s and

text: Alfvén wave

text: s. Magneto-acoustic waves are sound waves that have been modified by the presence of a magnetic field, and Alfvén waves are similar to

text: ultra low frequency

text: radio waves

text: that have been modified by interaction with

text: matter

text: in the plasma. Both types of waves can be launched by the turbulence of

text: granulation

text: and

text: super granulation

text: at the solar photosphere, and both types of waves can carry energy for some distance through the solar atmosphere before turning into

text: shock waves

text: that dissipate their energy as heat.

text: The plane wave spectrum concept is the basic foundation of Fourier Optics. The plane wave spectrum is a continuous spectrum of uniform plane waves, and there is one plane wave component in the spectrum for every tangent point on the far-field phase front. The amplitude of that plane wave component would be the amplitude of the optical field at that tangent point. Again, this is true only in the far field, defined as: Range = 2 D / λ where D is the maximum linear extent of the optical sources and λ is the wavelength (Scott [1998]). The plane wave spectrum is often regarded as being discrete for certain types of periodic gratings, though in reality, the spectra from gratings are continuous as well, since no physical device can have the infinite extent required to produce a true line spectrum.

text: The

text: plane wave

text: spectrum concept is the basic foundation of Fourier Optics. The plane wave spectrum is a continuous spectrum of uniform plane waves, and there is one plane wave component in the spectrum for every tangent point on the far-field phase front. The amplitude of that plane wave component would be the amplitude of the optical field at that tangent point. Again, this is true only in the far field, defined as: Range = 2 D / λ where D is the maximum linear extent of the optical sources and λ is the wavelength (Scott [1998]). The plane wave spectrum is often regarded as being discrete for certain types of periodic gratings, though in reality, the spectra from gratings are continuous as well, since no physical device can have the infinite extent required to produce a true line spectrum.

text: Non-commercial radio stations include NPR affiliates KUOW-FM 94.9 and KNKX 88.5 (Tacoma), as well as classical music station KING-FM 98.1. Other non-commercial stations include KEXP-FM 90.3 (affiliated with the UW), community radio KBCS-FM 91.3 (affiliated with Bellevue College), and high school radio KNHC-FM 89.5, which broadcasts an electronic dance music radio format and is owned by the public school system and operated by students of Nathan Hale High School. Many Seattle radio stations are also available through Internet radio, with KEXP in particular being a pioneer of Internet radio. Seattle also has numerous commercial radio stations. In a March 2012 report by the consumer research firm Arbitron, the top FM stations were KRWM (adult contemporary format), KIRO-FM (news/talk), and KISW (active rock) while the top AM stations were KOMO (AM) (all news), KJR (AM) (all sports), KIRO (AM) (all sports).

text: Non-commercial

text: radio stations include

text: NPR

text: affiliates

text: KUOW-FM

text: 94.9 and

text: KNKX

text: 88.5 (Tacoma), as well as

text: classical music

text: station

text: KING-FM

text: 98.1. Other non-commercial stations include

text: KEXP-FM

text: 90.3 (affiliated with the UW),

text: community radio

text: KBCS-FM

text: 91.3 (affiliated with

text: Bellevue College

text: ), and

text: high school radio

text: KNHC-FM

text: 89.5, which broadcasts an

text: electronic dance music

text: radio format

text: and is owned by the public school system and operated by students of

text: Nathan Hale High School

text: . Many Seattle radio stations are also available through

text: Internet radio

text: , with KEXP in particular being a pioneer of Internet radio. Seattle also has numerous commercial radio stations. In a March 2012 report by the consumer research firm

text: Arbitron

text: , the top FM stations were

text: KRWM

text: adult contemporary

text: format),

text: KIRO-FM

text: news/talk

text: ), and

text: KISW

text: active rock

text: ) while the top AM stations were

text: KOMO (AM)

text: all news

text: KJR (AM)

text: all sports

text: KIRO (AM)

text: (all sports).

text: Most radio systems in the 20th century used frequency modulation (FM) or amplitude modulation (AM) to make the carrier carry information. In the case of single-sideband modulation (SSB), the carrier is suppressed (and in some forms of SSB, eliminated). The carrier must be reintroduced at the receiver by a beat frequency oscillator (BFO). The frequency of a radio or television station is actually the carrier wave's center frequency.

text: Most radio systems in the 20th century used

text: frequency modulation

text: (FM) or

text: amplitude modulation

text: (AM) to make the carrier carry information. In the case of

text: single-sideband modulation

text: (SSB), the carrier is suppressed (and in some forms of SSB, eliminated). The carrier must be reintroduced at the receiver by a

text: beat frequency oscillator

text: (BFO). The frequency of a radio or television station is actually the carrier wave's

text: center frequency

text: Beginning in 1975, Carroll began television advertisement. For most of the next fifteen years Carroll performed commercials in the same frenetic manner he had for radio. One of his more memorable promotions was for Crazy Eddie's annual "Christmas in August" sale, where he would dress in a Santa suit and do the commercial while stagehands threw fake snowballs at him. Carroll also had a trademark look in each commercial, wearing a blue suit with a lighter blue turtleneck shirt in almost all of his appearances (even during later years). Carroll even appeared in a Spanish-language Crazy Eddie advertisement, although he did not have a speaking role; instead, his appearance consisted of him holding a radio to his ear as he walked behind the commercial's spokesman, stopping only to wave at the camera several times.

text: Beginning in 1975, Carroll began television advertisement. For most of the next fifteen years Carroll performed commercials in the same frenetic manner he had for radio. One of his more memorable promotions was for Crazy Eddie's annual "Christmas in August" sale, where he would dress in a

text: Santa

text: suit and do the commercial while stagehands threw fake snowballs at him. Carroll also had a trademark look in each commercial, wearing a blue suit with a lighter blue turtleneck shirt in almost all of his appearances (even during later years). Carroll even appeared in a Spanish-language Crazy Eddie advertisement, although he did not have a speaking role; instead, his appearance consisted of him holding a radio to his ear as he walked behind the commercial's spokesman, stopping only to wave at the camera several times.

text: Two radio stations, one in Ouagadougou and one in Bobo-Dioulasso, are run by the government radio corporation Radiodiffusion Nationale. Broadcasts are in French and 13 indigenous languages, using both medium wave (AM) and FM frequencies. RTB also maintains a worldwide short-wave news broadcast (Radio Nationale Burkina) in the French language from the capital at Ouagadougou using a 100Kw transmitter on 4.815 and 5.030 MHz.

text: Two radio stations, one in

text: Ouagadougou

text: and one in

text: Bobo-Dioulasso

text: , are run by the government radio corporation Radiodiffusion Nationale. Broadcasts are in French and 13 indigenous languages, using both

text: medium wave

text: AM

text: ) and

text: FM

text: frequencies. RTB also maintains a worldwide short-wave news broadcast (Radio Nationale Burkina) in the French language from the capital at Ouagadougou using a 100Kw transmitter on 4.815 and 5.030 MHz.

text: NIRT International Radio was broadcast on: 1555 kHz AM (Medium Wave) and 106 MHz FM (stereo) in Tehran.

text: Kurzwellen is one of a series of works dating from the 1960s which Stockhausen designated as "process" compositions. These works in effect separate the "form" from the "content" by presenting the performers with a series of transformation signs which are to be applied to material that may vary considerably from one performance to the next. In Kurzwellen and three subsequent works (Spiral for a soloist, Pole for two, and Expo for three), this material is to be drawn spontaneously during the performance from short-wave radio broadcasts . While this separate treatment of the genetic rules for development had existed in Stockhausen's earlier compositions, the emphasis on the process of transformation and less specificity of what is to be transformed is taken further than ever before in Kurzwellen . The overall formal process is therefore fixed, whereas the sound materials are extremely variable . The processes, indicated primarily by plus, minus, and equal signs, constitute the composition and, despite the unpredictability of the materials, these processes can be heard from one performance to another as being "the same" . While the use of radios in concert works dates back at least to 1942 with  John Cage's Credo in Us, and Stockhausen may well have gotten the idea of using radios from Cage, their approaches could not have been more different. For Cage, the type of radio is a matter of indifference, since their purpose is merely to fill in prescribed time units with any sort of sound at all. Stockhausen, on the other hand, prescribed short-wave receivers because of their capability of bringing in broadcasts from far away, and for the rich variety of available sounds. These sounds are also not used indiscriminately: the performers are to search for and select only materials suitable for improvisational transformations .

text: Kurzwellen is one of a series of works dating from the 1960s which Stockhausen designated as "

text: process

text: " compositions. These works in effect separate the "form" from the "content" by presenting the performers with a series of transformation signs which are to be applied to material that may vary considerably from one performance to the next. In Kurzwellen and three subsequent works (

text: Spiral

text: for a soloist,

text: Pole

text: for two, and

text: Expo

text: for three), this material is to be drawn spontaneously during the performance from

text: short-wave

text: radio broadcasts . While this separate treatment of the genetic rules for development had existed in Stockhausen's earlier compositions, the emphasis on the process of transformation and less specificity of what is to be transformed is taken further than ever before in Kurzwellen . The overall formal process is therefore fixed, whereas the sound materials are extremely variable . The processes, indicated primarily by plus, minus, and equal signs, constitute the composition and, despite the unpredictability of the materials, these processes can be heard from one performance to another as being "the same" . While the use of radios in concert works dates back at least to 1942 with

text: John Cage

text: 's Credo in Us, and Stockhausen may well have gotten the idea of using radios from Cage, their approaches could not have been more different. For Cage, the type of radio is a matter of indifference, since their purpose is merely to fill in prescribed time units with any sort of sound at all. Stockhausen, on the other hand, prescribed short-wave receivers because of their capability of bringing in broadcasts from far away, and for the rich variety of available sounds. These sounds are also not used indiscriminately: the performers are to search for and select only materials suitable for improvisational transformations .

text: Furthermore, electromagnetic energy is light energy, but only a small part of it is visible light. This energy travels in waves. Shorter wavelengths, such as visible light and infrared, carry more energy per photon than longer waves, such as microwaves and radio waves. For the sciences, the light spectrum is known as the electromagnetic spectrum.

text: Furthermore, electromagnetic energy is light energy, but only a small part of it is

text: visible light

text: . This energy travels in waves. Shorter wavelengths, such as visible light and

text: infrared

text: , carry more energy per

text: photon

text: than longer waves, such as

text: microwave

text: s and

text: radio waves

text: . For the

text: science

text: s, the light spectrum is known as the

text: electromagnetic spectrum

text: The Premios Ondas  (Spanish: literally "wave awards", also known in English as the Ondas Awards) have been given since 1954 by Radio Barcelona, a subsidiary of Cadena SER, in recognition of professionals in the fields of radio and television broadcasting, the cinema, and the music industry.

text: The Premios Ondas  (

text: Spanish

text: : literally "wave awards", also known in English as the Ondas Awards) have been given since 1954 by Radio Barcelona, a subsidiary of

text: Cadena SER

text: , in recognition of professionals in the fields of

text: radio

text: and

text: television

text: broadcasting, the

text: cinema

text: , and the

text: music industry

text: The Kaluga Oblast Radio and Television Broadcasting Center, the branch of Russian Television and Radio Broadcasting Network (FGUP), is the main operator broadcasting television and radio programs in the oblast.  As of 2007, 100% of the oblast territory has been covered by television broadcasting services.  TV programs of the regional television company and radio local news programs are broadcast in the entire territory of the oblast through satellite transmission equipment. In addition, cable television networks are being developed in the oblast. Starting from 2013, a federal project will be launched to introduce digital television and radio broadcasting with an increased number of TV and radio channels and improved quality of services.

text: The Kaluga Oblast Radio and Television Broadcasting Center, the branch of

entity_name: Russian Television and Radio Broadcasting Network

text: Russian Television and Radio Broadcasting Network

text: (FGUP), is the main operator broadcasting television and radio programs in the oblast.  As of 2007, 100% of the oblast territory has been covered by television broadcasting services.  TV programs of the regional television company and radio local news programs are broadcast in the entire territory of the oblast through satellite transmission equipment. In addition,

text: cable television

text: networks are being developed in the oblast. Starting from 2013, a

text: federal project will be launched to introduce digital television

text: and radio broadcasting with an increased number of TV and radio channels and improved quality of services.

text: In 1992, Al Germond and his business partners, John Ott and David Baugher, bought KFRU-AM under the company name of Columbia AM.  Later came additional radio stations, including KBXR-FM 102.3, KOQL-FM 106.1, KJMO-FM, KLIK-AM, KBBM-FM and KZJF-FM, as well as ownership of the Columbia Business Times publishing products.

text: Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light.  Radio waves have frequencies as high as 300 GHz to as low as 3 kHz, though some definitions describe waves above 1 or 3 GHz as microwaves, or include waves of any lower frequency. At 300 GHz, the corresponding wavelength is , and at 3 kHz is . Like all other electromagnetic waves, they travel at the speed  of light. Naturally occurring radio waves are generated by lightning, or by astronomical objects.

text: Radio waves are a type of

text: electromagnetic radiation

text: with

text: wavelength

text: s in the

text: electromagnetic spectrum

text: longer than

text: infrared

text: light.  Radio waves have

text: frequencies

text: as high as 300

text: GHz

text: to as low as 3

text: kHz

text: , though some definitions describe waves above 1 or 3 GHz as

text: microwaves

text: , or include waves of any lower frequency. At 300 GHz, the corresponding wavelength is , and at 3 kHz is . Like all other electromagnetic waves, they travel at the

text: speed  of light

text: . Naturally occurring radio waves are generated by

text: lightning

text: , or by

text: astronomical objects

text: A radio transmitter is an electronic circuit which transforms electric power from a battery or electrical mains into a radio frequency alternating current, which reverses direction millions to billions of times per second.  The energy in such a rapidly reversing current can radiate off a conductor (the antenna) as electromagnetic waves (radio waves).  The transmitter also impresses information such as an audio or video signal onto the radio frequency current to be carried by the radio waves.  When they strike the antenna of a radio receiver, the waves excite similar (but less powerful) radio frequency currents in it.  The radio receiver extracts the information from the received waves.  A practical radio transmitter usually consists of these parts:

text: A radio transmitter is an

text: electronic circuit

text: which transforms electric power from a battery or

text: electrical mains

text: into a

text: radio frequency

text: alternating current

text: , which reverses direction millions to billions of times per second.  The energy in such a rapidly reversing current can radiate off a conductor (the antenna) as

text: electromagnetic wave

text: s (radio waves).  The transmitter also impresses information such as an audio or video signal onto the radio frequency current to be carried by the radio waves.  When they strike the antenna of a

text: radio receiver

text: , the waves excite similar (but less powerful) radio frequency currents in it.  The radio receiver extracts the information from the received waves.  A practical radio transmitter usually consists of these parts:

text: According to the superposition principle of quantum mechanics, wave functions can be added together and multiplied by complex numbers to form new wave functions and form a Hilbert space. The inner product between two wave functions is a measure of the overlap between the corresponding physical states and is used in the foundational probabilistic interpretation of quantum mechanics, the Born rule, relating transition probabilities to inner products.   The Schrödinger equation determines how wave functions evolve over time. A wave function behaves qualitatively like other waves, such as water waves or waves on a string, because the Schrödinger equation is mathematically a type of wave equation. This explains the name "wave function", and gives rise to wave–particle duality. However, the wave function in quantum mechanics describes a kind of physical phenomenon, still open to different interpretations, which fundamentally differs from that of classic mechanical waves.

text: According to the

text: superposition principle

text: of quantum mechanics, wave functions can be added together and multiplied by complex numbers to form new wave functions and form a

text: Hilbert space

text: . The inner product between two wave functions is a measure of the overlap between the corresponding physical states and is used in the foundational probabilistic interpretation of quantum mechanics, the

text: Born rule

text: , relating transition probabilities to inner products.   The Schrödinger equation determines how wave functions evolve over time. A wave function behaves qualitatively like other

text: wave

text: s, such as

text: water wave

text: s or waves on a string, because the Schrödinger equation is mathematically a type of

text: wave equation

text: . This explains the name "wave function", and gives rise to

text: wave–particle duality

text: . However, the wave function in quantum mechanics describes a kind of physical phenomenon, still open to different

text: interpretations

text: , which fundamentally differs from that of classic mechanical waves.

text: The easy reception of powerful medium-wave foreign stations like Radio Luxembourg, Radio Montecarlo or Radio Koper allowed Italian youngsters to bypass the mediatic block, and stay updated to the latest anglosaxon trends (some radio enthusiasts even managed to catch the elusive Channel's "pirate stations" like Radio Caroline, and the GermanTV shows like Beat Club)

text: The easy reception of powerful medium-wave foreign stations like Radio Luxembourg, Radio Montecarlo or Radio Koper allowed Italian youngsters to bypass the mediatic block, and stay updated to the latest anglosaxon trends (some radio enthusiasts even managed to catch the elusive Channel's "pirate stations" like Radio Caroline, and the GermanTV shows like

text: Beat Club

text: WSYY-FM (94.9 FM) is a radio station broadcasting for approximately 18¼ hours per day (from 4:55AM through 11:10PM ET), under the slogan, "Radio With An Attitude". Playing a mix of Classic Hits, Adult Contemporary, Classic Rock, Oldies, Contemporary Pop Music and Today's Hot New Country, the station broadcasts an Adult Hits/Full-Service format for approximately 16 hours per day, from 6:00AM through 10:00PM ET (reserving the first and, also, the final hour of their broadcast day to When Radio Was). The Mountain 94.9 carries local high school sports in season. The Mountain 94.9 had also carried the complete schedule of Red Sox Baseball (from 1997 through 2015, prior to becoming a Former Affiliate in 2016, which was when Millinocket's affiliation with the Red Sox Baseball would ultimately be transferred over to co-owned WSYY-AM, thus concluding the frequent interruptions to the music on The Mountain 94.9 during Baseball season). The station currently features programming from CBS Radio and carries CBS Radio News at the top of every hour (and has been an affiliate of that network for many decades). Licensed to Millinocket, Maine, USA, the station's broadcast signal serves the Central Penobscot County, Eastern Piscataquis County and Southern Aroostook County Maine areas, and the station is licensed to service the town of Millinocket, Maine, the very town where its Studios/Offices and Transmitter Tower Site are all located within.  The station is currently owned by Katahdin Communications, Inc. WSYY-FM originally went on the air in 1978 on 97.7 FM as WKTR, upgrading to its current facilities in 1984 on 94.9. Prior to their The Mountain 94.9 branding, WSYY-FM used to be referred to as North Country 95, airing a full-time Country Music format. The current format, branding, and slogan was probably adopted around March 1, 2004, when Katahdin Communications, Inc. assumed control of WSYY-FM & WSYY-AM from Katahdin Timberlands, LLC (as a result of the radio station facing increasing land disputes), initially as a short term lease agreement but the transfer of ownership ultimately became permanent. Those same land disputes would eventually lead to a loss of WSYY-FM's 23,500 watt transmitter location (featuring an antenna HAAT of 211 meters); as a result of this, WSYY-FM may have been operating under a Special Temporary Authority License (a 12,000 watt facility with an antenna HAAT of 68 meters via Hammond Ridge on Lake Road, about two miles from Millinocket Municipal Airport), ever since as long ago as late 2007, pending a planned permanent move to a 22,000 watt facility with an antenna HAAT of 198.4 meters (from just off Nicatou Road in Medway, well east of WSYY-FM's old or current transmitter tower location). On November 23th, 2016, the CP for this proposed move was modified to a 45,000 watt facility with an antenna HAAT of 146.7 meters; this is the first time this proposed move has ever received official approval from the FCC. WSYY-FM is one of the two Maine affiliates—apart from WLOB—of When Radio Was (7 days a week from 5:00AM through 6:00AM ET and also from 10:00PM through 11:00PM ET), is one of the two Maine affiliates—apart from WWMJ—of The Acoustic Storm (Saturdays from 9:00AM through 12:00PM ET), is Maine's only affiliate of the Crook & Chase syndicated Country Music countdown programming (Sunday afternoons from 2:00PM through 6:00PM ET), and is an affiliate of the Blues Deluxe radio show. WSYY-FM/WSYY-AM are unusual in that while these stations are authorized to broadcast 24 hours a day, the stations both have sign-offs every day (WSYY-AM signing off at sun-down and WSYY-FM broadcasting for approximately 18¼ hours per day, WSYY-FM's broadcast day concluding with the 11:00PM ET Top-of-the-Hour CBS Radio newscast and then a Nightly Sign-Off Announcement and then an instrumentation of the American national anthem, followed by Dead Air amidst a Transmitter Power-Down, not Signing Back Onto The Air until 4:55AM ET). In Old Town and also Bangor (and continuing southward and/or southwestward), the station has strong FM co-channel interference with Portland-market WHOM (which transmits from atop Mount Washington in New Hampshire, the tallest peak in the Northeast and had for a long time claimed on its website that it has the largest coverage area of any FM station in the USA, its signal spanning five states: NH, ME, VT, MA, NY and also parts of Southern Quebec Province, Canada), this matter being especially problematic before dawn or after dusk. In favorable atmospheric conditions, a very weak signal of WHOM can be DX-ed in Millinocket during overnight hours (when WSYY-FM is off-the-air).

text: WSYY-FM (94.9

text: FM

text: ) is a

text: radio station

text: broadcasting for approximately 18¼ hours per day (from 4:55AM through 11:10PM

text: ET

text: ), under the

text: slogan

text: , "Radio With An Attitude". Playing a mix of

text: Classic Hits

text: Adult Contemporary

text: Classic Rock

text: Oldies

text: Contemporary Pop Music

text: and

text: Today's Hot New Country

text: , the station broadcasts an

text: Adult Hits

text: Full-Service

text: format for approximately 16 hours per day, from 6:00AM through 10:00PM

text: ET

text: (reserving the first and, also, the final hour of their broadcast day to

text: When Radio Was

text: ). The Mountain 94.9 carries local high school sports in season. The Mountain 94.9 had also carried the complete schedule of

text: Red Sox Baseball

text: from 1997 through 2015

text: , prior to becoming a Former Affiliate in 2016, which was when

text: Millinocket

text: 's affiliation with the

text: Red Sox Baseball

text: would ultimately be transferred over to co-owned

text: WSYY-AM

text: , thus concluding the frequent interruptions to the music on The Mountain 94.9 during

text: Baseball

text: season). The station currently features programming from

text: CBS Radio

text: and carries

text: CBS Radio News

text: at the top of every hour (and has been an affiliate of that network for many decades). Licensed to

text: Millinocket, Maine

text: , USA, the station's broadcast signal serves the

text: Central Penobscot County

text: Eastern Piscataquis County

text: and

text: Southern Aroostook County

text: Maine

text: areas, and the station is licensed to service the town of

text: Millinocket, Maine

text: , the very town where its Studios/Offices and

text: Transmitter

text: Tower Site are all located within.  The station is currently owned by Katahdin Communications, Inc. WSYY-FM originally went on the air in 1978 on 97.7 FM as WKTR, upgrading to its current facilities in 1984 on 94.9. Prior to their The Mountain 94.9 branding, WSYY-FM used to be referred to as North Country 95, airing a full-time

text: Country Music

text: format. The current format, branding, and slogan was probably adopted around March 1, 2004, when Katahdin Communications, Inc. assumed control of WSYY-FM &

text: WSYY-AM

text: from Katahdin Timberlands, LLC (as a result of the radio station facing increasing land disputes), initially as a short term lease agreement but the transfer of ownership ultimately became permanent. Those same land disputes would eventually lead to a loss of WSYY-FM's 23,500

text: watt

text: transmitter location (featuring an antenna

text: HAAT

text: of 211 meters); as a result of this, WSYY-FM may have been operating under a

text: Special Temporary Authority

text: License (a 12,000

text: watt

text: facility with an antenna

text: HAAT

text: of 68 meters via Hammond Ridge on Lake Road, about two miles from Millinocket Municipal Airport), ever since as long ago as late 2007, pending a planned permanent move to a 22,000

text: watt

text: facility with an antenna

text: HAAT

text: of 198.4 meters (from just off Nicatou Road in

text: Medway

text: , well east of WSYY-FM's old or current

text: transmitter tower

text: location). On November 23th, 2016, the

text: CP

text: for this proposed move was modified to a 45,000

text: watt

text: facility with an antenna

text: HAAT

text: of 146.7 meters; this is the first time this proposed move has ever received official approval from the

text: FCC

text: . WSYY-FM is one of the two Maine affiliates—apart from

text: WLOB

text: —of

text: When Radio Was

text: (7 days a week from 5:00AM through 6:00AM

text: ET

text: and also from 10:00PM through 11:00PM

text: ET

text: ), is one of the two Maine affiliates—apart from

text: WWMJ

text: —of The Acoustic Storm (Saturdays from 9:00AM through 12:00PM

text: ET

text: ), is Maine's only affiliate of the

text: Crook & Chase

text: syndicated

text: Country Music

text: countdown programming (Sunday afternoons from 2:00PM through 6:00PM

text: ET

text: ), and is an affiliate of the Blues Deluxe radio show. WSYY-FM/

text: WSYY-AM

text: are unusual in that while these stations are authorized to broadcast 24 hours a day, the stations both have

text: sign-off

text: s every day (

text: WSYY-AM

text: signing off at

text: sun-down

text: and WSYY-FM broadcasting for approximately 18¼ hours per day, WSYY-FM's broadcast day concluding with the 11:00PM

text: ET

text: Top-of-the-Hour

text: CBS Radio

text: newscast and then a

text: Nightly Sign-Off Announcement

text: and then an

text: instrumentation

text: of the

text: American

text: national anthem

text: , followed by

text: Dead Air

text: amidst a

text: Transmitter

text: Power-Down, not

text: Signing Back Onto The Air

text: until 4:55AM

text: ET

text: ). In

text: Old Town

text: and also

text: Bangor

text: (and continuing southward and/or southwestward), the station has strong

text: FM

text: co-channel interference

text: with

text: Portland

text: -market

text: WHOM

text: (which transmits from atop

text: Mount Washington

text: in

text: New Hampshire

text: , the tallest peak in the Northeast and had for a long time claimed on its website that it has the largest coverage area of any

text: FM

text: station in the

text: USA

text: , its signal spanning five states:

text: NH

text: ME

text: VT

text: MA

text: NY

text: and also parts of

text: Southern Quebec

text: Province

text: Canada

text: ), this matter being especially problematic before

text: dawn

text: or after

text: dusk

text: . In favorable atmospheric conditions, a very weak signal of

text: WHOM

text: can be

text: DX-ed

text: in

text: Millinocket

text: during overnight hours (when WSYY-FM is off-the-air).

text: The station is currently owned by Beaver Dam-based Good Karma Broadcasting, LLC, and owned by Craig Karmazin, son of radio executive and former Sirius Satellite Radio CEO Mel Karmazin.  Craig Karmazin also owns several radio stations, including Jackson, WI (WAUK), Columbus, WI (WTTN-AM and WTLX-FM) and Beaver Dam, WI (WBEV-AM and WXRO-FM).  He owns two AM stations in Cleveland, OH, (WKNR-AM and WWGK-AM) and a partner in an AM-FM combo in West Palm Beach, Florida. (WUUB-FM and WEFL-AM)

text: The station is currently owned by

text: Beaver Dam

text: -based

text: Good Karma Broadcasting

text: , LLC, and owned by

text: Craig Karmazin

text: , son of radio executive and former

text: Sirius Satellite Radio

text: CEO

text: Mel Karmazin

text: .  Craig Karmazin also owns several radio stations, including Jackson, WI (WAUK), Columbus, WI (WTTN-AM and WTLX-FM) and Beaver Dam, WI (WBEV-AM and WXRO-FM).  He owns two AM stations in Cleveland, OH, (WKNR-AM and WWGK-AM) and a partner in an AM-FM combo in West Palm Beach, Florida. (WUUB-FM and WEFL-AM)

text: The city has three local radio stations. Radio Tay was launched on 17 October 1980. The station split frequencies in January 1995 launching Tay FM for a younger audience and Tay AM playing classic hits. In 1999, Discovery 102 was launched, later to be renamed Wave 102.

text: The city has three local radio stations. Radio Tay was launched on 17 October 1980. The station split frequencies in January 1995 launching

text: Tay FM

text: for a younger audience and

text: Tay AM

text: playing classic hits. In 1999, Discovery 102 was launched, later to be renamed

text: Wave 102

text: Most sources of light are classified as incoherent and unpolarized (or only "partially polarized") because they consist of a random mixture of waves having different spatial characteristics, frequencies (wavelengths), phases, and polarization states. However, for understanding electromagnetic waves and polarization in particular, it is easiest to just consider coherent plane waves; these are sinusoidal waves of one particular direction (or wavevector), frequency, phase, and polarization state. Characterizing an optical system in relation to a plane wave with those given parameters can then be used to predict its response to a more general case, since a wave with any specified spatial structure can be decomposed into a combination of plane waves (its so-called angular spectrum). And incoherent states can be modeled stochastically as a weighted combination of such uncorrelated waves with some distribution of frequencies (its spectrum), phases, and polarizations.

text: Most sources of light are classified as incoherent and unpolarized (or only "partially polarized") because they consist of a random mixture of waves having different spatial characteristics, frequencies (wavelengths), phases, and polarization states. However, for understanding electromagnetic waves and polarization in particular, it is easiest to just consider coherent plane waves; these are sinusoidal waves of one particular direction (or

text: wavevector

text: ), frequency, phase, and polarization state. Characterizing an optical system in relation to a plane wave with those given parameters can then be used to predict its response to a more general case, since a wave with any specified spatial structure can be decomposed into a combination of plane waves (its so-called

text: angular spectrum

text: ). And incoherent states can be modeled

text: stochastically

text: as a weighted combination of such uncorrelated waves with some

text: distribution

text: of frequencies (its

text: spectrum

text: ), phases, and polarizations.

text: This equation defines the wave functions and the energy spectrum within region (ii), while outsideof the region (ii), x<-a and x>a, the wave functions  are zero. The wave function

text: This equation defines the

text: wave functions

text: and the energy spectrum within region (ii), while outsideof the region (ii), x<-a and x>a, the wave functions  are zero. The wave function

text: The BBC began using FM sound broadcasting in 1955, but at that time AM sound broadcasting predominated. The BBC's 'popular music' station known as Radio 1 opened on AM in 1967 and left medium wave in 1994, but had been using FM full-time for six years previously, part-time before 1988. Currently, all but one of the BBC's analogue services, including Radios 1, 2, 3, and 4 and BBC Local Radio are provided on FM, although Radio 4 uses medium wave in some areas, long wave for national broadcasting; Local Radio broadcasts opt-outs on medium wave. The only analogue service not to use FM is Radio Five Live. BBC policy was to refer to FM as VHF on air until 30 September 1984 when FM became its official term.

text: The

text: BBC

text: began using FM sound broadcasting in 1955, but at that time

text: AM sound broadcasting

text: predominated. The BBC's 'popular music' station known as Radio 1 opened on AM in 1967 and left

text: medium wave

text: in 1994, but had been using FM full-time for six years previously, part-time before 1988. Currently, all but one of the BBC's analogue services, including

text: Radios 1

text: , and

text: and

text: BBC Local Radio

text: are provided on FM, although Radio 4 uses medium wave in some areas,

text: long wave

text: for national broadcasting; Local Radio broadcasts opt-outs on medium wave. The only analogue service not to use FM is

text: Radio Five Live

text: . BBC policy was to refer to FM as

text: VHF

text: on air until 30 September 1984 when FM became its official term.

text: Radio propagation is the behavior of radio waves as they travel, or are propagated, from one point to another, or into various parts of the atmosphere. As a form of electromagnetic radiation, like light waves, radio waves are affected by the phenomena of reflection, refraction, diffraction, absorption, polarization, and scattering.

text: Radio propagation is the behavior of

text: radio wave

text: s as they travel, or are

text: propagated

text: , from one point to another, or into various parts of the

text: atmosphere

text: . As a form of

text: electromagnetic radiation

text: , like light waves, radio waves are affected by the phenomena of

text: reflection

text: refraction

text: diffraction

text: absorption

text: polarization

text: , and

text: scattering

text: Radio Trent expanded transmission to neighbouring Derbyshire in 1987. Renamed Trent FM in 1988, it launched a separate oldies-format service, GEM-AM, on its medium wave frequencies. Its owners Midland Radio plc were taken over by the GWR Group in 1993, the Nottingham and Mansfield FM services were branded 96 Trent FM, while the Derby service became known as RAM FM. The medium wave GEM-AM service was then rebranded, to become Classic Gold GEM. By spring 2005, Trent found itself owned by GCap Media, after GWR Group's merger with Capital Radio Group. It became part of GCap's One Network brand, a network of FM and DAB music stations across southern England, the English Midlands and Wales. The station changed hands again in 2008 when Global Radio bought GCap Media.

text: Radio Trent expanded transmission to neighbouring Derbyshire in 1987. Renamed Trent FM in 1988, it launched a separate

text: oldies

text: -format service,

text: GEM-AM

text: , on its medium wave frequencies. Its owners

text: Midland Radio plc

text: were taken over by the

text: GWR Group

text: in 1993, the Nottingham and Mansfield FM services were branded 96 Trent FM, while the Derby service became known as

text: RAM FM

text: . The medium wave GEM-AM service was then rebranded, to become

text: Classic Gold GEM

text: . By spring 2005, Trent found itself owned by

text: GCap Media

text: , after

text: GWR Group

text: 's merger with

text: Capital Radio Group

text: . It became part of GCap's

text: One Network

text: brand, a network of FM and DAB music stations across southern England, the English Midlands and Wales. The station changed hands again in 2008 when

text: Global Radio

text: bought GCap Media.

text: Prior to switching to New Wave, the DWXB-FM management flirted with disco in the late 1970s and then adopted the American Top Forty format in 1982, dubbing itself as Cute 102. By 1983, WXB 102 started including New Wave acts from the UK into the Top 40 mix, due to the influence of the late DJ Mark Fournier and his Uncle Eric. In 1984, New Wave began erupting in Manila's dance clubs thanks to the city's mobile discos, who often spun records imported from Europe, and the proliferation of New Wave music videos on Philippine TV. WXB 102 gradually evolved into a New Wave radio station with the Fournier; The Unbeatable, the alias of Dave Ryan; and Rico Severino, known as J.J. Michaels. WXB 102 briefly competed with another New Wave and disco radio station in Manila, DZBM-FM 105.1 MHz (now DWBM-FM 105.1) which then dubbed as Power 105 BM FM (now 105.1 Crossover) in 1985.

text: Prior to switching to New Wave, the DWXB-FM management flirted with disco in the late 1970s and then adopted the American Top Forty format in 1982, dubbing itself as Cute 102. By 1983, WXB 102 started including New Wave acts from the

text: UK

text: into the

text: Top 40

text: mix, due to the influence of the late DJ Mark Fournier and his Uncle Eric. In 1984, New Wave began erupting in Manila's dance clubs thanks to the city's

text: mobile disco

text: s, who often spun records imported from Europe, and the proliferation of New Wave music videos on Philippine TV. WXB 102 gradually evolved into a New Wave radio station with the Fournier; The Unbeatable, the alias of Dave Ryan; and Rico Severino, known as J.J. Michaels. WXB 102 briefly competed with another New Wave and disco radio station in Manila, DZBM-FM 105.1 MHz (now DWBM-FM 105.1) which then dubbed as Power 105 BM FM (now

text: 105.1 Crossover

text: ) in 1985.

text: When the length of the wire segments are shorter than a quarter wavelength (λ/4) of the radio waves, as is typical for use below 1 MHz, the antenna functions as a vertical electrically short monopole antenna with capacitive top-loading.    Because the two horizontal arms of the "T" have equal but oppositely-directed currents in them, which causes the radio waves from them to cancel far from the antenna,  and because of similar cancelling ground currents, the horizontal wire radiates little radio power.   Instead it serves to add capacitance to the top of the antenna.           This increases the currents in the upper portion of the vertical wire (see drawing at right), increasing the radiation resistance and thus its efficiency, allowing it to radiate more power, or in a receiving antenna be more sensitive to incoming radio signals. The top load wire can increase radiated power by 2 to 4 times (3 to 6 dB) for a given base current.

text: When the length of the wire segments are shorter than a quarter

text: wavelength

text: (λ/4) of the radio waves, as is typical for use below 1 MHz, the antenna functions as a vertical

text: electrically short

text: monopole antenna

text: with capacitive top-loading.    Because the two horizontal arms of the "T" have equal but oppositely-directed currents in them, which causes the radio waves from them to cancel far from the antenna,  and because of similar cancelling ground currents, the horizontal wire radiates little radio power.   Instead it serves to add

text: capacitance

text: to the top of the antenna.           This increases the currents in the upper portion of the vertical wire (see drawing at right), increasing the

text: radiation resistance

text: and thus its efficiency, allowing it to radiate more power, or in a receiving antenna be more sensitive to incoming radio signals. The top load wire can increase radiated power by 2 to 4 times (3 to 6 dB) for a given base current.

text: In the history of radio communications, the term "detector" was first used for a device that detected the simple presence or absence of a radio signal, since all communications were in Morse code.  The term is still in use today to describe a component that extracts a particular signal from all of the electromagnetic waves present.  Detection is usually based on the frequency of the carrier signal, as in the familiar frequencies of radio broadcasting, but it may also involve filtering a faint signal from noise, as in radio astronomy, or reconstructing a hidden signal, as in steganography.

text: In the history of

text: radio

text: communications, the term "

text: detector

text: " was first used for a device that detected the simple presence or absence of a radio

text: signal

text: , since all communications were in

text: Morse code

text: .  The term is still in use today to describe a component that extracts a particular signal from all of the

text: electromagnetic waves

text: present.  Detection is usually based on the

text: frequency

text: of the

text: carrier signal

text: , as in the familiar frequencies of

text: radio broadcasting

text: , but it may also involve filtering a faint signal from

text: noise

text: , as in

text: radio astronomy

text: , or reconstructing a hidden signal, as in

text: steganography

text: In 2004, a second medium-wave transmitter with a power of 5 kW for transmitting the privately owned radio programme Truckradio was installed at Nordkirchen transmitter, which uses the same antenna as the transmitter of Deutschlandfunk.

text: In 2004, a second medium-wave transmitter with a power of 5 kW for transmitting the privately owned radio programme

text: Truckradio

text: was installed at Nordkirchen transmitter, which uses the same antenna as the transmitter of

text: Deutschlandfunk

text: With the publication of A Dynamical Theory of the Electromagnetic Field in 1865, Maxwell demonstrated that electric and magnetic fields travel through space as waves moving at the speed of light. Maxwell proposed that light is an undulation in the same medium that is the cause of electric and magnetic phenomena. The unification of light and electrical phenomena led to the prediction of the existence of radio waves.

text: With the publication of

entity_name: A Dynamical Theory of the Electromagnetic Field

text: A Dynamical Theory of the Electromagnetic Field

text: in 1865, Maxwell demonstrated that

text: electric

text: and

text: magnetic field

text: s travel through space as

text: waves

text: moving at the

text: speed of light

text: . Maxwell proposed that light is an undulation in the same medium that is the cause of electric and magnetic phenomena. The unification of light and electrical phenomena led to the prediction of the existence of

text: radio waves

text: Ionospheric HF pump facilities need to be sufficiently powerful to provide the possibility for plasma turbulence studies, although any radio wave that propagates in the ionosphere affects it by heating the electrons. That radio waves affect the ionosphere was discovered already in the 1930s with the Luxemburg effect. Although the research facilities need to have powerful transmitters, the power flux in the ionosphere for the most powerful facility (HAARP) is below 0.03 W/m. This gives an energy density in the ionosphere that is less than 1/100 of the thermal energy density of the ionospheric plasma itself. The power flux may also be compared with the solar flux at the Earth's surface of about 1.5 kW/m. During aurora generally no ionospheric effects can be observed with the HF pump facilities as the radio wave power is strongly absorbed by the naturally heated ionosphere.

text: Ionospheric HF pump facilities need to be sufficiently powerful to provide the possibility for plasma turbulence studies, although any radio wave that propagates in the ionosphere affects it by heating the electrons. That radio waves affect the ionosphere was discovered already in the 1930s with the

text: Luxemburg effect

text: . Although the research facilities need to have powerful transmitters, the power flux in the ionosphere for the most powerful facility (HAARP) is below 0.03 W/m. This gives an energy density in the ionosphere that is less than 1/100 of the thermal energy density of the ionospheric plasma itself. The power flux may also be compared with the solar flux at the Earth's surface of about 1.5 kW/m. During aurora generally no ionospheric effects can be observed with the HF pump facilities as the radio wave power is strongly absorbed by the naturally heated ionosphere.

text: On 1 March 1976, was also the year of the first outside television broadcast which was the coverage of His Majesty's birthday parade from the then 'Town Padang'. The television project was budgeted at B$35M. FM Stereo Radio Services from Brunei-Muara District started on 1 March 1977. At the same time, two high power Medium Wave stations at Brunei-Muara District commenced transmission of the Malay language service. RTB currently has 1000 staff. Coverage by radio and television is almost 100% of Brunei.

text: On 1 March 1976, was also the year of the first outside television broadcast which was the coverage of His Majesty's birthday parade from the then 'Town Padang'. The television project was budgeted at B$35M. FM Stereo Radio Services from Brunei-Muara District started on 1 March 1977. At the same time, two high power Medium Wave stations at Brunei-Muara District commenced transmission of the

text: Malay language

text: service. RTB currently has 1000 staff. Coverage by radio and television is almost 100% of Brunei.

text: The British Broadcasting Corporation BBC has trialed the technology in the United Kingdom by broadcasting BBC Radio Devon in the Plymouth area in the MF band. The trial lasted for a year (April 2007 – April 2008). The BBC also trialed DRM+ in the FM band in 2010 in the Fife area of Scotland, including the city of Edinburgh. In this trial, a previously used 10 kW (ERP) FM transmitter was replaced with a 1 kW DRM+ transmitter in two different modes and the coverage compared with FM   Digital Radio Mondiale was included in the 2007 Ofcom consultation on the future of radio in the United Kingdom for the AM medium wave band.

text: The British Broadcasting Corporation

text: BBC

text: has trialed the technology in the

text: United Kingdom

text: by broadcasting

text: BBC Radio Devon

text: in the Plymouth area in the MF band. The trial lasted for a year (April 2007 – April 2008). The

text: BBC

text: also trialed DRM+ in the FM band in 2010 in the Fife area of Scotland, including the city of Edinburgh. In this trial, a previously used 10 kW (ERP) FM transmitter was replaced with a 1 kW DRM+ transmitter in two different modes and the coverage compared with FM   Digital Radio Mondiale was included in the 2007

text: Ofcom

text: consultation on the future of radio in the

text: United Kingdom

text: for the AM medium wave band.

text: XHDI-FM/XEDI-AM is an AM/FM combo Spanish Contemporary Hit Radio radio station in Chihuahua, Chihuahua.

text: XHDI-FM/XEDI-AM is an AM/FM combo

text: Spanish Contemporary Hit Radio

text: radio station in

text: Chihuahua, Chihuahua

text: Though ubiquitous in early radio, the spark gap transmitter was finally doomed by its extremely broad frequency spectrum and damped wave output. Damped waves were excellent for radiotelegraph with early radio detectors, but are very wasteful of bandwidth. This limited the number of stations that could effectively use a band, because of the interference. Also, wide bandwidth meant the transmitter spread useful intelligence over a large spectrum, and only a fraction of the transmit power was useful for communications. Finally, the damped wave is already a form of amplitude modulation (AM) and cannot be further modulated for voice with any intelligibility. Only the continuous wave oscillators made possible by vacuum tube technology could provide high frequency (HF) and beyond, and only their advent made efficient radiotelegraph and voice/data transmissions possible.

text: Though ubiquitous in early radio, the spark gap transmitter was finally doomed by its extremely broad frequency spectrum and

text: damped wave

text: output. Damped waves were excellent for radiotelegraph with early radio detectors, but are very wasteful of

text: bandwidth

text: . This limited the number of stations that could effectively use a band, because of the interference. Also, wide bandwidth meant the transmitter spread useful intelligence over a large spectrum, and only a fraction of the transmit power was useful for communications. Finally, the damped wave is already a form of

text: amplitude modulation

text: (AM) and cannot be further modulated for voice with any intelligibility. Only the continuous wave oscillators made possible by vacuum tube technology could provide high frequency (HF) and beyond, and only their advent made efficient radiotelegraph and voice/data transmissions possible.

text: The Sun, the nearest star to Earth, is known to emit radio waves, though it is virtually the only regular star that has been detected in the radio spectrum, because it is so close. It is not considered a radio star because it is not a strong radio source.

text: The

text: Sun

text: , the nearest

text: star

text: to

text: Earth

text: , is known to emit radio waves, though it is virtually the only regular star that has been detected in the radio spectrum, because it is so close. It is not considered a radio star because it is not a strong radio source.

text: Greenleaf Whittier Pickard (February 14, 1877, Portland, Maine– January 8, 1956, Newton, Massachusetts) was a United States radio pioneer. Pickard was a researcher in the early days of wireless.  He was responsible for the development of the crystal detector, (cat's whisker detector),  a radio wave detector which was the central component in early radio receivers called crystal radios, which were the most widely used radio receivers until about 1920 and continued to be used until World War 2.   He also experimented with antennas, radio wave propagation, and noise suppression.On August 30, 1906 he filed a patent for a silicon crystal detector, which was granted on November 20, 1906. Pickard's detector was revolutionary in that he found that a fine pointed wire known as a "cat's whisker," in delicate contact with a mineral produced the best semiconductor effect. On June 10, 1907, he filed a patent for a Magnetic Aerial (a loop aerial) which was granted on January 21, 1908.  Pickard's loop antenna had directional properties that could be used to reduce interference to the intended wireless communications.  Greenleaf Whittier Pickard was named after his great-uncle, the American Quaker John Greenleaf Whittier (1807-1892). Pickard was president of the Institute of Radio Engineers in 1913.

text: Greenleaf Whittier Pickard (February 14, 1877,

text: Portland, Maine

text: – January 8, 1956,

text: Newton, Massachusetts

text: ) was a

text: United States

text: radio

text: pioneer. Pickard was a researcher in the early days of

text: wireless

text: .  He was responsible for the development of the

text: crystal detector

text: , (cat's whisker detector),  a radio wave detector which was the central component in early

text: radio receiver

text: s called

text: crystal radio

text: s, which were the most widely used radio receivers until about 1920 and continued to be used until World War 2.   He also experimented with

text: antennas

text: , radio wave propagation, and noise suppression.On August 30, 1906 he filed a patent for a

text: silicon

text: crystal

text: detector, which was granted on November 20, 1906. Pickard's detector was revolutionary in that he found that a fine pointed wire known as a "cat's whisker," in delicate contact with a mineral produced the best

text: semiconductor

text: effect. On June 10, 1907, he filed a patent for a Magnetic Aerial (a loop aerial) which was granted on January 21, 1908.  Pickard's loop antenna had directional properties that could be used to reduce interference to the intended wireless communications.  Greenleaf Whittier Pickard was named after his great-uncle, the American Quaker

text: John Greenleaf Whittier

text: (1807-1892). Pickard was president of the

text: Institute of Radio Engineers

text: in 1913.

text: Boston is the largest broadcasting market in New England, with the radio market being the 11th largest in the United States. Several major AM stations include talk radio WRKO, sports/talk station WEEI, and CBS Radio WBZ. WBZ (AM) broadcasts a news radio format. A variety of commercial FM radio formats serve the area, as do NPR stations WBUR and WGBH. College and university radio stations include WERS (Emerson), WHRB (Harvard), WUMB (UMass Boston), WMBR (MIT), WZBC (Boston College), WMFO (Tufts University), WBRS (Brandeis University), WTBU (Boston University, campus and web only), WRBB (Northeastern University) and WMLN-FM (Curry College).

text: Boston is the largest broadcasting market in New England, with the radio market being the 11th largest in the United States. Several major

text: AM

text: stations include

text: talk radio

text: WRKO

text: sports

text: /talk station

text: WEEI

text: , and

text: CBS Radio

text: WBZ

text: . WBZ (AM) broadcasts a

text: news radio

text: format. A variety of commercial

text: FM

text: radio format

text: s serve the area, as do

text: NPR

text: stations

text: WBUR

text: and

text: WGBH

text: . College and university radio stations include

text: WERS

text: (Emerson),

text: WHRB

text: (Harvard),

text: WUMB

text: (UMass Boston),

text: WMBR

text: (MIT),

text: WZBC

text: (Boston College),

text: WMFO

text: (Tufts University),

text: WBRS

text: (Brandeis University),

text: WTBU

text: (Boston University, campus and web only),

text: WRBB

text: (Northeastern University) and

text: WMLN-FM

text: (Curry College).

text: In the 1970s and early 1980s, as many listeners abandoned AM music formats for the high fidelity sound of FM radio, the talk radio format began to catch on in more large cities. Former music stations such as KLIF (Dallas, Texas), WLW (Cincinnati, Ohio), WHAS (Louisville, Kentucky), WHAM (Rochester, New York), WLS (Chicago, Illinois), KFI (Los Angeles, California), WRKO (Boston, Massachusetts), WKBW (Buffalo, New York), and WABC (New York, New York) made the switch to all-talk as their ratings slumped due to listener migration to the FM band. Since the turn of the 21st century, with many music listeners now migrating to digital music platforms such as Pandora Radio, Sirius XM Radio, and the numerous variations of the iPod, talk radio has been expanding on the FM side of the dial as well.

text: In the 1970s and early 1980s, as many listeners abandoned AM music formats for the

text: high fidelity

text: sound of

text: FM radio

text: , the talk radio format began to catch on in more large cities. Former music stations such as

text: KLIF

text: Dallas

text: Texas

text: WLW

text: Cincinnati, Ohio

text: WHAS

text: Louisville, Kentucky

text: WHAM

text: Rochester, New York

text: WLS

text: Chicago, Illinois

text: KFI

text: Los Angeles

text: California

text: WRKO

text: Boston

text: Massachusetts

text: WKBW

text: Buffalo, New York

text: ), and

text: WABC

text: New York, New York

text: ) made the switch to all-talk as their ratings slumped due to listener migration to the FM band. Since the turn of the 21st century, with many music listeners now migrating to digital music platforms such as

text: Pandora Radio

text: Sirius XM Radio

text: , and the numerous variations of the

text: iPod

text: , talk radio has been expanding on the FM side of the dial as well.

text: Early commercial and professional radio services relied exclusively on long wave, low frequencies and ground-wave propagation. To prevent interference with these services, amateur and experimental transmitters were restricted to the higher (HF) frequencies, felt to be useless since their ground-wave range was limited. Upon discovery of the other propagation modes possible at medium wave and short wave frequencies, the advantages of HF for commercial and military purposes became apparent. Amateur experimentation was then confined only to authorized frequency segments in that range.

text: Early commercial and professional radio services relied exclusively on

text: long wave

text: , low frequencies and ground-wave propagation. To prevent interference with these services, amateur and experimental transmitters were restricted to the higher (HF) frequencies, felt to be useless since their ground-wave range was limited. Upon discovery of the other propagation modes possible at

text: medium wave

text: and

text: short wave

text: frequencies, the advantages of HF for commercial and military purposes became apparent. Amateur experimentation was then confined only to authorized frequency segments in that range.

text: The development of radio links for sending telegraphs lead to the Wireless Telegraphy Act 1904, which granted control of radio waves to the General Post Office, who licensed all senders and receivers. This placed the Post Office in a position of control over radio and television broadcasting as those technologies were developed.

text: The development of radio links for sending telegraphs lead to the

text: Wireless Telegraphy Act 1904

text: , which granted control of radio waves to the General Post Office, who licensed all senders and receivers. This placed the Post Office in a position of control over radio and television broadcasting as those technologies were developed.

text: XHOX-FM/XEOX-AM is a combo AM/FM radio station in Ciudad Obregón, Sonora. Broadcasting on 1430 AM and 106.5 FM, the station is owned by Radio Grupo García de León and carries the national Exa FM format from MVS Radio.

text: XHOX-FM/XEOX-AM is a combo AM/FM radio station in

text: Ciudad Obregón, Sonora

text: . Broadcasting on

text: 1430 AM

text: and

text: 106.5 FM

text: , the station is owned by Radio Grupo García de León and carries the national

text: Exa FM

text: format from

text: MVS Radio

text: A horn antenna is used to transmit radio waves from a waveguide (a metal pipe used to carry radio waves) out into space, or collect radio waves into a waveguide for reception.  It typically consists of a short length of rectangular or cylindrical metal tube (the waveguide), closed at one end, flaring into an open-ended conical or pyramidal shaped horn on  the other end.  The radio waves are usually introduced into the waveguide by a coaxial cable attached to the side, with the central conductor projecting into the waveguide to form a quarter-wave monopole antenna.  The waves then radiate out the horn end in a narrow beam.  In some equipment the radio waves are conducted between the transmitter or receiver and the antenna by a waveguide; in this case the horn is attached to the end of the waveguide.  In outdoor horns, such as the feed horns of satellite dishes, the open mouth of the horn is often covered by a plastic sheet transparent to radio waves, to exclude moisture.

text: A horn antenna is used to transmit radio waves from a

text: waveguide

text: (a metal pipe used to carry radio waves) out into space, or collect radio waves into a waveguide for reception.  It typically consists of a short length of rectangular or cylindrical metal tube (the waveguide), closed at one end, flaring into an open-ended conical or pyramidal shaped horn on  the other end.  The radio waves are usually introduced into the waveguide by a

text: coaxial cable

text: attached to the side, with the central conductor projecting into the waveguide to form a

text: quarter-wave monopole

text: antenna.  The waves then radiate out the horn end in a narrow beam.  In some equipment the radio waves are conducted between the

text: transmitter

text: or

text: receiver

text: and the antenna by a waveguide; in this case the horn is attached to the end of the waveguide.  In outdoor horns, such as the

text: feed horn

text: s of satellite dishes, the open mouth of the horn is often covered by a plastic sheet transparent to radio waves, to exclude moisture.

text: While a square wave is constructed from only odd harmonics, a sawtooth wave's sound is harsh and clear and its spectrum contains both even and odd harmonics of the fundamental frequency. Because it contains all the integer harmonics, it is one of the best waveforms to use for subtractive synthesis of musical sounds, particularly bowed string instruments like violins and cellos, since the slip-stick behavior of the bow drives the strings with a sawtooth-like motion.

text: While a square wave is constructed from only odd harmonics, a sawtooth wave's sound is harsh and clear and its spectrum contains both even and odd

text: harmonic

text: s of the

text: fundamental frequency

text: . Because it contains all the integer harmonics, it is one of the best waveforms to use for

text: subtractive synthesis

text: of musical sounds, particularly bowed string instruments like violins and cellos, since the

text: slip-stick behavior

text: of the bow drives the strings with a sawtooth-like motion.

text: The AM radio problem of interference at night was addressed in a different way. At the time FM was set up, the available frequencies were far higher in the spectrum than those used for AM radio - by a factor of approximately 100. Using these frequencies meant that even at far higher power, the range of a given FM signal was much shorter; thus its market was more local than for AM radio. The reception range at night is the same as in the daytime. All FM broadcast transmissions are line-of-sight, and ionospheric bounce is not viable. The much larger bandwidths, compared to AM and SSB, are more susceptible to phase dispersion. Propagation speeds (celerities) are fastest in the ionosphere at the lowest sideband frequency. The celerity difference between the highest and lowest sidebands is quite apparent to the listener. Such distortion occurs up to frequencies of approximately 50 MHz. Higher frequencies do not reflect from the ionosphere, nor from storm clouds. Moon reflections have been used in some experiments, but require impractical power levels.

text: Penistone has its own radio station. Formed in 2005 Penistone FM operated a trial broadcast in September 2006 and successfully applied for a full-time licence. Penistone FM was renamed Penistone Community Radio/Penistone AM as the Community Radio Licence was initially awarded on the Medium Wave band; however, Ofcom cleared an FM frequency for the station. Penistone FM started test transmissions on 95.7 MHz FM on Saturday 9 May 2009 and officially launched on Saturday 6 June 2009, with its licence running for five years. The licence was renewed for a further five years, to finish in June 2019.

text: Penistone has its own radio station. Formed in 2005

text: Penistone FM

text: operated a trial broadcast in September 2006 and successfully applied for a full-time licence.

text: Penistone FM

text: was renamed Penistone Community Radio/Penistone AM as the Community Radio Licence was initially awarded on the Medium Wave band; however, Ofcom cleared an FM frequency for the station.

text: Penistone FM

text: started test transmissions on 95.7 MHz FM on Saturday 9 May 2009 and officially launched on Saturday 6 June 2009, with its licence running for five years. The licence was renewed for a further five years, to finish in June 2019.

text: East Wave Radio is a community-based radio station based in Lenasia, South Africa. It broadcasts on 92.2 FM .

text: East Wave Radio is a community-based radio station based in

text: Lenasia

text: South Africa

text: . It broadcasts on 92.2 FM .

text: Today, radio waves that are broadcast from thousands of stations, along with waves from other sources, fill the air around us continuously. Italy has three state-controlled radio networks that broadcast day and evening hours on both AM and FM. Program content varies from popular music to lectures, panel discussions, classical music, and opera, as well as frequent newscasts and feature reports. In addition, many private radio stations mix popular and classical music. A short-wave radio, though unnecessary, aids in reception of VOA, BBC, Vatican Radio in English and the Armed Forces Network in Germany and in other European stations.

text: Today, radio waves that are broadcast from thousands of stations, along with waves from other sources, fill the air around us continuously. Italy has three state-controlled radio networks that broadcast day and evening hours on both AM and FM. Program content varies from popular music to lectures, panel discussions, classical music, and opera, as well as frequent newscasts and feature reports. In addition, many private radio stations mix popular and classical music. A short-wave radio, though unnecessary, aids in reception of VOA, BBC,

text: Vatican Radio

text: in English and the Armed Forces Network in Germany and in other European stations.

text: An antenna amplifier boosts a radio signal considerably for devices that receive radio waves. Many devices have an RF amplifier stage in their circuitry, that amplifies the antenna signal, these include, but are not limited to; radios, televisions, mobile phones and Wi-Fi and Bluetooth devices. Amplifiers amplify everything, both the desired signal present at the antenna, and the noise. Typical signal noises include: ambient background noise (electric brush noise from electric motors, high voltage sources from, for example a gasoline engine ignition, or large dispersed currents in the vicinity of the desired reception electric fence). To add, consideration must be taken for the noise generated by the amplifier itself and all other electrical noise which may be generated by the device that is to receive a signal, for example a lot of consideration has to go into mobile phone circuitry design to eliminate as much noise from its own circuitry in order to not disturb the desired transmission signals from its own antenna(ae).

text: An antenna amplifier boosts a

text: radio signal

text: considerably for devices that receive

text: radio wave

text: s. Many devices have an

text: RF amplifier

text: stage in their circuitry, that amplifies the antenna signal, these include, but are not limited to; radios, televisions, mobile phones and Wi-Fi and Bluetooth devices. Amplifiers amplify everything, both the desired signal present at the antenna, and the noise. Typical signal noises include: ambient

text: background noise

text: (electric brush noise from electric motors, high voltage sources from, for example a gasoline

text: engine ignition

text: , or large dispersed currents in the vicinity of the desired reception

text: electric fence

text: ). To add, consideration must be taken for the noise generated by the amplifier itself and all other electrical noise which may be generated by the device that is to receive a signal, for example a lot of consideration has to go into mobile phone circuitry design to eliminate as much noise from its own circuitry in order to not disturb the desired transmission signals from its own antenna(ae).

text: There is a wide variety of radio stations serving the Pittsburgh market. The first was KDKA 1020 AM, also the world's first commercially licensed radio station, airing on November 2, 1920. Other popular stations include KQV 1410 AM (news), WBGG 970 AM (sports), KDKA-FM 93.7 FM (sports), WKST-FM 96.1 FM (pop and hip-hop), WAMO-AM 660 AM (hip-hop and R&B) WBZZ 100.7 FM (adult contemporary), WDVE 102.5 FM (album rock), WPGB 104.7 FM (talk), and WXDX 105.9 FM (modern rock). There are also three public radio stations in the area; including WESA 90.5 FM (National Public Radio affiliate), WQED 89.3 FM (classical), and WYEP 91.3 FM (adult alternative). Three non-commercial stations are run by Carnegie Mellon University (WRCT 88.3 FM), the University of Pittsburgh (WPTS 92.1 FM), and Point Park University (WPPJ 670 AM).

text: There is a wide variety of

text: radio stations

text: serving the Pittsburgh market. The first was

text: KDKA

text: 1020 AM, also the world's first commercially licensed radio station, airing on November 2, 1920. Other popular stations include

text: KQV

text: 1410 AM (news),

text: WBGG

text: 970 AM (sports),

text: KDKA-FM

text: 93.7 FM (sports),

text: WKST-FM

text: 96.1 FM (pop and hip-hop),

text: WAMO-AM

text: 660 AM (hip-hop and R&B)

text: WBZZ

text: 100.7 FM (adult contemporary),

text: WDVE

text: 102.5 FM (album rock),

text: WPGB

text: 104.7 FM (talk), and

text: WXDX

text: 105.9 FM (modern rock). There are also three

text: public radio stations

text: in the area; including

text: WESA

text: 90.5 FM (

text: National Public Radio

text: affiliate),

text: WQED

text: 89.3 FM (classical), and

text: WYEP

text: 91.3 FM (adult alternative). Three non-commercial stations are run by

text: Carnegie Mellon University

text: WRCT

text: 88.3 FM), the

text: University of Pittsburgh

text: WPTS

text: 92.1 FM), and

text: Point Park University

text: WPPJ

text: 670 AM).

text: Other stations in the Classic Hits group began as local commercial stations owned by the Government-owned Radio New Zealand, at a time when the New Zealand Government had a monopoly on the New Zealand radio market. In some regions, the station that would eventually become The Hits, was the only available radio station in that region. By the early 1990s, Radio New Zealand had switched most of their stations to FM but retained the stations original AM frequency for coverage in areas where the FM frequency could not be reached or for listeners with an AM only radio. The AM frequency was utilized for talkback and specialist shows in addition to the regular programming on the FM frequency. To cut costs and prepare the stations for commercial sale, Radio New Zealand began rebranding AM stations to Newstalk ZB and rebranding the FM stations as Classic Hits. The Classic Hits stations originally retained their heritage identity until 2009, and used a uniform green diamond logo until June 2011.

text: Other stations in the Classic Hits group began as local commercial stations owned by the Government-owned

text: Radio New Zealand

text: , at a time when the New Zealand Government had a monopoly on the New Zealand radio market. In some regions, the station that would eventually become The Hits, was the only available radio station in that region. By the early 1990s, Radio New Zealand had switched most of their stations to FM but retained the stations original AM frequency for coverage in areas where the FM frequency could not be reached or for listeners with an AM only radio. The AM frequency was utilized for talkback and specialist shows in addition to the regular programming on the FM frequency. To cut costs and prepare the stations for commercial sale, Radio New Zealand began rebranding AM stations to

text: Newstalk ZB

text: and rebranding the FM stations as Classic Hits. The Classic Hits stations originally retained their heritage identity until 2009, and used a uniform green diamond logo until June 2011.

text: By the 1920s, when amplification made television practical, Scottish inventor John Logie Baird employed the Nipkow disk in his prototype video systems. He created his prototype in a little village called Santa Cruz on the island of Trinidad where he was recovering from an illness. He had also started work on the first color television. On March 25, 1925, Baird gave the first public demonstration of televised silhouette images in motion, at Selfridge's Department Store in London. Since human faces had inadequate contrast to show up on his primitive system, he televised a ventriloquist's dummy named "Stooky Bill" talking and moving, whose painted face had higher contrast. By January 26, 1926 he demonstrated the transmission of an image of a face in motion by radio. This is widely regarded as the first television demonstration in history. The subject was Baird's business partner Oliver Hutchinson. Baird's system used the Nipkow disk for both scanning the image and displaying it. A bright light shining through a spinning Nipkow disk set with lenses projected a bright spot of light that swept across the subject. Selenium photoelectric tube detected the light reflected from the subject and converted it into a proportional electrical signal. This was transmitted by AM radio waves to a receiver unit, where the video signal was applied to a neon light behind a second Nipkow disk rotating synchronized with the first. The brightness of the neon lamp was varied in proportion to the brightness of each spot on the image. As each hole in the disk passed by, one scan line of the image was reproduced. Baird's disk had 30 holes, producing an image with only 30 scan lines, just enough to recognize a human face. In 1927, Baird transmitted a signal over  of telephone line between London and Glasgow. In 1928, Baird's company (Baird Television Development Company/Cinema Television) broadcast the first transatlantic television signal, between London and New York, and the first shore-to-ship transmission. In 1929, he became involved in the first experimental mechanical television service in Germany. In November of the same year, Baird and Bernard Natan of Pathé established France's first television company, Télévision-Baird-Natan. In 1931, he made the first outdoor remote broadcast, of the Epsom Derby. In 1932, he demonstrated ultra-short wave television. Baird's mechanical system reached a peak of 240-lines of resolution on BBC television broadcasts in 1936 though the mechanical system did not scan the televised scene directly. Instead a 17.5mm film was shot, rapidly developed and then scanned while the film was still wet.

text: By the 1920s, when amplification made television practical, Scottish inventor

text: John Logie Baird

text: employed the

text: Nipkow disk

text: in his prototype video systems. He created his prototype in a little village called Santa Cruz on the island of Trinidad where he was recovering from an illness. He had also started work on the first color television. On March 25, 1925, Baird gave the first public demonstration of televised

text: silhouette

text: images in motion, at

text: Selfridge's

text: Department Store in London. Since human faces had inadequate contrast to show up on his primitive system, he televised a ventriloquist's dummy named "Stooky Bill" talking and moving, whose painted face had higher contrast. By January 26, 1926 he demonstrated the transmission of an image of a face in motion by radio. This is widely regarded as the first television demonstration in history. The subject was Baird's business partner Oliver Hutchinson. Baird's system used the Nipkow disk for both scanning the image and displaying it. A bright light shining through a spinning Nipkow disk set with lenses projected a bright spot of light that swept across the subject. Selenium

text: photoelectric tube

text: detected the light reflected from the subject and converted it into a proportional electrical signal. This was transmitted by AM radio waves to a receiver unit, where the video signal was applied to a neon light behind a second Nipkow disk rotating synchronized with the first. The brightness of the neon lamp was varied in proportion to the brightness of each spot on the image. As each hole in the disk passed by, one

text: scan line

text: of the image was reproduced. Baird's disk had 30 holes, producing an image with only 30 scan lines, just enough to recognize a human face. In 1927, Baird transmitted a signal over  of telephone line between London and

text: Glasgow

text: . In 1928, Baird's company (Baird Television Development Company/Cinema Television) broadcast the first transatlantic television signal, between London and New York, and the first shore-to-ship transmission. In 1929, he became involved in the first experimental mechanical television service in Germany. In November of the same year, Baird and

text: Bernard Natan

text: of

text: Pathé

text: established France's first television company, Télévision-

text: Baird

text: -Natan. In 1931, he made the first outdoor remote broadcast, of the

text: Epsom Derby

text: . In 1932, he demonstrated

text: ultra-short wave

text: television. Baird's mechanical system reached a peak of 240-lines of resolution on

text: BBC

text: television broadcasts in 1936 though the mechanical system did not scan the televised scene directly. Instead a

text: 17.5mm film

text: was shot, rapidly developed and then scanned while the film was still wet.

text: The whole conflict between Indian and Pakistani television can be traced back to the mid-20th century. On 14 August 1947, Pakistan got its independence. Subsequently, from the 15th of August, Radio Pakistan Lahore became a hostile station. This rang alarm bells in New Delhi and since high-powered transmitters were unavailable in India, two low-powered 1-kilowatt medium-wave transmitters each were dispatched to Amritsar and Jalandhar. Thus, All India Radio Jalandhar-Amritsar came into existence. This arrangement continued for five years. Soon after independence the authorities in Pakistan increased the power of Lahore radio station from 10 kilowatts to 50 kilowatts. In 1953, All India Radio also installed a 50-kilowatt medium-wave transmitter at a place called Goraya, located equidistant from Ludhiana and Jalandhar. This arrangement continued until the 1990s. Pakistan added a 100-kilowatt medium-wave transmitter to its existing 50-kilowatt station in Lahore in 1965. India opened a 1-kilowatt medium-wave station at Chandigarh in 1965. Another radio station was to be opened at Amritsar, but due to the 1965 war with Pakistan, the idea was shelved. In the meanwhile, Radio Pakistan and Pakistan Television Service increased its presence in the border areas with India. Radio Pakistan then slowly and steadily kept opening new radio stations in the cities of Rawalpindi, Multan, Bahawalpur, Faisalabad, Mianwali, Islamabad and Sialkot. Pakistani television also dotted the entire border areas with Punjab, India with powerful transmitters. India started its second phase of expansion of broadcasting services in Punjab during the 1990s. During the 1990s, both the cities of Bathinda and Patiala possessed relay centers for Doordarshan and also got FM transmitters of All India Radio. The mother station at Jalandhar was upgraded with two high-powered medium-wave transmitters along with a 10-kilowatt FM transmitter. All India Radio Chandigarh was strengthened with a 10-kilowatt high-altitude transmitter at Kasauli, extending its range up to 110 miles radius. The construction of the Fazilka TV Tower followed in 1996 until its completion in 2007.

text: The whole conflict between Indian and Pakistani television can be traced back to the mid-20th century. On 14 August 1947, Pakistan got its independence. Subsequently, from the 15th of August, Radio Pakistan Lahore became a hostile station. This rang alarm bells in

text: New Delhi

text: and since high-powered transmitters were unavailable in India, two low-powered 1-kilowatt medium-wave transmitters each were dispatched to Amritsar and Jalandhar. Thus, All India Radio Jalandhar-Amritsar came into existence. This arrangement continued for five years. Soon after independence the authorities in Pakistan increased the power of Lahore radio station from 10 kilowatts to 50 kilowatts. In 1953, All India Radio also installed a 50-kilowatt medium-wave transmitter at a place called Goraya, located equidistant from Ludhiana and Jalandhar. This arrangement continued until the 1990s. Pakistan added a 100-kilowatt medium-wave transmitter to its existing 50-kilowatt station in Lahore in 1965. India opened a 1-kilowatt medium-wave station at Chandigarh in 1965. Another radio station was to be opened at Amritsar, but due to the

text: 1965 war with Pakistan

text: , the idea was shelved. In the meanwhile, Radio Pakistan and Pakistan Television Service increased its presence in the border areas with India. Radio Pakistan then slowly and steadily kept opening new radio stations in the cities of

text: Rawalpindi

text: Multan

text: Bahawalpur

text: Faisalabad

text: Mianwali

text: Islamabad

text: and

text: Sialkot

text: . Pakistani television also dotted the entire border areas with

text: Punjab, India

text: with powerful transmitters. India started its second phase of expansion of broadcasting services in Punjab during the 1990s. During the 1990s, both the cities of

text: Bathinda

text: and

text: Patiala

text: possessed relay centers for Doordarshan and also got FM transmitters of All India Radio. The mother station at Jalandhar was upgraded with two high-powered medium-wave transmitters along with a 10-kilowatt FM transmitter. All India Radio Chandigarh was strengthened with a 10-kilowatt high-altitude transmitter at Kasauli, extending its range up to 110 miles radius. The construction of the Fazilka TV Tower followed in 1996 until its completion in 2007.

text: At the end of World War II he became a pioneer of the new science of radio astronomy, his interest being stirred by the discovery of radio waves from the Galaxy and by reports of intense interference in metre-wave radar receivers caused by disturbances on the Sun. To investigate the latter Pawsey, with Ruby Payne-Scott and Lindsay McCready, used an existing Royal Australian Air Force antenna at Collaroy, a northern Sydney suburb. In addition to confirming that the Sun was a source of radio noise their data also showed that the temperature in some regions of the Sun were as high as one million degrees. This temperature was far higher than was thought possible at the time. Work by the physicist David Forbes Martyn showed that temperatures peak in the Sun's corona at one million degrees. The observations with the Collaroy antenna not only marked the beginning of radio astronomy in Australia, but also the first time radio astronomy had provided important information on a problem in traditional optical astronomy.

text: At the end of

text: World War II

text: he became a pioneer of the new science of

text: radio astronomy

text: , his interest being stirred by the discovery of radio waves from the

text: Galaxy

text: and by reports of intense interference in metre-wave radar receivers caused by disturbances on the

text: Sun

text: . To investigate the latter Pawsey, with

text: Ruby Payne-Scott

text: and Lindsay McCready, used an existing

text: Royal Australian Air Force

text: antenna at

text: Collaroy

text: , a northern

text: Sydney

text: suburb. In addition to confirming that the Sun was a source of

text: radio noise

text: their data also showed that the temperature in some regions of the Sun were as high as one million degrees. This temperature was far higher than was thought possible at the time. Work by the physicist

text: David Forbes Martyn

text: showed that temperatures peak in the Sun's

text: corona

text: at one million degrees. The observations with the Collaroy antenna not only marked the beginning of radio astronomy in Australia, but also the first time radio astronomy had provided important information on a problem in traditional optical astronomy.

text: High frequency (HF) is the ITU designation for the range of radio frequency electromagnetic waves (radio waves) between 3 and 30 MHz. It is also known as the decameter band or decameter wave as its wavelengths range from one to ten decameters (ten to one hundred metres). Frequencies immediately below HF are denoted medium frequency (MF), while the next band of higher frequencies is known as the very high frequency (VHF) band. The HF band is a major part of the shortwave band of frequencies, so communication at these frequencies is often called shortwave radio.  Because radio waves in this band can be reflected back to Earth by the ionosphere layer in the atmosphere – a method known as "skip" or "skywave" propagation – these frequencies are suitable for long-distance communication across intercontinental distances. The band is used by international shortwave broadcasting stations (2.310 - 25.820 MHz), aviation communication, government time stations, weather stations, amateur radio and citizens band services, among other uses.

text: High frequency (HF) is the

text: ITU

text: designation for the range of

text: radio frequency

text: electromagnetic wave

text: s (radio waves) between 3 and 30

text: MHz

text: . It is also known as the decameter band or decameter wave as its wavelengths range from one to ten

text: decameters

text: (ten to one hundred metres). Frequencies immediately below HF are denoted

text: medium frequency

text: (MF), while the next band of higher frequencies is known as the

text: very high frequency

text: (VHF) band. The HF band is a major part of the

text: shortwave

text: band of frequencies, so communication at these frequencies is often called

text: shortwave radio

text: .  Because radio waves in this band can be reflected back to Earth by the

text: ionosphere

text: layer in the atmosphere – a method known as "skip" or "

text: skywave

text: " propagation – these frequencies are suitable for long-distance communication across intercontinental distances. The band is used by international shortwave broadcasting stations (2.310 - 25.820 MHz), aviation communication, government time stations, weather stations,

text: amateur radio

text: and

text: citizens band

text: services, among other uses.

text: He worked in several domestic and foreign magazines, for example as a member of the editorial board of Orient Express (Oxford, UK) and World Haiku (Kyoto, Japan). He wrote screenplays for film, theatre, TV shows, radio dramas and comic books. His works were translated in English, French, Italian, Japanese, Russian, Polish, Hungarian, Czech, Slovak and other languages.	Aleksandar Prokopiev was also an active musician. While studying in Belgrade he played with the Yugoslav rock band Idoli, an eminent act of the former Yugoslav new wave scene. It is claimed that he wrote the famous Idoli's song Retko te viđam sa devojkama, however he is not credited on the record itself (Vlada Divljan is credited as the author instead). In Macedonia, Prokopiev was a member of the notable band Usta na Usta which was active during the 1980s. Its recordings were released by the music production branch of the national Macedonian Radio-Television.

text: He worked in several domestic and foreign magazines, for example as a member of the

text: editorial board

text: of Orient Express (

text: Oxford

text: , UK) and World Haiku (

text: Kyoto

text: , Japan). He wrote screenplays for film, theatre, TV shows,

text: radio drama

text: s and comic books. His works were translated in English, French, Italian, Japanese, Russian,

text: Polish

text: Hungarian

text: Czech

text: Slovak

text: and other languages.	Aleksandar Prokopiev was also an active musician. While studying in Belgrade he played with the

entity_name: Popular music in the Socialist Federal Republic of Yugoslavia

text: Yugoslav rock

text: band

text: Idoli

text: , an eminent act of the former

text: Yugoslav new wave scene

text: . It is claimed that he wrote the famous Idoli's song

text: Retko te viđam sa devojkama

text: , however he is not credited on the record itself (

text: Vlada Divljan

text: is credited as the author instead). In Macedonia, Prokopiev was a member of the notable band Usta na Usta which was active during the 1980s. Its recordings were released by the music production branch of the national

text: Macedonian Radio-Television

text: is the four-wave-number.  If it were possible to design a spectrum analyzer in four dimensions, then one could generalize the idea of switching back and forth between the time domain and the frequency domain.  Instead, one would switch between the spacetime domain and the energy-momentum domain.  This  carries over to general relativity as well.  The most user-friendly version of this theory is called Schwarzschild spacetime.  In that case, the Fourier transform is defined also, as long as one stays outside of the photon sphere.  The frequency decreases as one climbs up out of the potential well, and therefore one may define a Schwarzschild four-wave-number S.  Therefore, the transformer becomes

text: is the

text: four-wave-number

text: .  If it were possible to design a

text: spectrum analyzer

text: in four dimensions, then one could generalize the idea of switching back and forth between the

text: time domain

text: and the

text: frequency domain

text: .  Instead, one would switch between the

text: spacetime

text: domain and the

text: energy-momentum

text: domain.  This  carries over to

text: general relativity

text: as well.  The most user-friendly version of this theory is called

text: Schwarzschild spacetime

text: .  In that case, the Fourier transform is defined also, as long as one stays outside of the

text: photon sphere

text: .  The frequency decreases as one climbs up out of the potential well, and therefore one may define a Schwarzschild four-wave-number S.  Therefore, the transformer becomes

text: In the 1990s, many of the CBC's AM stations moved to FM in response to complaints of poor AM reception.  This meant that the old distinction between the AM "Radio" network and the FM "Stereo" network was no longer accurate, even though many of the FM "Radio" stations broadcast in mono only. As a result, in 1997 CBC Radio became CBC Radio One and CBC Stereo became CBC Radio 2. Although some Radio One stations still broadcast on AM as of 2016, because of issues with urban reception of AM radio signals many of the remaining AM stations have added FM rebroadcasters in major urban centres within their broadcast area.

text: In the 1990s, many of the CBC's

entity_name: List of defunct CBC radio transmitters in Canada

text: AM stations moved to FM

text: in response to complaints of poor AM reception.  This meant that the old distinction between the AM "Radio" network and the FM "Stereo" network was no longer accurate, even though many of the FM "Radio" stations broadcast in mono only. As a result, in 1997 CBC Radio became CBC Radio One and CBC Stereo became

text: CBC Radio 2

text: . Although some Radio One stations still broadcast on AM as of 2016, because of issues with urban reception of AM radio signals many of the remaining AM stations have added FM rebroadcasters in major urban centres within their broadcast area.

text: . Some wave height spectra are listed below. The dimension of the wave spectrum is

text: Radio Waves is a radio station in Bhutan. It is currently being run by Kelzang Thinley. It is located in Thimphu, just below Chubachu. The languages used by Radio Waves are Dzongkha and English. The frequency of Radio waves is 88.8 and it was formed in December 10, 2010.

text: Radio Waves is a radio station in

text: Bhutan

text: . It is currently being run by Kelzang Thinley. It is located in

text: Thimphu

text: , just below Chubachu. The languages used by Radio Waves are

text: Dzongkha

text: and English. The frequency of Radio waves is 88.8 and it was formed in December 10, 2010.

text: Since the lens is in the far field of any PSF spot, the field incident on the lens from the spot may be regarded as being a spherical wave, as in eqn. (2.2), not as a plane wave spectrum, as in eqn. (2.1). On the other hand, the lens is in the near field of the entire input plane transparency, therefore eqn. (2.1) - the full plane wave spectrum - accurately represents the field incident on the lens from that larger, extended source.

text: Polarization is the sum of the E-plane orientations over time projected onto an imaginary plane perpendicular to the direction of motion of the radio wave. In the most general case, polarization is elliptical, meaning that the polarization of the radio waves varies over time. Two special cases are linear polarization (the ellipse collapses into a line) as we have discussed above, and circular polarization (in which the two axes of the ellipse are equal). In linear polarization the electric field of the radio wave oscillates back and forth along one direction; this can be affected by the mounting of the antenna but usually the desired direction is either horizontal or vertical polarization. In circular polarization, the electric field (and magnetic field) of the radio wave rotates at the radio frequency circularly around the axis of propagation. Circular or elliptically polarized radio waves are designated as right-handed or left-handed using the "thumb in the direction of the propagation" rule. Note that for circular polarization, optical researchers use the opposite right hand rule from the one used by radio engineers.

text: Polarization is the sum of the E-plane orientations over time projected onto an imaginary plane perpendicular to the direction of motion of the radio wave. In the most general case, polarization is

text: elliptical

text: , meaning that the polarization of the radio waves varies over time. Two special cases are

text: linear polarization

text: (the ellipse collapses into a line) as we have discussed above, and

text: circular polarization

text: (in which the two axes of the ellipse are equal). In linear polarization the electric field of the radio wave oscillates back and forth along one direction; this can be affected by the mounting of the antenna but usually the desired direction is either horizontal or vertical polarization. In circular polarization, the electric field (and magnetic field) of the radio wave rotates at the radio frequency circularly around the axis of propagation. Circular or elliptically polarized radio waves are

text: designated as right-handed or left-handed

text: using the "thumb in the direction of the propagation" rule. Note that for circular polarization, optical researchers use the opposite

text: right hand rule

text: from the one used by radio engineers.

text: Cookeville is also served by nine FM and three AM radio stations. Tennessee Tech University's campus radio station operates at WTTU 88.5 FM, and National Public Radio (NPR) broadcasts at WHRS 91.7 FM (simulcast with WPLN, Nashville). Rock and roll and Top 40 stations include WBXE 93.7 FM and WKSW 98.5 Kiss FM, and country music can be found at WGSQ 94.7 FM Country Giant and WKXD-FM 106.9 Kicks FM. There is also one easy listening station at WLQK 95.9 FM and two Christian music stations: WAYM 90.5 FM Christian Hit Radio and WWOG 90.9 FM. There are three talk radio stations broadcasting on the AM dial: WPTN AM 780 (sports), WHUB AM 1400 (news) and WATX 1600 AM (news).

text: Cookeville is also served by nine

text: FM

text: and three

text: AM

text: radio station

text: s. Tennessee Tech University's

text: campus radio

text: station operates at

text: WTTU

text: 88.5 FM, and

text: National Public Radio

text: (NPR) broadcasts at

text: WHRS

text: 91.7 FM (simulcast with

text: WPLN

text: , Nashville).

text: Rock and roll

text: and

text: Top 40

text: stations include

text: WBXE

text: 93.7 FM and

text: WKSW

text: 98.5 Kiss FM, and

text: country music

text: can be found at

text: WGSQ

text: 94.7 FM Country Giant and

text: WKXD-FM

text: 106.9 Kicks FM. There is also one

text: easy listening

text: station at

text: WLQK

text: 95.9 FM and two

text: Christian music

text: stations:

text: WAYM

text: 90.5 FM Christian Hit Radio and

text: WWOG

text: 90.9 FM. There are three

text: talk radio

text: stations broadcasting on the AM dial:

text: WPTN

text: AM 780 (sports),

text: WHUB

text: AM 1400 (news) and

text: WATX

text: 1600 AM (news).

text: All of these waves, from the lowest-frequency radio waves to the highest-frequency gamma rays, are fundamentally the same, and they are all called electromagnetic radiation. They all travel through a vacuum at the same speed (the speed of light), giving them wavelengths inversely proportional to their frequencies.

text: All of these waves, from the lowest-frequency radio waves to the highest-frequency gamma rays, are fundamentally the same, and they are all called

text: electromagnetic radiation

text: . They all travel through a vacuum at the same speed (the

text: speed of light

text: ), giving them

text: wavelength

text: s inversely proportional to their frequencies.

text: AM broadcasting is the process of radio broadcasting using amplitude modulation (AM). AM was the first method of impressing sound on a radio signal and is still widely used today. Commercial and public AM broadcasting is authorized in the medium wave band worldwide, and also in parts of the longwave and shortwave bands. Radio broadcasting was made possible by the invention of the amplifying vacuum tube, the Audion (triode), by Lee de Forest in 1906, which led to the development of inexpensive vacuum tube AM radio receivers and transmitters during World War I. Commercial AM broadcasting developed from amateur broadcasts around 1920, and was the only commercially important form of radio broadcasting until FM broadcasting began after World War II. This period is known as the "Golden Age of Radio". Today, AM competes with FM, as well as with various digital radio broadcasting services distributed from terrestrial and satellite transmitters.  In many countries the narrow audio bandwidth (lower audio fidelity) and higher levels of interference experienced with AM transmission have led AM broadcasters to specialise in spoken-word programming such as news, sports and talk radio, leaving transmission of music mainly to FM and digital broadcasters.

text: AM broadcasting is the process of

text: radio broadcasting

text: using

text: amplitude modulation

text: (AM). AM was the first method of impressing sound on a radio signal and is still widely used today. Commercial and public AM broadcasting is authorized in the

text: medium wave

text: band worldwide, and also in parts of the

text: longwave

text: and

text: shortwave

text: bands. Radio broadcasting was made possible by the invention of the amplifying

text: vacuum tube

text: , the

text: Audion

text: triode

text: ), by

text: Lee de Forest

text: in 1906, which led to the development of inexpensive vacuum tube AM

text: radio receiver

text: s and

text: transmitter

text: s during World War I. Commercial AM broadcasting developed from amateur broadcasts around 1920, and was the only commercially important form of radio broadcasting until

text: FM broadcasting

text: began after World War II. This period is known as the "

text: Golden Age of Radio

text: ". Today, AM competes with FM, as well as with various

text: digital radio

text: broadcasting services distributed from terrestrial and satellite transmitters.  In many countries the narrow audio bandwidth (lower audio fidelity) and higher levels of

text: interference

text: experienced with AM transmission have led AM broadcasters to specialise in spoken-word programming such as

text: news

text: sports

text: and

text: talk radio

text: , leaving transmission of music mainly to FM and digital broadcasters.

text: Around 1995, J-WAVE hired new personalities in an attempt to rejuvenate itself. Its term "J-POP" became synonymous with commercially palatable Japanese music from across the spectrum, except for traditional Japanese music. Specials started to air around this time, and the station took steps to attract a listener base desirable for higher ad revenues.The format J-WAVE introduced to Japan, "more music less talk" almost disappeared during reorganization in early 1997, when DJ banter became more pronounced.

text: To promote the album, Folks appeared on many Hokkaido-based radio stations such as FM North Wave, Air-G', STV Radio and HBC Radio. They were also interviewed for music magazine Musica.

text: He is a regular presenter of Night Waves on BBC Radio 3.

text: He is a regular presenter of

text: Night Waves

text: on

text: BBC Radio 3

text: Cable television is a system of delivering television programming to paying subscribers via radio frequency (RF) signals transmitted through coaxial cables or, in the 2010s, light pulses through fiber-optic cables. This contrasts with broadcast television, in which the television signal is transmitted over the air by radio waves and received by a television antenna attached to the television. FM radio programming, high-speed Internet, telephone services, and similar non-television services may also be provided through these cables.Analog television was standard in the 20th century, but since the 2000s, cable systems have been upgraded to digital cable operation.

text: Cable television is a system of delivering

text: television programming

text: to paying subscribers via

text: radio frequency

text: (RF) signals transmitted through

text: coaxial cable

text: s or, in the 2010s, light pulses through

text: fiber-optic cable

text: s. This contrasts with

text: broadcast television

text: , in which the television signal is transmitted over the air by

text: radio wave

text: s and received by a

text: television antenna

text: attached to the television.

text: FM radio

text: programming,

text: high-speed Internet

text: telephone service

text: s, and similar non-television services may also be provided through these cables.

text: Analog television

text: was standard in the 20th century, but since the 2000s, cable systems have been upgraded to

text: digital cable

text: operation.

text: The Malawi Broadcasting Corporation is a state-run radio company in Malawi. It was founded in 1964. It has two radio stations, Radio 1 and Radio 2, and transmits on FM, Medium Wave and Shortwave frequencies and Online.

text: The Malawi Broadcasting Corporation is a state-run radio company in

text: Malawi

text: . It was founded in 1964. It has two

text: radio station

text: s, Radio 1 and Radio 2, and transmits on

text: FM

text: Medium Wave

text: and

text: Shortwave

text: frequencies and Online.

text: The elements are given the correct lengths and spacings so that the radio waves radiated by the driven element and those reradiated by the parasitic elements all arrive at the front of the antenna in phase, so they superpose and add, increasing signal strength in the forward direction.   In other words, the crest of the forward wave from the reflector element reaches the driven element just as the crest of the wave is emitted from that element.  These waves reach the first director element just as the crest of the wave is emitted from that element, and so on.  The waves in the reverse direction interfere destructively, cancelling out, so the signal strength radiated in the reverse direction is small.  Thus the antenna radiates a unidirectional beam of radio waves from the front (director end) of the antenna.

text: The elements are given the correct lengths and spacings so that the radio waves radiated by the driven element and those reradiated by the parasitic elements all arrive at the front of the antenna in phase, so they superpose and add, increasing signal strength in the forward direction.   In other words, the crest of the forward wave from the reflector element reaches the driven element just as the crest of the wave is emitted from that element.  These waves reach the first director element just as the crest of the wave is emitted from that element, and so on.  The waves in the reverse direction

text: interfere destructively

text: , cancelling out, so the signal strength radiated in the reverse direction is small.  Thus the antenna radiates a unidirectional beam of radio waves from the front (director end) of the antenna.

text: There are sixteen radio stations in Mumbai, twelve of which broadcast in the frequency modulation (FM) band. Two of these are broadcast by All India Radio. Navi Mumbai is also covered by these stations. Three stations, all run by AIR, broadcast on the amplitude modulation (AM) medium wave (MW) band. One broadcasts on the AM short wave (SW) band, which is also an AIR station. There are also a few internet-based radio shows starting up in the city.  These include Tiffin Talk, a show that describes itself as "a new radio project in Mumbai with the simple goal of delivering relevant discussion."  It is a weekly show focusing on political, business, and cultural issues that distributes as a podcast.  There is also TD Radio, a show created by Teen Diaries LLC, that focuses on teen issues in the city.  It airs live via webcast.

text: There are sixteen

text: radio

text: stations in

text: Mumbai

text: , twelve of which broadcast in the

text: frequency modulation

text: (FM) band. Two of these are broadcast by All India Radio. Navi Mumbai is also covered by these stations. Three stations, all run by

text: AIR

text: , broadcast on the

text: amplitude modulation

text: (AM)

text: medium wave

text: (MW) band. One broadcasts on the AM

text: short wave

text: (SW) band, which is also an AIR station. There are also a few internet-based radio shows starting up in the city.  These include Tiffin Talk, a show that describes itself as "a new radio project in Mumbai with the simple goal of delivering relevant discussion."  It is a weekly show focusing on political, business, and cultural issues that distributes as a podcast.  There is also TD Radio, a show created by Teen Diaries LLC, that focuses on teen issues in the city.  It airs live via webcast.

text: In February 2003 Talpa Radio International brought an enterprise of John de Mol, Radio 10 FM. Some sources claim that already Talpa's intention was to change the name back, but there is no further support available. Among the innovations that went through the station, included the return of Ferry Maat and strengthening by Bart van Leeuwen. A revised program and a new logo seen on May 5 that year was born. The greatest challenge facing the organization has faced that period, was to maintain the FM frequency. FM means a greater range of listeners than AM (medium wave) and thus higher advertising revenues. To no avail: just a few weeks after the start of the innovations Talpa lost "103 FM" (aka lot A3) on Sky Radio during the auction of terrestrial frequencies to it on June 1 started using for "Radio 103" . With the loss of the FM Radio frequency was 10 acute financial problems. Initially there was talk of Sky Radio transmitter and employees of Talpa over would take, but the merger fell through. Talpa had substantial cut in the workforce and Radio 10 was forced to move into the studios of sister station Noordzee FM. Exactly a month after the loss of 103 FM could Talpa Radio 10 ("gold" instead of "FM") hire an AM frequency of the former owner. Radio 10 Gold would use this wavelength to August 1, 2004.

text: In February 2003 Talpa Radio International brought an enterprise of

text: John de Mol

text: , Radio 10 FM. Some sources claim that already Talpa's intention was to change the name back, but there is no further support available. Among the innovations that went through the station, included the return of Ferry Maat and strengthening by

text: Bart van Leeuwen

text: . A revised program and a new logo seen on May 5 that year was born. The greatest challenge facing the organization has faced that period, was to maintain the FM frequency. FM means a greater range of listeners than AM (medium wave) and thus higher advertising revenues. To no avail: just a few weeks after the start of the innovations Talpa lost "103 FM" (aka lot A3) on

text: Sky Radio

text: during the auction of terrestrial frequencies to it on June 1 started using for "Radio 103" . With the loss of the FM Radio frequency was 10 acute financial problems. Initially there was talk of Sky Radio transmitter and employees of Talpa over would take, but the merger fell through. Talpa had substantial cut in the workforce and Radio 10 was forced to move into the studios of sister station

text: Noordzee FM

text: . Exactly a month after the loss of 103 FM could Talpa Radio 10 ("gold" instead of "FM") hire an AM frequency of the former owner. Radio 10 Gold would use this wavelength to August 1, 2004.

text: As television made waves around the nation, radio stations like WMAQ shifted to recorded music. For many years due to union constraints, all music broadcast on the network was live; stations had to maintain full-time orchestras on their payrolls. The organ music which was a part of many of the radio "soap operas" was provided by union musicians. When turntables entered studio control rooms, the musicians were replaced by the turntable operator or "record turner". It was the job of the turntable operator (a member of the American Federation of Musicians), to play any recorded music. The Musician's Union received jurisdiction over the turntables because it was reasoned that each turntable was responsible for five "live" musicians losing their employment. Not until the late 1960s did the union turntable operator leave the control rooms of NBC, Chicago.

text: As television made waves around the nation, radio stations like WMAQ shifted to recorded music. For many years due to union constraints, all music broadcast on the network was live; stations had to maintain full-time orchestras on their payrolls. The organ music which was a part of many of the radio "soap operas" was provided by union musicians. When turntables entered studio control rooms, the musicians were replaced by the turntable operator or "record turner". It was the job of the turntable operator (a member of the

text: American Federation of Musicians

text: ), to play any recorded music. The Musician's Union received jurisdiction over the turntables because it was reasoned that each turntable was responsible for five "live" musicians losing their employment. Not until the late 1960s did the union turntable operator leave the control rooms of NBC, Chicago.

text: Radio frequencies occupy the range from a 3 kHz to 300 GHz, although commercially important uses of radio use only a small part of this spectrum. Other types of electromagnetic radiation, with frequencies above the RF range, are infrared, visible light, ultraviolet, X-rays and gamma rays. Since the energy of an individual photon of radio frequency is too low to remove an electron from an atom, radio waves are classified as non-ionizing radiation.

text: Radio frequencies occupy the range from a 3 kHz to 300 GHz, although commercially important uses of radio use only a small part of this spectrum. Other types of electromagnetic radiation, with frequencies above the RF range, are

text: infrared

text: , visible

text: light

text: ultraviolet

text: X-ray

text: s and

text: gamma ray

text: s. Since the energy of an individual

text: photon

text: of radio frequency is too low to remove an

text: electron

text: from an

text: atom

text: , radio waves are classified as

text: non-ionizing radiation

text: By the 1920s when amplification made television practical, Scottish inventor John Logie Baird employed the Nipkow disk in his prototype video systems. On March 25, 1925, Baird gave the first public demonstration of televised silhouette images in motion, at Selfridge's Department Store in London.  Since human faces had inadequate contrast to show up on his primitive system, he televised a ventriloquist's dummy named "Stooky Bill" talking and moving, whose painted face had higher contrast. By January 26, 1926, he demonstrated the transmission of image of a face in motion by radio. This is widely regarded as first television demonstration. Baird's system used the Nipkow disk for both scanning the image and displaying it. A bright light shining through a spinning Nipkow disk set with lenses projected a bright spot of light which swept across the subject. A selenium photoelectric tube detected the light reflected from the subject and converted it into a proportional electrical signal. This was transmitted by AM radio waves to a receiver unit, where the video signal was applied to a neon light behind a second Nipkow disk rotating synchronized with the first. The brightness of the neon lamp was varied in proportion to the brightness of each spot on the image. As each hole in the disk passed by, one scan line of the image was reproduced. Baird's disk had 30 holes, producing an image with only 30 scan lines, just enough to recognize a human face. In 1927, Baird transmitted a signal over  of telephone line between London and Glasgow. In 1928, Baird's company (Baird Television Development Company/Cinema Television) broadcast the first transatlantic television signal, between London and New York, and the first shore-to-ship transmission. In 1929, he became involved in the first experimental mechanical television service in Germany. In November of the same year, Baird and Bernard Natan of Pathé established France's first television company, Télévision-Baird-Natan. In 1931, he made the first outdoor remote broadcast, of the Epsom Derby. In 1932, he demonstrated ultra-short wave television. Baird's mechanical system reached a peak of 240-lines of resolution on BBC television broadcasts in 1936 though the mechanical system did not scan the televised scene directly. Instead a 17.5mm film was shot, rapidly developed and then scanned while the film was still wet.

text: By the 1920s when amplification made television practical, Scottish inventor

text: John Logie Baird

text: employed the

text: Nipkow disk

text: in his prototype video systems. On March 25, 1925, Baird gave the first public demonstration of televised

text: silhouette

text: images in motion, at

text: Selfridge's

text: Department Store in London.  Since human faces had inadequate contrast to show up on his primitive system, he televised a ventriloquist's dummy named "Stooky Bill" talking and moving, whose painted face had higher contrast. By January 26, 1926, he demonstrated the transmission of image of a face in motion by radio. This is widely regarded as first television demonstration. Baird's system used the

text: Nipkow disk

text: for both scanning the image and displaying it. A bright light shining through a spinning Nipkow disk set with lenses projected a bright spot of light which swept across the subject. A selenium

text: photoelectric tube

text: scan line

text: Glasgow

text: Bernard Natan

text: of

text: Pathé

text: Baird

text: Epsom Derby

text: . In 1932, he demonstrated

text: ultra-short wave

text: BBC

text: 17.5mm film

text: The component waves follow different paths, experience different attenuations, have different phase velocities, and, in general, are elliptically polarized in opposite senses.The critical frequency of the extraordinary wave is always greater than the critical frequency of the ordinary wave (i.e. the wave in absence of the magnetic field) by the amount approximately equal to .5 times of gyro frequency .The amplitude of  extraordinary wave is dependent on the earth magnetic field at that particular point . Beside splitting, the polarization of the incident radio wave is also effected by this phenomena because the electron that were earlier in simple harmonic motion only are now in spiral motion too due to the magnetic field.

text: The component waves follow different paths, experience different attenuations, have different

text: phase velocities

text: , and, in general, are elliptically polarized in opposite senses.The

text: critical frequency

text: of the extraordinary wave is always greater than the

text: critical frequency

text: of the ordinary wave (i.e. the wave in absence of the magnetic field) by the amount approximately equal to .5 times of gyro frequency .The amplitude of  extraordinary wave is dependent on the earth magnetic field at that particular point . Beside splitting, the polarization of the incident radio wave is also effected by this phenomena because the electron that were earlier in simple harmonic motion only are now in spiral motion too due to the magnetic field.

text: Modern Radio interferometers consist of widely separated radio telescopes observing the same object that are connected together using coaxial cable, waveguide, optical fiber, or other type of transmission line. This not only increases the total signal collected, it can also be used in a process called Aperture synthesis to vastly increase resolution. This technique works by superposing ("interfering") the signal waves from the different telescopes on the principle that waves that coincide with the same phase will add to each other while two waves that have opposite phases will cancel each other out. This creates a combined telescope that is the size of the antennas furthest apart in the array. In order to produce a high quality image, a large number of different separations between different telescopes are required (the projected separation between any two telescopes as seen from the radio source is called a "baseline") - as many different baselines as possible are required in order to get a good quality image. For example, the Very Large Array has 27 telescopes giving 351 independent baselines at once.

text: Modern

text: Radio interferometers

text: consist of widely separated radio telescopes observing the same object that are connected together using

text: coaxial cable

text: waveguide

text: optical fiber

text: , or other type of

text: transmission line

text: . This not only increases the total signal collected, it can also be used in a process called

text: Aperture synthesis

text: to vastly increase resolution. This technique works by superposing ("

text: interfering

text: ") the signal

text: wave

text: s from the different telescopes on the principle that

text: wave

text: s that coincide with the same

text: phase

text: will add to each other while two waves that have opposite phases will cancel each other out. This creates a combined telescope that is the size of the antennas furthest apart in the array. In order to produce a high quality image, a large number of different separations between different telescopes are required (the projected separation between any two telescopes as seen from the radio source is called a "baseline") - as many different baselines as possible are required in order to get a good quality image. For example, the

text: Very Large Array

text: has 27 telescopes giving 351 independent baselines at once.

text: The rise of FM changed the listening habits of younger Americans.  Many stations such as WNEW-FM in New York City began to play whole sides of record albums, as opposed to the "Top 40" model of two decades earlier. In the 1980s, the Federal Communications Commission, under Reagan Administration and Congressional pressure, changed the rules limiting the number of radio and television stations a business entity could own in one metropolitan area.  This deregulation led to several groups, such as Infinity Broadcasting and Clear Channel to buy many stations in major cities.  The cost of these stations' purchases led to a conservative approach to broadcasting, including limited playlists and avoiding controversial subjects to not offend listeners, and increased commercials to increase revenue. AM radio declined throughout the 1970s and 1980s due to various reasons including: Lower cost of FM receivers, narrow AM audio bandwidth, and poor sound in the AM section of automobile receivers (to combat the crowding of stations in the AM band and a "loudness war" conducted by AM broadcasters), and increased radio noise in homes caused by fluorescent lighting and introduction of electronic devices in homes.  AM radio's decline flattened out in the mid-1990s due to the introduction of niche formats and over commercialization of many FM stations.

text: The rise of

text: FM

text: changed the listening habits of younger Americans.  Many stations such as WNEW-FM in New York City began to play whole sides of record albums, as opposed to the "Top 40" model of two decades earlier. In the 1980s, the

text: Federal Communications Commission

text: , under Reagan Administration and Congressional pressure, changed the rules limiting the number of radio and television stations a business entity could own in one metropolitan area.  This

text: deregulation

text: led to several groups, such as

text: Infinity Broadcasting

text: and

text: Clear Channel

text: to buy many stations in major cities.  The cost of these stations' purchases led to a conservative approach to broadcasting, including limited playlists and avoiding controversial subjects to not offend listeners, and increased commercials to increase revenue. AM radio declined throughout the 1970s and 1980s due to various reasons including: Lower cost of FM receivers, narrow AM audio bandwidth, and poor sound in the AM section of automobile receivers (to combat the crowding of stations in the AM band and a "

text: loudness war

text: " conducted by AM broadcasters), and increased radio noise in homes caused by fluorescent lighting and introduction of electronic devices in homes.  AM radio's decline flattened out in the mid-1990s due to the introduction of niche formats and over commercialization of many FM stations.

text: WNYC-FM (93.9 MHz) is a non-profit, noncommercial, public radio station located in New York City. It is owned by New York Public Radio which also owns WNYC (AM), WQXR-FM, New Jersey Public Radio, and the Jerome L. Greene Performance Space. Combined, New York Public Radio owns WNYC, WNYC-FM, WQXR-FM, WQXW, WNJT-FM, WNJP, WNJY, and WNJO.New York Public Radio is a not-for-profit corporation, incroporated in 1979, and is a publicly supported organization.

text: WNYC-FM (93.9 MHz) is a

text: non-profit

text: noncommercial

text: public

text: radio station

text: located in

text: New York City

text: . It is owned by

text: New York Public Radio

text: which also owns

text: WNYC (AM)

text: WQXR-FM

text: New Jersey Public Radio

text: , and the Jerome L. Greene Performance Space. Combined, New York Public Radio owns WNYC, WNYC-FM,

text: WQXR-FM

text: WQXW

text: WNJT-FM

text: WNJP

text: WNJY

text: , and

text: WNJO

text: .New York Public Radio is a not-for-profit corporation, incroporated in 1979, and is a publicly supported organization.

text: Light from many different sources contains various colors, each with its own brightness or intensity.  A rainbow, or prism, sends these component colors in different directions, making them individually visible at different angles.  A graph of the intensity plotted against the frequency (showing the brightness of each color) is the frequency spectrum of the light.  When all the visible frequencies are present equally, the perceived color of the light is white, and the spectrum is a flat line.  Therefore, flat-line spectrums in general are often referred to as white, whether they represent light or another type of wave phenomenon (sound, for example, or vibration in a structure).

text: Light from many different sources contains various colors, each with its own brightness or intensity.  A rainbow, or

text: prism

text: , sends these component colors in different directions, making them individually visible at different angles.  A graph of the intensity plotted against the frequency (showing the brightness of each color) is the frequency spectrum of the light.  When all the visible frequencies are present equally, the perceived color of the light is white, and the spectrum is a flat line.  Therefore, flat-line spectrums in general are often referred to as white, whether they represent light or another type of wave phenomenon (sound, for example, or vibration in a structure).

text: Programming is broadcast by television stations, sometimes called "channels", as stations are licensed by their governments to broadcast only over assigned channels in the television band. At first, terrestrial broadcasting was the only way television could be widely distributed, and because bandwidth was limited, i.e., there were only a small number of channels available, government regulation was the norm. In the U.S., the Federal Communications Commission (FCC) allowed stations to broadcast advertisements beginning in July 1941, but required public service programming commitments as a requirement for a license. By contrast, the United Kingdom chose a different route, imposing a television license fee on owners of television reception equipment to fund the British Broadcasting Corporation (BBC), which had public service as part of its Royal Charter.

text: Programming is

text: broadcast

text: by

text: television station

text: s, sometimes called "channels", as stations are

text: licensed

text: by their governments to broadcast only over assigned

text: channels

text: in the television

text: band

text: . At first,

text: terrestrial broadcasting

text: was the only way television could be widely distributed, and because

text: bandwidth

text: was limited, i.e., there were only a small number of

text: channels

text: available, government regulation was the norm. In the U.S., the

text: Federal Communications Commission

text: (FCC) allowed stations to broadcast advertisements beginning in July 1941, but required public service programming commitments as a requirement for a license. By contrast, the United Kingdom chose a different route, imposing a

text: television license

text: fee on owners of television reception equipment to fund the

text: British Broadcasting Corporation

text: (BBC), which had public service as part of its

text: Royal Charter

text: It was not until the advent of satellite communications in the 1980s that live syndication became popular (though it could be transmitted through network lines, it was not particularly common because of cost, network congestion and quality issues). Since then, most syndicated radio programs are distributed using satellite subcarrier audio technology. Shortly after satellite networks such as RKO, Transtar and SMN began, the Fairness Doctrine was repealed, which is credited with helping Rush Limbaugh become the first national talk radio superstar. At the same time, the FCC began issuing more FM radio licenses to suburban and rural areas in the late 1980s, which allowed more room for music stations on the FM dial; radio formats such as country music that were traditionally AM fixtures even after most pop and rock music moved to FM were now moving to FM as well, leaving much more room for talk formats on the AM dial. As the 1990s went on, Dr. Laura and Howard Stern began their national shows, rising to become national icons. The Telecommunications Act of 1996, which led to significant concentration of media ownership, facilitated the rapid deployment of both existing and new syndicated programs in the late 1990s, putting syndication on par with, and eventually surpassing, the network radio format.

text: It was not until the advent of

text: satellite communications

text: in the 1980s that live syndication became popular (though it could be transmitted through network lines, it was not particularly common because of cost, network congestion and quality issues). Since then, most syndicated radio programs are distributed using

text: satellite subcarrier audio

text: technology. Shortly after satellite networks such as

text: RKO

text: Transtar

text: and

text: SMN

text: began, the

text: Fairness Doctrine

text: was repealed, which is credited with helping

text: Rush Limbaugh

text: become the first national talk radio superstar. At the same time, the FCC began issuing more

text: FM radio

text: licenses to suburban and rural areas in the late 1980s, which allowed more room for music stations on the FM dial;

text: radio formats

text: such as

text: country music

text: that were traditionally AM fixtures even after most pop and rock music moved to FM were now moving to FM as well, leaving much more room for talk formats on the AM dial. As the 1990s went on,

text: Dr. Laura

text: and

text: Howard Stern

text: began their national shows, rising to become national icons. The

text: Telecommunications Act of 1996

text: , which led to significant

text: concentration of media ownership

text: , facilitated the rapid deployment of both existing and new syndicated programs in the late 1990s, putting syndication on par with, and eventually surpassing, the

text: network radio

text: format.

text: The largest television network in the United States, however, is the Public Broadcasting Service (PBS), a non-profit, publicly owned, non-commercial educational service. In comparison to the commercial television networks, there is no central unified arm of broadcast programming, meaning that each PBS member station has a significant amount of freedom to schedule television shows as they consent to. Some public television outlets, such as PBS, carry separate digital subchannel networks through their member stations (for example, Georgia Public Broadcasting; in fact, some programs airing on PBS were branded on other channels as coming from GPB Kids and PBS World).

text: The largest television network in the United States, however, is the Public Broadcasting Service (

text: PBS

text: ), a

text: non-profit

text: , publicly owned,

text: non-commercial educational

text: service. In comparison to the

text: commercial television

text: networks, there is no central unified arm of broadcast programming, meaning that each PBS

text: member station

text: has a significant amount of freedom to schedule television shows as they consent to. Some public television outlets, such as PBS, carry separate

text: digital subchannel

text: networks through their member stations (for example,

text: Georgia Public Broadcasting

text: ; in fact, some programs airing on PBS were branded on other channels as coming from GPB Kids and

text: PBS World

text: Pirate radio generally describes the unlicensed broadcast of FM radio, AM radio, or short wave signals over a wide range. In some cases radio stations are deemed legal where the signal is transmitted, but illegal where the signals are received—especially when the signals cross a national boundary. In other cases, a broadcast may be considered "pirate" due to the nature of its content, its transmission format (especially a failure to transmit a station identification according to regulations), or the transmit power (wattage) of the station, even if the transmission is not technically illegal (such as a web cast or an amateur radio transmission).  Pirate radio stations are sometimes called bootleg stations (a term especially associated with two-way radio), clandestine stations (associated with heavily politically motivated operations)  or free radio stations.

text: Pirate radio generally describes the unlicensed broadcast of

text: FM radio

text: AM radio

text: , or

text: short wave

text: signals over a wide range. In some cases radio stations are deemed legal where the signal is transmitted, but illegal where the signals are received—especially when the signals cross a national boundary. In other cases, a broadcast may be considered "pirate" due to the nature of its content, its transmission format (especially a failure to transmit a

text: station identification

text: according to regulations), or the transmit power (wattage) of the station, even if the transmission is not technically illegal (such as a

text: web cast

text: or an

text: amateur radio

text: transmission).  Pirate radio stations are sometimes called bootleg stations (a term especially associated with

text: two-way radio

text: ), clandestine stations (associated with heavily politically motivated operations)  or free radio stations.

text: FM radio stations in the area are WRRV-96.9 (alternative rock), WPDH-101.5 (album-oriented rock), WCZX-Mix 97.7 (adult contemporary), WKXP-94.3 The Wolf (Country), WRWD-FM-107.3 (country), WSPK-104.7 (top 40), WHUD-100.7 (adult contemporary), WDST-100.1 (independent rock), WPKF-96.1 (rhythmic top 40) and WVKR-91.3 (Vassar College Radio). AM radio stations in the area are WEOK-AM 1390 (Oldies), WGNY-1220 (sports), WHVW-950 (50's and older blues and country), WKIP-1450 (talk radio).

text: FM radio stations in the area are

text: WRRV

text: -96.9 (alternative rock),

text: WPDH

text: -101.5 (album-oriented rock),

text: WCZX

text: -Mix 97.7 (adult contemporary),

text: WKXP

text: -94.3 The Wolf (Country),

text: WRWD-FM

text: -107.3 (country),

text: WSPK

text: -104.7 (top 40),

text: WHUD

text: -100.7 (adult contemporary),

text: WDST

text: -100.1 (independent rock),

text: WPKF

text: -96.1 (rhythmic top 40) and

text: WVKR

text: -91.3 (Vassar College Radio). AM radio stations in the area are

text: WEOK

text: -AM 1390 (Oldies),

text: WGNY

text: -1220 (sports),

text: WHVW

text: -950 (50's and older blues and country),

text: WKIP

text: -1450 (talk radio).

text: Radio Enciclopedia is a soft music radio network of transmitters broadcast throughout Cuba on medium wave (AM) and VHF (FM). The main frequencies in Havana are 94.1 (FM) and 1260 (AM). It can also be heard for several hundred miles beyond Cuba's borders on 530 (AM) and worldwide via the Internet. It only broadcasts instrumental music. It is one of four main radio stations in Cuba.

text: In amplitude modulation, the amplitude or "strength" of the carrier oscillations is what is varied.  For example, in AM radio communication, a continuous wave radio-frequency signal (a sinusoidal carrier wave) has its amplitude modulated by an audio waveform before transmission.     The audio waveform modifies the amplitude of the carrier wave and determines the envelope of the waveform. In the frequency domain, amplitude modulation produces a signal with power concentrated at the carrier frequency and two adjacent sidebands. Each sideband is equal in bandwidth to that of the modulating signal, and is a mirror image of the other. Standard AM is thus sometimes called "double-sideband amplitude modulation" (DSB-AM) to distinguish it from more sophisticated modulation methods also based on AM.

text: In amplitude modulation, the

text: amplitude

text: or "strength" of the carrier oscillations is what is varied.  For example, in AM radio communication, a

text: continuous wave

text: radio-frequency signal (a

text: sinusoid

text: al

text: carrier wave

text: ) has its

text: amplitude

text: modulated

text: by an audio waveform before transmission.     The audio waveform modifies the amplitude of the carrier wave and determines the

text: envelope

text: of the waveform. In the

text: frequency domain

text: , amplitude modulation produces a signal with power concentrated at the

text: carrier frequency

text: and two adjacent

text: sideband

text: s. Each sideband is equal in

text: bandwidth

text: to that of the modulating signal, and is a mirror image of the other. Standard AM is thus sometimes called "double-sideband amplitude modulation" (DSB-AM) to distinguish it from more sophisticated modulation methods also based on AM.

text: Radar is an object-detection system that uses radio waves to determine the range, angle, or velocity of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the object(s). Radio waves (pulsed or continuous) from the transmitter reflect off the object and return to the receiver, giving information about the object's location and speed.

text: Radar is an object-detection system that uses

text: radio wave

text: s to determine the range, angle, or velocity of objects. It can be used to detect

text: aircraft

text: , ships,

text: spacecraft

text: guided missiles

text: motor vehicle

text: s,

text: weather formations

text: , and terrain. A radar system consists of a

text: transmitter

text: producing

text: electromagnetic wave

text: s in the radio or

text: microwave

text: s domain, a transmitting

text: antenna

text: , a receiving antenna (often the same antenna is used for transmitting and receiving) and a

text: receiver

text: and

text: processor

text: to determine properties of the object(s). Radio waves (pulsed or continuous) from the transmitter reflect off the object and return to the receiver, giving information about the object's location and speed.

text: The city has a variety of AM and FM radio stations. Two AM and two FM stations in Hyderabad are operated by All India Radio (AIR), officially known as Akashvani. The first FM radio station to broadcast in the city was AIR's Vividh Bharati in the early 1990s. In 2006, commercial FM radio stations were launched in Hyderabad. These stations are broadcast 24 hours a day, seven days a week with programming in Telugu and Hindi. The FM radio stations in the city are:

text: The city has a variety of AM and FM radio stations. Two

text: AM

text: and two

text: FM

text: stations in Hyderabad are operated by

text: All India Radio

text: (AIR), officially known as Akashvani. The first FM radio station to broadcast in the city was AIR's

text: Vividh Bharati

text: in the early 1990s. In 2006,

text: commercial

text: FM radio stations were launched in Hyderabad. These stations are broadcast 24 hours a day, seven days a week with programming in

text: Telugu

text: and

text: Hindi

text: . The FM radio stations in the city are:

text: Classically, electromagnetic radiation consists of electromagnetic waves, which are synchronized oscillations of electric and magnetic fields that propagate at the speed of light through a vacuum.  The oscillations of the two fields are perpendicular to each other and perpendicular to the direction of energy and wave propagation, forming a transverse wave. Electromagnetic waves can be characterized by either the frequency or wavelength of their oscillations, which determines their position in the electromagnetic spectrum, which includes, in order of increasing frequency and decreasing wavelength: radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays.

text: Classically

text: , electromagnetic radiation consists of electromagnetic waves, which are synchronized

text: oscillation

text: s of

text: electric

text: and

text: magnetic

text: fields that propagate at the

text: speed of light

text: through a

text: vacuum

text: .  The oscillations of the two fields are perpendicular to each other and perpendicular to the direction of energy and wave propagation, forming a

text: transverse wave

text: . Electromagnetic waves can be characterized by either the

text: frequency

text: or

text: wavelength

text: of their oscillations, which determines their position in the

text: electromagnetic spectrum

text: , which includes, in order of increasing frequency and decreasing wavelength:

text: radio wave

text: s,

text: microwave

text: s,

text: infrared

text: radiation,

text: visible light

text: ultraviolet radiation

text: X-ray

text: s and

text: gamma ray

text: s.

text: The Conservative government decided that to increase competition on AM and disallowed the simulcasting of services on both AM and FM, affecting both BBC and ILR. Radio 1's medium wave frequencies were reallocated to Independent National Radio. Radio 1's last broadcast on MW was on 1 July 1994, with Stephen Duffy's "Kiss Me" being the last record played on MW just before 9:00 am. In the initial months after this closure a pre-recorded message with Mark Goodier was played to warn listeners that Radio 1 was now an "FM-only" station. During this time Radio 1 began broadcasting on spare audio subcarriers on Sky Television's analogue satellite service, initially in mono (on UK Gold) and later in stereo (on UK Living).

text: The Conservative government decided that to increase competition on AM and disallowed the simulcasting of services on both AM and FM, affecting both BBC and ILR. Radio 1's medium wave frequencies were reallocated to

text: Independent National Radio

text: . Radio 1's last broadcast on MW was on 1 July 1994, with

text: Stephen Duffy

text: 's "Kiss Me" being the last record played on MW just before 9:00 am. In the initial months after this closure a pre-recorded message with

text: Mark Goodier

text: was played to warn listeners that Radio 1 was now an "FM-only" station. During this time Radio 1 began broadcasting on spare audio subcarriers on

text: Sky Television's

text: analogue satellite service, initially in mono (on

text: UK Gold

text: ) and later in stereo (on

text: UK Living

text: Sunshine Radio was the first of the so-called Super Pirate radio stations in the Republic of Ireland and commenced broadcasting on September 9, 1980 from studios in the Sands Hotel,  Portmarnock, County Dublin. It was the longest operating of the major stations. Sunshine closed at the end of 1988 having achieved the highest ratings of any Dublin radio station to this day. Their head office was in JWT House in Baggot Street in the heart of the city's commercial district. Sunshine Radio was set up by former Radio Caroline men Chris Cary, Robbie Robinson, aka Robbie Dale, and ex-BBC broadcast engineer Jimmy White with some financial support from one of Radio Caroline's partners Phil Solomon. Shortly after making its first test transmissions the stations main aerial tower was vandalised and subsequently collapsed. Cary and Solomon backed out of the venture and sold to Dale only weeks after the station opened. Sunshine Radio started on 531 kHz (announced as 539 metres) medium wave, adding an FM service a year later. Chris Cary went on to start Radio Nova in the following year, 1981, with studios in Herbert Street, Dublin.  Nova was the first major Irish pirate to commence with FM, on 88.1 MHz (it ended up on 102.7 MHz). The station added an AM frequency at a later stage which varied between 819 kHz, 828 kHz  846 kHz and 738 kHz. After the success of Radio Nova on FM, Robbie Robinson broadcast Sunshine at high power on 101 MHz, and renamed the station Sunshine 101. Nova ran until 1986 when Chris Cary closed the station following a dispute with the National Union of Journalists. Other stations came on air like Q102 some claiming a Cary connection like NRG 103 (some thought that "NRG" was an abbreviation for "Nova Radio Group"), but the name sounded like Energy 103 and Power FM, but none were able to come near to the Nova or Sunshine success. Sunshine 101 dominated the Dublin radio market until it closed down at the end of December 1988 in compliance with the new Broadcasting & Wireless Telegraphy act, which had come into effect at midnight on December 31 that year. Many of the present day stars of Irish broadcasting are proud to acknowledge their early days as part of the teams to come out of Sunshine and Nova.

text: Sunshine Radio was the first of the so-called Super Pirate radio stations in the Republic of Ireland and commenced broadcasting on September 9, 1980 from studios in the Sands Hotel,

text: Portmarnock

text: County Dublin

text: . It was the longest operating of the major stations. Sunshine closed at the end of 1988 having achieved the highest ratings of any Dublin radio station to this day. Their head office was in JWT House in Baggot Street in the heart of the city's commercial district. Sunshine Radio was set up by former

text: Radio Caroline

text: men

text: Chris Cary

text: , Robbie Robinson, aka

text: Robbie Dale

text: , and ex-BBC broadcast engineer

text: Jimmy White

text: with some financial support from one of Radio Caroline's partners

text: Phil Solomon

text: . Shortly after making its first test transmissions the stations main aerial tower was vandalised and subsequently collapsed. Cary and Solomon backed out of the venture and sold to Dale only weeks after the station opened. Sunshine Radio started on 531 kHz (announced as 539 metres) medium wave, adding an FM service a year later. Chris Cary went on to start

text: Radio Nova

text: in the following year, 1981, with studios in Herbert Street, Dublin.  Nova was the first major Irish pirate to commence with FM, on 88.1 MHz (it ended up on 102.7 MHz). The station added an AM frequency at a later stage which varied between 819 kHz, 828 kHz  846 kHz and 738 kHz. After the success of Radio Nova on FM, Robbie Robinson broadcast Sunshine at high power on 101 MHz, and renamed the station Sunshine 101. Nova ran until 1986 when Chris Cary closed the station following a dispute with the

text: National Union of Journalists

text: . Other stations came on air like Q102 some claiming a Cary connection like NRG 103 (some thought that "NRG" was an abbreviation for "Nova Radio Group"), but the name sounded like Energy 103 and Power FM, but none were able to come near to the Nova or Sunshine success. Sunshine 101 dominated the Dublin radio market until it closed down at the end of December 1988 in compliance with the new Broadcasting & Wireless Telegraphy act, which had come into effect at midnight on December 31 that year. Many of the present day stars of Irish broadcasting are proud to acknowledge their early days as part of the teams to come out of Sunshine and Nova.

text: Extremely high frequency (EHF) is the International Telecommunications Union (ITU) designation for the band of radio frequencies in the electromagnetic spectrum from 30 to 300 gigahertz. It lies between the super high frequency band, and the far infrared band which is also referred to as the terahertz gap. Radio waves in this band have wavelengths from ten to one millimetre, giving it the name millimetre band or millimetre wave, sometimes abbreviated MMW or mmW. Millimetre-length electromagnetic waves were first investigated in the 1890s by Indian scientist Jagadish Chandra Bose.

text: Extremely high frequency (EHF) is the

text: International Telecommunications Union

text: (ITU) designation for the band of

text: radio frequencies

text: in the

text: electromagnetic spectrum

text: from 30 to 300

text: gigahertz

text: . It lies between the

text: super high frequency

text: band, and the

text: far infrared

text: band which is also referred to as the

text: terahertz gap

text: Radio wave

text: s in this band have

text: wavelength

text: s from ten to one millimetre, giving it the name millimetre band or millimetre wave, sometimes abbreviated MMW or mmW. Millimetre-length electromagnetic waves were first investigated in the 1890s by Indian scientist

text: Jagadish Chandra Bose

text: From the start of broadcasting in 1975, TFM (then known as Radio Tees) was owned by Sound Broadcasting (Teesside) Ltd and originally broadcast on 257 Medium Wave only, with a later launch on 95 VHF. After a government radio frequency re shuffle in the mid-1980s, the FM frequency was swapped with BBC Radio Cleveland and Radio Tees shifted to 96.6 FM in 1986. In 1988 Radio Tees was relaunched as TFM 96.6 after being taken over by Newcastle upon Tyne based Metro Radio Group. Shortly after this, a new Medium Wave station called Great North Radio (GNR) was launched after broadcasting rules meant TFM could not broadcast on both FM and Medium Wave.

text: From the start of broadcasting in 1975, TFM (then known as

text: Radio Tees

text: ) was owned by Sound Broadcasting (Teesside) Ltd and originally broadcast on 257 Medium Wave only, with a later launch on 95 VHF. After a government radio frequency re shuffle in the mid-1980s, the FM frequency was swapped with

text: BBC Radio Cleveland

text: and Radio Tees shifted to 96.6 FM in 1986. In 1988 Radio Tees was relaunched as TFM 96.6 after being taken over by

text: Newcastle upon Tyne

text: based

text: Metro Radio Group

text: . Shortly after this, a new Medium Wave station called

text: Great North Radio

text: (GNR) was launched after broadcasting rules meant TFM could not broadcast on both FM and Medium Wave.

text: In the 1940s, the paper extended its breadth and reach. The crossword began appearing regularly in 1942, and the fashion section in 1946. The New York Times began an international edition in 1946. The international edition stopped publishing in 1967, when The New York Times joined the owners of the New York Herald Tribune and The Washington Post to publish the International Herald Tribune in Paris. The paper bought AM radio station WQXR (1560kHz) in 1944. Its "sister" FM station, WQXQ, would become WQXR-FM (96.3MHz). Branded as "The Radio Stations of The New York Times", its classical music radio format was simulcast on both the AM & FM frequencies until December 1992, when the big-band and pop standards music format of station WNEW (1130kHz – now WBBR/"Bloomberg Radio") was transferred to and adopted by WQXR; in recognition of the format change, WQXR changed its call letters to WQEW (a "hybrid" combination of "WQXR" and "WNEW"). By 1999, The New York Times was leasing WQEW to ABC Radio for its "Radio Disney" format. In 2007, WQEW was finally purchased by Disney; in late 2014, it was sold to Family Radio (a religious radio network) and became WFME. On July 14, 2009, it was announced that WQXR-FM would be sold to the WNYC radio group who, on October 8, 2009, moved the station from 96.3 to 105.9MHz (swapping frequencies with Spanish-language station WXNY-FM, which wanted the more powerful transmitter to increase its coverage) and began operating it as a non-commercial, public radio station. After the purchase, WQXR-FM retained the classical music format, whereas WNYC-FM (93.9MHz) abandoned it, switching to a talk radio format.

text: In the 1940s, the paper extended its breadth and reach. The

text: crossword

text: began appearing regularly in 1942, and the fashion section in 1946. The New York Times began an international edition in 1946. The international edition stopped publishing in 1967, when The New York Times joined the owners of the

text: New York Herald Tribune

text: and

text: The Washington Post

text: to publish the

text: International Herald Tribune

text: in Paris. The paper bought AM radio station

text: WQXR

text: (1560kHz) in 1944. Its "sister" FM station, WQXQ, would become WQXR-FM (96.3MHz). Branded as "The Radio Stations of The New York Times", its

text: classical music

text: radio format

text: was simulcast on both the AM & FM frequencies until December 1992, when the big-band and pop standards music format of station WNEW (1130kHz – now

text: WBBR

text: /"Bloomberg Radio") was transferred to and adopted by WQXR; in recognition of the format change, WQXR changed its call letters to

text: WQEW

text: (a "hybrid" combination of "WQXR" and "WNEW"). By 1999, The New York Times was leasing WQEW to

text: ABC Radio

text: for its "

text: Radio Disney

text: " format. In 2007, WQEW was finally purchased by

text: Disney

text: ; in late 2014, it was sold to Family Radio (a religious radio network) and became

text: WFME

text: . On July 14, 2009, it was announced that WQXR-FM would be sold to the

text: WNYC

text: radio group who, on October 8, 2009, moved the station from 96.3 to 105.9MHz (swapping frequencies with Spanish-language station

text: WXNY-FM

text: , which wanted the more powerful transmitter to increase its coverage) and began operating it as a non-commercial, public radio station. After the purchase, WQXR-FM retained the classical music format, whereas WNYC-FM (93.9MHz) abandoned it, switching to a

text: talk radio

text: format.

text: Viking was the first commercial radio station in the UK to introduce split programming so that it could broadcast rugby league commentary on Sunday afternoons on its AM frequency, leaving FM to take The Network Chart Show. On 31 October 1988, Viking Radio split frequencies on a permanent basis and was transformed into Viking FM on 96.9 FM and Viking Gold on 1161 (said "Double-One Six-One") medium wave. The AM station later became Classic Gold, Classic Gold Radio, Great Yorkshire Gold, Great Yorkshire Radio, Magic 1161 (pronounced "Eleven-Sixty-One") and from 2015, Viking 2.

text: Viking was the first commercial radio station in the UK to introduce split programming so that it could broadcast rugby league commentary on Sunday afternoons on its AM frequency, leaving FM to take

text: The Network Chart Show

text: . On 31 October 1988, Viking Radio split frequencies on a permanent basis and was transformed into Viking FM on 96.9 FM and Viking Gold on 1161 (said "Double-One Six-One") medium wave. The AM station later became Classic Gold, Classic Gold Radio, Great Yorkshire Gold, Great Yorkshire Radio, Magic 1161 (pronounced "Eleven-Sixty-One") and from 2015,

text: Viking 2

text: Several different types of propagation are used in practical radio transmission systems.   Line-of-sight propagation means radio waves which travel in a straight line from the transmitting antenna to the receiving antenna.  It does not necessarily require a cleared sight path; at lower frequencies radio waves can pass through building walls and foliage. Line of sight transmission is used in short to medium range radio transmission such as garage door openers, cell phones, cordless phones, walkie-talkies, wireless networks,  FM radio and television broadcasting and radar, and satellite communication, such as satellite television.  Line-of-sight transmission on the surface of the Earth is limited to the distance to the visual horizon, about 40 miles.   It is the only propagation method possible at microwave frequencies and above.  At microwave frequencies moisture in the atmosphere (rain fade) can degrade transmission.

text: Several different types of propagation are used in practical radio transmission systems.

text: Line-of-sight propagation

text: means radio waves which travel in a straight line from the transmitting antenna to the receiving antenna.  It does not necessarily require a cleared sight path; at lower frequencies radio waves can pass through building walls and foliage. Line of sight transmission is used in short to medium range radio transmission such as

text: garage door opener

text: s,

text: cell phone

text: s,

text: cordless phone

text: s,

text: walkie-talkie

text: s,

text: wireless network

text: s,

text: FM radio

text: and

text: television broadcasting

text: and

text: radar

text: , and

text: satellite communication

text: , such as

text: satellite television

text: .  Line-of-sight transmission on the surface of the Earth is limited to the distance to the visual horizon, about 40 miles.   It is the only propagation method possible at

text: microwave

text: frequencies and above.  At microwave frequencies moisture in the atmosphere (

text: rain fade

text: ) can degrade transmission.

text: WAVE-AM was the long-time radio sister of WAVE-TV (channel 3). For many years, it aired a full-service MOR format, which later shifted to oldies. In 1988, WAVE-AM was sold to Radio One (not related to the company that would eventually buy stations in the Louisville market in the late 1990s), which forced the radio station to change call letters to WAVG. In the Fall of 1989, the station dropped local programming and switched to a satellite-fed oldies format. On September 4, 1990, WAVG switched to an adult standards format. In 1991, WAVG was sold to Sunnyside Communications. On January 8, 1997, Sunnyside announced they would sell WAVG to Pulitzer, then-owners of WLKY-TV, who announced plans to flip the station to an all-news format, with AP News Radio programming and simulcasts of WLKY's newscasts. The changeover took place at Noon on June 16; at the same time, the WAVG call letters and standards format would move to 1450 AM, while 970 adopted the WLKY-AM call letters. In August 2000, Hearst-Argyle (which bought all of Pulitzer's broadcasting outlets the year before) sold the station to current owner Salem Communications, and flipped it to a news/talk format.

text: WAVE-AM was the long-time radio sister of

text: WAVE-TV

text: (channel 3). For many years, it aired a full-service

text: MOR

text: format, which later shifted to

text: oldies

text: . In 1988, WAVE-AM was sold to Radio One (not related to the

text: company

text: that would eventually buy stations in the Louisville market in the late 1990s), which forced the radio station to change call letters to WAVG. In the Fall of 1989, the station dropped local programming and switched to a satellite-fed oldies format. On September 4, 1990, WAVG switched to an

text: adult standards

text: format. In 1991, WAVG was sold to Sunnyside Communications. On January 8, 1997, Sunnyside announced they would sell WAVG to

text: Pulitzer

text: , then-owners of

text: WLKY-TV

text: , who announced plans to flip the station to an

text: all-news

text: format, with AP News Radio programming and simulcasts of WLKY's newscasts. The changeover took place at Noon on June 16; at the same time, the WAVG call letters and standards format would move to

text: 1450 AM

text: , while 970 adopted the WLKY-AM call letters. In August 2000,

text: Hearst-Argyle

text: (which bought all of Pulitzer's broadcasting outlets the year before) sold the station to current owner

text: Salem Communications

text: , and flipped it to a

text: news/talk

text: format.

text: Radio Azadi (formerly Radio Free Afghanistan) is the Afghan branch of the U.S. government's Radio Free Europe / Radio Liberty’s (RFE/RL) external broadcast services. It broadcasts 12 hours daily as part of a 24-hour stream of programming in conjunction with Voice of America (VOA). Radio Free Afghanistan first aired in Afghanistan from 1985 to 1993 and was re-launched in January 2002. Radio Azadi produces a variety of cultural, political, and informational programs that are transmitted to listeners via shortwave radio, satellite and AM and FM signals provided by the International Broadcasting Bureau. According to Radio Azadi, their mission is "to promote and sustain democratic values and institutions in Afghanistan by disseminating news, factual information and ideas".

text: Radio Azadi (formerly Radio Free Afghanistan) is the Afghan branch of the

text: U.S. government's

text: Radio Free Europe / Radio Liberty’s (RFE/RL)

text: external broadcast services. It broadcasts 12 hours daily as part of a 24-hour stream of programming in conjunction with

text: Voice of America

text: (VOA). Radio Free Afghanistan first aired in

text: Afghanistan

text: from 1985 to 1993 and was re-launched in January 2002. Radio Azadi produces a variety of cultural, political, and informational programs that are transmitted to listeners via

text: shortwave radio

text: , satellite and

text: AM

text: and

text: FM

text: signals provided by the

text: International Broadcasting Bureau

text: . According to Radio Azadi, their mission is "to promote and sustain democratic values and institutions in Afghanistan by disseminating news, factual information and ideas".

text: Historically, radio has been the most prevalent form of mass communication in Nepal. Government-owned Radio Nepal has been the sole domestic radio provider since 1951, and by 1995 it was broadcasting in short-wave, medium-wave, and FM frequencies. Private operators can lease the FM channel, and there are plans to establish FM stations outside the capital.

text: Historically,

text: radio

text: has been the most prevalent form of mass communication in Nepal. Government-owned

text: Radio Nepal

text: has been the sole domestic radio provider since 1951, and by 1995 it was broadcasting in short-wave, medium-wave, and FM frequencies. Private operators can lease the FM channel, and there are plans to establish FM stations outside the capital.

text: The combined absorption spectra of the gases in the atmosphere leave "windows" of low opacity, allowing the transmission of only certain bands of light. The optical window runs from around 300 nm (ultraviolet-C) up into the range humans can see, the visible spectrum (commonly called light), at roughly 400–700 nm and continues to the infrared to around 1100 nm. There are also infrared and radio windows that transmit some infrared and radio waves at longer wavelengths. For example, the radio window runs from about one centimeter to about eleven-meter waves.

text: The combined

text: absorption spectra

text: of the gases in the atmosphere leave "windows" of low

text: opacity

text: , allowing the transmission of only certain bands of light. The

text: optical window

text: runs from around 300 nm (

text: ultraviolet

text: -C) up into the range humans can see, the

text: visible spectrum

text: (commonly called

text: light

text: ), at roughly 400–700 nm and continues to the

text: infrared

text: to around 1100 nm. There are also

text: infrared

text: and

text: radio window

text: s that transmit some infrared and

text: radio waves

text: at longer wavelengths. For example, the radio window runs from about one centimeter to about eleven-meter waves.

text: There was a great deal of interest in radio waves in the physics community, but the interest was in radio as a scientific phenomenon, not in its potential as a communication method.  Physicists generally looked on radio waves as an invisible form of light, a short range phenomenon which could only travel along a line of sight path, and thus its range was limited to the visual horizon like existing forms of visual signaling, making it unsuitable for long distance communication. Hertz's death in 1894 brought published reviews of his earlier discoveries including a demonstration on the transmission and detection of radio waves by the British physicist Oliver Lodge and an article about Hertz's work by Marconi's teacher, Augusto Righi. Righi's article renewed Marconi's interest in developing a wireless telegraphy system based on radio waves, a line of inquiry that he noted other inventors did not seem to be pursuing.

text: There was a great deal of interest in radio waves in the physics community, but the interest was in radio as a scientific phenomenon, not in its potential as a communication method.  Physicists generally looked on radio waves as an invisible form of light, a short range phenomenon which could only travel along a

text: line of sight

text: path, and thus its range was limited to the visual horizon like existing forms of visual signaling, making it unsuitable for long distance communication. Hertz's death in 1894 brought published reviews of his earlier discoveries including a demonstration on the transmission and detection of radio waves by the British physicist

text: Oliver Lodge

text: and an article about Hertz's work by Marconi's teacher, Augusto Righi. Righi's article renewed Marconi's interest in developing a wireless telegraphy system based on radio waves, a line of inquiry that he noted other inventors did not seem to be pursuing.

text: In 1993, Bohdan Paczyński and James E. Rhoads published an article arguing that, regardless of the type of explosion that causes GRBs, the extreme energetics of GRBs meant that matter from the host body must be ejected at relativistic speeds during the explosion. They predicted that the interaction between the ejecta and interstellar matter would create a shock front. Should this shock front occur in a magnetic field, accelerated electrons in it would emit long-lasting synchrotron radiation in the radio frequencies, a phenomenon that would later be referred to as a radio afterglow. Jonathan Katz later concluded that this lower-energy emission would not be limited to radio waves, but should range in frequency from radio waves to x-rays, including visible light.

text: In 1993,

text: Bohdan Paczyński

text: and James E. Rhoads published an article arguing that, regardless of the type of explosion that causes GRBs, the extreme energetics of GRBs meant that matter from the host body must be ejected at

text: relativistic speed

text: s during the explosion. They predicted that the interaction between the ejecta and

text: interstellar matter

text: would create a

text: shock front

text: . Should this shock front occur in a magnetic field, accelerated electrons in it would emit long-lasting

text: synchrotron radiation

text: in the

text: radio frequencies

text: , a phenomenon that would later be referred to as a radio afterglow. Jonathan Katz later concluded that this lower-energy emission would not be limited to radio waves, but should range in frequency from radio waves to

text: x-ray

text: s, including

text: visible light

text: The Burghead transmitting station is a broadcasting facility near Burghead () in Scotland for long wave and medium wave radio transmission that started service on 12 October 1936. The site is owned by Arqiva and houses a long wave radio transmitter on 198 kHz broadcasting BBC Radio 4 and two medium wave radio transmitters, broadcasting BBC Radio 5 Live on 693 kHz and BBC Radio Scotland on 810 kHz. The long wave transmitter is part of a network transmitting on the same frequency, the other transmitters being at the Droitwich and Westerglen.

text: The Burghead transmitting station is a

text: broadcasting

text: facility near

text: Burghead

text: () in

text: Scotland

text: for

text: long wave

text: and

text: medium wave

text: radio transmission that started service on 12 October 1936. The site is owned by

text: Arqiva

text: and houses a long wave radio transmitter on 198 kHz broadcasting

text: BBC Radio 4

text: and two medium wave radio transmitters, broadcasting

text: BBC Radio 5 Live

text: on 693 kHz and

text: BBC Radio Scotland

text: on 810 kHz. The long wave transmitter is part of a network transmitting on the same frequency, the other transmitters being at the

text: Droitwich

text: and

text: Westerglen

text: The station was launched after East Anglian Radio decided to make better use of the group's medium wave frequencies. On 24 September 1995, the AM frequencies of Broadland and SGR fm  became Amber Radio, playing mainly music from the 1960s and 1970s, allowing the FM stations to focus more on current and recent chart hits. All the stations were programmed by EAR group programme director Mike Stewart, with Dave Brown in Norwich and Mark Pryke as local heads of presentation.

text: The station was launched after

text: East Anglian Radio

text: decided to make better use of the group's

text: medium wave

text: frequencies. On 24 September 1995, the AM frequencies of Broadland and SGR fm  became Amber Radio, playing mainly music from the 1960s and 1970s, allowing the FM stations to focus more on current and recent chart hits. All the stations were programmed by EAR group programme director Mike Stewart, with Dave Brown in Norwich and Mark Pryke as local heads of presentation.

text: Amateur radio is a hobby and, by law, completely non-commercial. Individual amateur "ham" radio operators pursue the avocation for personal pleasure through building their own radio stations and communicating with their fellows globally, and for self-improvement via study and practice of electronics, computers, and radio and TV wave behavior. Radio amateurs are, thus, "amateurs" in the true sense of the word: pursuit of an activity only for the love of it. Radio amateurs can not broadcast or transmit music and other general public entertainment programming. The amateur radio use of the air waves is for personal satisfaction and for forwarding the "state of the art" of electronics and communication techniques. Amateur radio operations can be detected in designated bands throughout the radio spectrum, using a variety of modulation methods including Morse code, voice and digital modes, and image modes such as television and facsimile.

text: Amateur radio is a hobby and, by law, completely non-commercial. Individual amateur "ham" radio operators pursue the

text: avocation

text: for personal pleasure through building their own radio stations and communicating with their fellows globally, and for self-improvement via study and practice of electronics, computers, and radio and TV wave behavior. Radio amateurs are, thus, "amateurs" in the true sense of the word: pursuit of an activity only for the love of it. Radio amateurs can not broadcast or transmit music and other general public entertainment programming. The amateur radio use of the air waves is for personal satisfaction and for forwarding the "state of the art" of electronics and communication techniques. Amateur radio operations can be detected in designated bands throughout the

text: radio spectrum

text: , using a variety of

text: modulation

text: methods including

text: Morse code

text: , voice and

text: digital

text: modes, and image modes such as

text: television

text: and

text: facsimile

text: The region receives five ABC radio services –  ABC Illawarra 97.3FM, Triple J 98.9, and Radio National 1431 AM, ABC Classic FM 95.7 and Newsradio 90.9FM. There are two commercial radio stations i98FM 98.1 and WAVE FM 96.5 - formerly 2WL,  and two community radio stations Vox FM 106.9 and Christian broadcaster 94.1 FM. Nowra's Power FM 94.9 also reaches the city, as do most Sydney commercial radio stations.

text: The region receives five ABC radio services –  ABC Illawarra 97.3FM,

text: Triple J

text: 98.9, and

text: Radio National

text: 1431 AM,

text: ABC Classic FM

text: 95.7 and Newsradio 90.9FM. There are two commercial radio stations

text: 98.1 and WAVE FM 96.5 - formerly 2WL,  and two

text: community radio

text: stations

text: Vox FM

text: 106.9 and Christian broadcaster 94.1 FM. Nowra's Power FM 94.9 also reaches the city, as do most Sydney commercial radio stations.

text: Television signals were initially distributed only as terrestrial television using high-powered radio-frequency transmitters to broadcast the signal to individual television receivers. Alternatively television signals are distributed by coaxial cable or optical fiber, satellite systems and, since the 2000s via the Internet. Until the early 2000s, these were transmitted as analog signals but countries started switching to digital, this transition is expected to be completed worldwide by late 2010s. A standard television set is composed of multiple internal electronic circuits, including a tuner for receiving and decoding broadcast signals. A visual display device which lacks a tuner is correctly called a video monitor rather than a television.

text: Television signals were initially distributed only as

text: terrestrial television

text: using high-powered

text: radio-frequency

text: transmitters to

text: broadcast

text: the signal to individual television receivers. Alternatively television signals are distributed by

text: coaxial cable or optical fiber

text: satellite

text: systems and, since the 2000s via the

text: Internet

text: . Until the early 2000s, these were transmitted as

text: analog

text: signals but countries started switching to digital, this

text: transition

text: is expected to be completed worldwide by late 2010s. A standard television set is composed of multiple internal

text: electronic circuit

text: s, including a tuner for

text: receiving

text: and decoding broadcast signals. A visual

text: display device

text: which lacks a

text: tuner

text: is correctly called a

text: video monitor

text: rather than a television.

text: Whispering-gallery waves have also been demonstrated for other electromagnetic waves such as radio waves, microwaves, terahertz radiation, infrared radiation, ultraviolet waves and x-rays.

text: Whispering-gallery waves have also been demonstrated for other

text: electromagnetic wave

text: s such as

text: radio wave

text: s,

text: microwave

text: s,

text: terahertz radiation

text: infrared radiation

text: ultraviolet waves

text: and

text: x-ray

text: s.

text: Cable television is a system of broadcasting television programming to paying subscribers via radio frequency (RF) signals transmitted through coaxial cables or light pulses through fiber-optic cables. This contrasts with traditional terrestrial television, in which the television signal is transmitted over the air by radio waves and received by a television antenna attached to the television. FM radio programming, high-speed Internet, telephone service, and similar non-television services may also be provided through these cables.

text: In 2005 Cubans had at least 3.9 million radio receivers and 3 million television sets, and the country had 169 AM, 55 FM, and 58 TV broadcasting stations. The Cuban Institute of Radio and Television serves as the government’s administrative outlet for broadcasting. Of the six national AM/FM radio networks, the top three are Radio Progreso, Radio Reloj, and Radio Rebelde, in that order. Two other national radio networks that also provide news and entertainment are Radio Musical Nacional (CMBF) and Radio Enciclopedia. Another station, Radio Taíno, promotes tourism. The Cuban government also operates Radio Havana, the official Cuban international short-wave radio service. The Cuban television system is made up of two networks: Cubavisión and Tele Rebelde. Cuba’s restriction of foreign broadcast media is one reason the U.S. government has sponsored radio and television broadcasting into Cuba through Radio y Televisión Martí, much of which is jammed.

text: In 2005 Cubans had at least 3.9 million

text: radio

text: receivers and 3 million

text: television set

text: s, and the country had 169

text: AM

text: , 55

text: FM

text: , and 58 TV broadcasting stations. The

text: Cuban Institute of Radio and Television

text: serves as the government’s administrative outlet for broadcasting. Of the six national AM/FM radio networks, the top three are

text: Radio Progreso

text: Radio Reloj

text: , and

text: Radio Rebelde

text: , in that order. Two other national radio networks that also provide news and entertainment are Radio Musical Nacional (CMBF) and Radio Enciclopedia. Another station,

text: Radio Taíno

text: , promotes

text: tourism

text: . The Cuban government also operates

text: Radio Havana

text: , the official Cuban international short-wave radio service. The Cuban television system is made up of two networks: Cubavisión and Tele Rebelde. Cuba’s restriction of foreign broadcast media is one reason the U.S. government has sponsored radio and television broadcasting into Cuba through

text: Radio y Televisión Martí

text: , much of which is jammed.

text: In 1989 URE started taking Capital Radio as its overnight "sustaining" service, when it couldn't provide output. This has been reported to be an innovative piece of programming. At the time Capital was by far the most dominant ILR station in the UK, with highly innovative programming. However, in North Essex, Capital was out of range except for people with a very expensive directional aerial. URE possessed this - and relayed Capital overnight, and for early breakfast until 8am: this considerably drove its listenership, although it took a knock in 1990 when URE's main competition, BBC Radio 1, started broadcasting in FM - previously BBC Radio 1 had been at 1053 & 1089 kHz AM, and for some students switching from FM to AM and back was too complicated, as other Medium Wave stations later also found. Ironically, to celebrate the launch of Radio 1 in FM, Radio 1 toured East Anglia by Helicopter and touched down at the Wivenhoe Park campus: alas, they did so in the middle of the Easter Holidays, and the only people to greet them were members of URE.

text: In 1989 URE started taking

text: Capital Radio

text: as its overnight "sustaining" service, when it couldn't provide output. This has been reported to be an innovative piece of programming. At the time Capital was by far the most dominant ILR station in the UK, with highly innovative programming. However, in North Essex, Capital was out of range except for people with a very expensive directional aerial. URE possessed this - and relayed Capital overnight, and for early breakfast until 8am: this considerably drove its listenership, although it took a knock in 1990 when URE's main competition, BBC Radio 1, started broadcasting in FM - previously BBC Radio 1 had been at 1053 & 1089 kHz AM, and for some students switching from FM to AM and back was too complicated, as other Medium Wave stations later also found. Ironically, to celebrate the launch of Radio 1 in FM, Radio 1 toured East Anglia by Helicopter and touched down at the Wivenhoe Park campus: alas, they did so in the middle of the Easter Holidays, and the only people to greet them were members of URE.

text: Early transmitters emitted damped waves, which were decaying sinewaves at the transmission frequency. Bursts were made at an audible frequency. The damped waves were a result of the available technologies to generate radio frequencies.  See spark gap transmitter.  The transmitters could be keyed on and off to send Morse code.

text: Early transmitters emitted damped waves, which were decaying sinewaves at the transmission frequency. Bursts were made at an audible frequency. The damped waves were a result of the available technologies to generate radio frequencies.  See

text: spark gap transmitter

text: .  The transmitters could be keyed on and off to send Morse code.

text: The monopole is a resonant antenna; the rod functions as an open resonator for radio waves, oscillating with standing waves of voltage and current along its length.  Therefore, the length of the antenna is determined by the wavelength of the radio waves it is used with. The most common or fundamental form is the quarter-wave monopole, in which the antenna is approximately ¼ of the wavelength of the radio waves.  The monopole antenna was invented in 1895 by radio pioneer Guglielmo Marconi; for this reason it is sometimes called the Marconi antenna. Common types of monopole antenna are the whip, rubber ducky, helical, random wire, umbrella, inverted-L and T-antenna, inverted-F, mast radiator, and ground plane antennas.

text: The monopole is a

text: resonant

text: antenna; the rod functions as an open

text: resonator

text: for radio waves, oscillating with

text: standing wave

text: s of voltage and current along its length.  Therefore, the length of the antenna is determined by the

text: wavelength

text: of the radio waves it is used with. The most common or fundamental form is the quarter-wave monopole, in which the antenna is approximately ¼ of the wavelength of the radio waves.  The monopole antenna was invented in 1895 by radio pioneer

text: Guglielmo Marconi

text: ; for this reason it is sometimes called the Marconi antenna. Common types of monopole antenna are the

text: whip

text: rubber ducky

text: helical

text: random wire

text: umbrella

text: , inverted-L and

text: T-antenna

text: inverted-F

text: mast radiator

text: , and

text: ground plane

text: antennas.

text: New York Public Radio (NYPR) is the owner of WNYC (AM), WNYC-FM, WNYC Studios, WQXR-FM, New Jersey Public Radio, and the Jerome L. Greene Performance Space. Combined, New York Public Radio owns WNYC (AM), WNYC-FM, WQXR-FM, WQXW, WNJT-FM, WNJP, WNJY, and WNJO.

text: New York Public Radio (NYPR) is the owner of

text: WNYC (AM)

text: WNYC-FM

text: WNYC Studios

text: WQXR-FM

text: New Jersey Public Radio

text: , and the Jerome L. Greene Performance Space. Combined, New York Public Radio owns

text: WNYC (AM)

text: WNYC-FM

text: WQXR-FM

text: WQXW

text: WNJT-FM

text: WNJP

text: WNJY

text: , and

text: WNJO

text: The color names for these different types of sounds are derived from a loose analogy between the spectrum of frequencies of sound wave present in the sound (as shown in the blue diagrams) and the equivalent spectrum of light wave frequencies. That is, if the sound wave pattern of "blue noise" were translated into light waves, the resulting light would be blue, and so on.

text: The international radio service broadcasts radio programmes in Albanian and seven other languages via medium wave (AM) and short wave (SW). and uses the theme from the song "Këputa një gjethe dafine" as its signature tune. The international television service via satellite was launched in 1993 and is aimed at Albanian-speaking communities in Kosovo, Serbia, Macedonia, Montenegro, and northern Greece, plus the Albanian diaspora in the rest of Europe. Since 1999, RTSH has been a member of the European Broadcasting Union.

text: The international radio service broadcasts radio programmes in Albanian and seven other languages via

text: medium wave

text: (AM) and

text: short wave

text: (SW). and uses the theme from the song "Këputa një gjethe dafine" as its

text: signature tune

text: . The international television service

text: via satellite

text: was launched in 1993 and is aimed at

text: Albanian-speaking

text: communities in

text: Kosovo

text: Serbia

text: Macedonia

text: Montenegro

text: , and northern

text: Greece

text: , plus the Albanian

text: diaspora

text: in the rest of

text: Europe

text: . Since 1999, RTSH has been a member of the

text: European Broadcasting Union

text: After World War II, FM radio broadcasting was introduced in Germany. In 1948, a new wavelength plan was set up for Europe at a meeting in Copenhagen. Because of the recent war, Germany (which did not exist as a state and so was not invited) was only given a small number of medium-wave frequencies, which are not very good for broadcasting. For this reason Germany began broadcasting on UKW ("Ultrakurzwelle", i.e. ultra short wave, nowadays called VHF) which was not covered by the Copenhagen plan. After some amplitude modulation experience with VHF, it was realized that FM radio was a much better alternative for VHF radio than AM. Because of this history FM Radio is still referred to as "UKW Radio" in Germany. Other European nations followed a bit later, when the superior sound quality of FM and the ability to run many more local stations because of the more limited range of VHF broadcasts were realized.

text: After World War II,

text: FM radio

text: broadcasting was introduced in Germany. In 1948, a new wavelength plan was set up for Europe at a meeting in

text: Copenhagen

text: . Because of the recent war, Germany (which did not exist as a state and so was not invited) was only given a small number of

text: medium-wave

text: frequencies, which are not very good for broadcasting. For this reason Germany began broadcasting on UKW ("Ultrakurzwelle", i.e. ultra short wave, nowadays called

text: VHF

text: ) which was not covered by the Copenhagen plan. After some

text: amplitude modulation

text: experience with VHF, it was realized that FM radio was a much better alternative for VHF radio than AM. Because of this history FM Radio is still referred to as "UKW Radio" in Germany. Other European nations followed a bit later, when the superior sound quality of FM and the ability to run many more local stations because of the more limited range of VHF broadcasts were realized.

text: The existing analog AM and FM radio frequencies will be allocated for community and public radio. There are 525 AM and FM channels nationwide.

text: In using the Laplace, Z-, or Fourier transforms, a signal is described by a complex function of frequency: the component of the signal at any given frequency is given by a complex number. The magnitude of the number is the amplitude of that component, and the angle is the relative phase of the wave.  For example, using the Fourier transform a sound wave, such as human speech, can be broken down into its component tones of different frequencies, each represented by a sine wave of a different amplitude and phase.   The response of a system, as a function of frequency, can also be described by a complex function.  In many applications, phase information is not important.  By discarding the phase information it is possible to simplify the information in a frequency domain representation to generate a frequency spectrum or spectral density.     A spectrum analyzer is a device that displays the spectrum, while the time domain frequency can be seen on an oscilloscope.

text: In using the

text: Laplace

text: Z-

text: , or Fourier transforms, a signal is described by a

text: complex function

text: of frequency: the component of the signal at any given frequency is given by a

text: complex number

text: . The

text: magnitude

text: of the number is the

text: amplitude

text: of that component, and the angle is the relative phase of the wave.  For example, using the Fourier transform a

text: sound wave

text: , such as human speech, can be broken down into its component tones of different frequencies, each represented by a sine wave of a different amplitude and phase.   The response of a system, as a function of frequency, can also be described by a complex function.  In many applications, phase information is not important.  By discarding the phase information it is possible to simplify the information in a frequency domain representation to generate a

text: frequency spectrum

text: or

text: spectral density

text: .     A spectrum analyzer is a device that displays the spectrum, while the time domain frequency can be seen on an

text: oscilloscope

text: "AM Only" was created by Transtar Radio Networks at a time when FM had overtaken AM for listeners seeking music on the radio. The format was promoted only to AM stations, though it was not long before some FM stations used it as well.

text: "AM Only" was created by

text: Transtar Radio Networks

text: at a time when

text: FM

text: had overtaken

text: AM

text: for listeners seeking music on the radio. The format was promoted only to AM stations, though it was not long before some FM stations used it as well.

text: The station was formed when Radio Hallam split its FM and medium wave frequencies to provide two separate services. The AM station became "Classic Gold", then "Classic Gold Radio", "Great Yorkshire Gold" and "Great Yorkshire Radio". The original incarnation was owned by The Yorkshire Radio Network who were then taken over by Metro Radio group before being bought by EMAP.

text: The station was formed when

text: Radio Hallam

text: split its

text: FM

text: and

text: medium wave

text: frequencies to provide two separate services. The AM station became "

text: Classic Gold

text: ", then "Classic Gold Radio", "Great Yorkshire Gold" and "Great Yorkshire Radio". The original incarnation was owned by

text: The Yorkshire Radio Network

text: who were then taken over by

text: Metro Radio group

text: before being bought by EMAP.

text: Some microbroadcasters and pirate radio broadcasters, especially those in the United States under the FCC's Part 15 rules, broadcast on AM to achieve greater range than is possible on the FM band. On mediumwave (AM), such radio stations are often found between 1610 kHz and 1710 kHz. Hobbyists also use low-power AM (LPAM) transmitters to provide programming for vintage radio equipment in areas where AM programming is not widely available or does not carry programming the listener desires; in such cases the transmitter, which is designed to cover only the immediate property and perhaps nearby areas, is connected to a computer, an FM radio or an MP3 player. Microbroadcasting and pirate radio have been greatly supplemented by streaming audio on the Internet, but some schools or hobbyists still use LPAM as a means of broadcasting as each are distinctly different technologies.

text: Some

text: microbroadcasters

text: and

text: pirate radio

text: broadcasters, especially those in the United States under the FCC's

text: Part 15

text: rules, broadcast on AM to achieve greater range than is possible on the

text: FM band

text: . On mediumwave (AM), such radio stations are often found between 1610 kHz and 1710 kHz. Hobbyists also use low-power AM (LPAM) transmitters to provide programming for vintage radio equipment in areas where AM programming is not widely available or does not carry programming the listener desires; in such cases the transmitter, which is designed to cover only the immediate property and perhaps nearby areas, is connected to a computer, an FM radio or an MP3 player. Microbroadcasting and pirate radio have been greatly supplemented by streaming audio on the Internet, but some schools or hobbyists still use LPAM as a means of broadcasting as each are distinctly different technologies.

text: In electronics, a Lecher line or Lecher wires is a pair of parallel wires or rods that were used to measure the wavelength of radio waves, mainly at UHF and microwave frequencies.   They form a short length of balanced transmission line (a resonant stub).  When attached to a source of radio-frequency power such as a radio transmitter, the radio waves form standing waves along their length.  By sliding a conductive bar that bridges the two wires along their length, the length of the waves can be physically measured.  Austrian physicist Ernst Lecher, improving on techniques used by Oliver Lodge and Heinrich Hertz, developed this method of measuring wavelength around 1888.  Lecher lines were used as frequency measuring devices until frequency counters became available after World War 2.  They were also used as components, often called "resonant stubs", in UHF and microwave radio equipment such as transmitters, radar sets, and television sets, serving as tank circuits, filters, and impedance-matching devices.  They are used at frequencies between HF/VHF, where lumped components are used, and UHF/SHF, where resonant cavities are more practical.

text: In

text: electronics

text: , a Lecher line or Lecher wires is a pair of parallel wires or rods that were used to measure the

text: wavelength

text: of

text: radio wave

text: s, mainly at

text: UHF

text: and

text: microwave

text: frequencies

text: .   They form a short length of

text: balanced

text: transmission line

text: (a

text: resonant stub

text: ).  When attached to a source of

text: radio-frequency

text: power such as a radio transmitter, the radio waves form

text: standing wave

text: s along their length.  By sliding a conductive bar that bridges the two wires along their length, the length of the waves can be physically measured.  Austrian physicist

text: Ernst Lecher

text: , improving on techniques used by

text: Oliver Lodge

text: and

text: Heinrich Hertz

text: , developed this method of measuring wavelength around 1888.  Lecher lines were used as frequency measuring devices until

text: frequency counter

text: s became available after World War 2.  They were also used as

text: components

text: , often called "

text: resonant stubs

text: ", in UHF and

text: microwave

text: radio equipment such as

text: transmitter

text: s,

text: radar

text: sets, and

text: television set

text: s, serving as

text: tank circuits

text: filters

text: , and impedance-matching devices.  They are used at frequencies between

text: HF

text: VHF

text: , where

text: lumped

text: components are used, and

text: UHF

text: SHF

text: , where

text: resonant cavities

text: are more practical.

text: BBC Radio 5 Live broadcasts in AM on the medium wave frequencies 693 and 909 kHz nationally, with the frequency 990 kHz used at Cardigan Bay; these frequencies had been utilised by BBC Radio 5 and were used by BBC Radio 2 previously. Uniquely to the BBC Radio network, it is the only station that is neither purely digital (such as 1Xtra, Radio 4 Extra and 6 Music) nor broadcast in analogue FM. In addition to the AM output, the station also broadcasts digitally on DAB Digital Radio, and on television through satellite services such as Sky, cable services such as Virgin Media, DTT services such as Freeview and through IPTV. The station also broadcasts programmes live through the BBC Online website and the BBC iPlayer sub-site, which allows replaying programmes up to a week after the original broadcast. The service is also available on the Radioplayer internet site partially run by the BBC. Before the launch of digital broadcasting, BBC Radio 5 Live had broadcast on analogue satellite with near-FM quality.

text: BBC Radio 5 Live broadcasts in

text: AM

text: on the

text: medium wave

text: frequencies 693 and 909 kHz nationally, with the frequency 990 kHz used at

text: Cardigan Bay

text: ; these frequencies had been utilised by BBC Radio 5 and were used by

text: BBC Radio 2

text: previously. Uniquely to the

text: BBC Radio

text: network, it is the only station that is neither purely digital (such as

text: Radio 4 Extra

text: and

text: 6 Music

text: ) nor broadcast in analogue

text: FM

text: . In addition to the AM output, the station also broadcasts digitally on

text: DAB Digital Radio

text: , and on television through

text: satellite

text: services such as

text: Sky

text: cable

text: services such as

text: Virgin Media

text: DTT

text: services such as

text: Freeview

text: and through

text: IPTV

text: . The station also broadcasts programmes live through the

text: BBC Online

text: website and the

text: BBC iPlayer

text: sub-site, which allows replaying programmes up to a week after the original broadcast. The service is also available on the

text: Radioplayer

text: internet site partially run by the BBC. Before the launch of digital broadcasting, BBC Radio 5 Live had broadcast on analogue satellite with near-FM quality.

text: Broadcast Wave Format (BWF) is an extension of the popular Microsoft WAVE audio format and is the recording format of most file-based non-linear digital recorders used for motion picture, radio and television production.

text: Broadcast Wave Format (BWF) is an extension of the popular

text: Microsoft WAVE

text: audio format and is the recording format of most file-based

text: non-linear

text: digital recorders

text: used for

text: motion picture

text: , radio and

text: television

text: production

text: Radio waves can be made to carry information by varying a combination of the amplitude, frequency, and phase of the wave within a frequency band. When EM radiation impinges upon a conductor, it couples to the conductor, travels along it, and induces an electric current on the surface of that conductor by exciting the electrons of the conducting material. This effect (the skin effect) is used in antennas.

text: Radio waves can be made to carry information by varying a combination of the amplitude, frequency, and phase of the wave within a frequency band. When EM radiation impinges upon a

text: conductor

text: , it couples to the conductor, travels along it, and

text: induces

text: an electric current on the surface of that conductor by exciting the electrons of the conducting material. This effect (the

text: skin effect

text: ) is used in antennas.

text: BBC Radio Scotland was founded as a full-time radio network on 23 November 1978. Previously it was possible only to opt out of Radio 4, and the service was known as Radio 4 Scotland or, formally on air, as "BBC Scotland Radio 4".  The establishment of a separate network was made possible when Radio 4 became a fully UK-wide network and moved from medium wave to long wave and new VHF (FM) transmitters were brought into service so that Radio 4 and Radio Scotland no longer had to share on FM.

text: BBC Radio Scotland was founded as a full-time radio network on 23 November 1978. Previously it was possible only to opt out of Radio 4, and the service was known as Radio 4 Scotland or, formally on air, as "BBC Scotland Radio 4".  The establishment of a separate network was made possible when Radio 4 became a fully UK-wide network and moved from

text: medium wave

text: to

text: long wave

text: and new VHF (FM) transmitters were brought into service so that Radio 4 and Radio Scotland no longer had to share on FM.

text: On December 10, 1987,  J-WAVE was incorporated and started test broadcasts on the FM band at 81.3 MHz on August 1, 1988. On October 1 of that year at 5:00 am, it started transmission from Tokyo Tower. J-Wave was the 27th FM radio station nationwide to launch at that time, and the second in Tokyo. While other radio stations focused more on presentation, J-WAVE adopted a "more music less talk" format. The station had a large fanbase because of its unusual programming style, playing music non-stop except for jingles and breaks for news, traffic and weather. The law in Japan at that time stipulated that programming had to be maximum 80% music, and minimum 20% talk and continuity. J-WAVE coined the term "J-pop", which is only vaguely defined. However, as the years went by, the station lost influence. Sponsor after sponsor pulled their ads because of the growing irrelevance of the programming to what they were selling.

text: On December 10, 1987,  J-WAVE was incorporated and started test broadcasts on the FM band at 81.3 MHz on August 1, 1988. On October 1 of that year at 5:00 am, it started transmission from

text: Tokyo Tower

text: . J-Wave was the 27th FM radio station nationwide to launch at that time, and the second in Tokyo. While other radio stations focused more on presentation, J-WAVE adopted a "more music less talk" format. The station had a large fanbase because of its unusual programming style, playing music non-stop except for jingles and breaks for news, traffic and weather. The law in Japan at that time stipulated that programming had to be maximum 80% music, and minimum 20% talk and continuity. J-WAVE coined the term "

text: J-pop

text: ", which is only vaguely defined. However, as the years went by, the station lost influence. Sponsor after sponsor pulled their ads because of the growing irrelevance of the programming to what they were selling.

text: The medium-wave band is used worldwide for AM broadcasting. Europe also uses the long wave band. In response to the growing popularity of FM stereo radio stations in the late 1980s and early 1990s, some North American stations began broadcasting in AM stereo, though this never gained popularity, and very few receivers were ever sold.

text: The medium-wave band is used worldwide for AM broadcasting. Europe also uses the

text: long wave

text: band. In response to the growing popularity of

text: FM stereo

text: radio stations in the late 1980s and early 1990s, some

text: North America

text: n stations began broadcasting in

text: AM stereo

text: , though this never gained popularity, and very few receivers were ever sold.

text: In March 1953, Picture Waves sold WTVN to Radio Cincinnati, Inc., the broadcasting interests of the Taft family of Cincinnati.  Radio Cincinnati would later become the Taft Broadcasting Company.  The following year, Radio Cincinnati purchased WHKC radio (610 AM) from the publishers of the Cleveland Plain Dealer, renaming that station WTVN (AM) and subsequently adding a -TV suffix to channel 6's call sign.  Taft would launch a second radio station in Columbus, WTVN-FM (96.3 FM, now WLVQ), in April 1960.

text: In March 1953, Picture Waves sold WTVN to Radio Cincinnati, Inc., the broadcasting interests of the

text: Taft family

text: of

text: Cincinnati

text: .  Radio Cincinnati would later become the

text: Taft Broadcasting Company

text: .  The following year, Radio Cincinnati purchased WHKC radio (610 AM) from the publishers of the

text: Cleveland Plain Dealer

text: , renaming that station

text: WTVN (AM)

text: and subsequently adding a -TV suffix to channel 6's call sign.  Taft would launch a second radio station in Columbus, WTVN-FM (96.3 FM, now

text: WLVQ

text: ), in April 1960.

text: On the longer term, after accomplishing the primary goal of discovering gravitational waves, Virgo aims at being part of the birth of a new branch of astronomy by observing the Universe with a different and complementary perspective than current telescopes and detectors. Information brought by gravitational waves will be added to those provided by the study of the electromagnetic spectrum (microwaves, radio waves, infrared, the visible spectrum, ultraviolet, X rays and gamma rays), of cosmic rays and of neutrinos. In order to correlate a gravitational wave detection with visible and localized events in the sky, the LIGO and VIRGO collaborations have signed bilateral agreements with many teams operating telescopes to quickly inform (on the timescale of a few days or a few hours) these partners that a potential gravitational wave signal has been observed. These alerts must be sent before knowing whether the signal is real or not, because the source (if it is real) may only remain visible during a short amount of time.

text: On the longer term, after accomplishing the primary goal of discovering gravitational waves, Virgo aims at being part of the birth of a new branch of astronomy by observing the Universe with a different and complementary perspective than current telescopes and detectors. Information brought by gravitational waves will be added to those provided by the study of the electromagnetic spectrum (

text: microwave

text: s,

text: radio wave

text: s,

text: infrared

text: the visible spectrum

text: ultraviolet

text: X rays

text: and

text: gamma ray

text: s), of

text: cosmic ray

text: s and of

text: neutrino

text: s. In order to correlate a gravitational wave detection with visible and localized events in the sky, the LIGO and VIRGO collaborations have signed bilateral agreements with many teams operating telescopes to quickly inform (on the timescale of a few days or a few hours) these partners that a potential gravitational wave signal has been observed. These alerts must be sent before knowing whether the signal is real or not, because the source (if it is real) may only remain visible during a short amount of time.

text: XHZS-FM/XEZS-AM is a combo radio station in Coatzacoalcos, Veracruz. Broadcasting on 92.3 FM and 1170 AM, XHZS/XEZS is known as Radio Hit.

text: XHZS-FM/XEZS-AM is a combo radio station in

text: Coatzacoalcos, Veracruz

text: . Broadcasting on 92.3 FM and 1170 AM, XHZS/XEZS is known as Radio Hit.

text: Fresh Radio was a local radio station broadcasting to the Yorkshire Dales in northern England on two medium wave (AM) frequencies and three FM frequencies.  It was also heard online via the Fresh Radio website.

text: Fresh Radio was a local radio station broadcasting to the

text: Yorkshire Dales

text: in northern England on two medium wave (AM) frequencies and three FM frequencies.  It was also heard online via the Fresh Radio website.

text: XEHZ-AM/XHHZ-FM (990 AM/105.5 FM, "Radio HZ") is a Mexican radio station that serves the area around La Paz, Baja California Sur.

text: XEHZ-AM/XHHZ-FM (990

text: AM

text: /105.5 FM, "Radio HZ") is a

text: Mexican

text: radio station

text: that serves the area around

text: La Paz, Baja California Sur

text: When a radio wave reaches the ionosphere, the electric field in the wave forces the electrons in the ionosphere into oscillation at the same frequency as the radio wave. Some of the radio-frequency energy is given up to this resonant oscillation. The oscillating electrons will then either be lost to recombination or will re-radiate the original wave energy. Total refraction can occur when the collision frequency of the ionosphere is less than the radio frequency, and if the electron density in the ionosphere is great enough.

text: When a radio wave reaches the ionosphere, the

text: electric field

text: in the wave forces the electrons in the ionosphere into

text: oscillation

text: at the same frequency as the radio wave. Some of the radio-frequency energy is given up to this resonant oscillation. The oscillating electrons will then either be lost to recombination or will re-radiate the original wave energy. Total refraction can occur when the collision frequency of the ionosphere is less than the radio frequency, and if the electron density in the ionosphere is great enough.

text: The ionosphere bends radio waves in the same manner that water in a swimming pool bends visible light. When the medium through which such waves travel is disturbed, the light image or radio information is distorted and can become unrecognizable. The degree of distortion (scintillation) of a radio wave by the ionosphere depends on the signal frequency. Radio signals in the VHF band (30 to 300 MHz) can be distorted beyond recognition by a disturbed ionosphere. Radio signals in the UHF band (300 MHz to 3 GHz) transit a disturbed ionosphere, but a receiver may not be able to keep locked to the carrier frequency. GPS uses signals at 1575.42 MHz (L1) and 1227.6 MHz (L2) that can be distorted by a disturbed ionosphere. Space weather events that corrupt GPS signals can significantly impact society. For example, the Wide Area Augmentation System (WAAS) operated by the US Federal Aviation Administration is used as a navigation tool for North American commercial aviation. It is disabled by every major space weather event. Outages can range from minutes to days. Major space weather events can push the disturbed polar ionosphere 10° to 30° of latitude toward the equator and can cause large ionospheric gradients (changes in density over distance of hundreds of km) at mid and low latitude. Both of these factors can distort GPS signals.

text: The

text: ionosphere

text: bends radio waves in the same manner that water in a swimming pool bends visible light. When the medium through which such waves travel is disturbed, the light image or radio information is distorted and can become unrecognizable. The degree of distortion (scintillation) of a radio wave by the ionosphere depends on the signal frequency. Radio signals in the

text: VHF

text: band (30 to 300 MHz) can be distorted beyond recognition by a disturbed ionosphere. Radio signals in the

text: UHF

text: band (300 MHz to 3 GHz) transit a disturbed ionosphere, but a receiver may not be able to keep locked to the carrier frequency. GPS uses signals at 1575.42 MHz (L1) and 1227.6 MHz (L2) that can be distorted by a disturbed ionosphere. Space weather events that corrupt GPS signals can significantly impact society. For example, the

text: Wide Area Augmentation System

text: (WAAS) operated by the US

text: Federal Aviation Administration

text: is used as a navigation tool for North American commercial aviation. It is disabled by every major space weather event. Outages can range from minutes to days. Major space weather events can push the disturbed polar ionosphere 10° to 30° of latitude toward the equator and can cause large ionospheric gradients (changes in density over distance of hundreds of km) at mid and low latitude. Both of these factors can distort GPS signals.

text: Whereas the sea state in the storm has a frequency spectrum with more or less always the same shape (i.e. a well defined peak with dominant frequencies within plus or minus 7% of the peak), the swell spectra are more and more narrow, sometimes as 2% or less, as waves disperse further and further away. The result is that wave groups (called sets by surfers) can have a large number of waves.  From about seven waves per group in the storm, this rises to 20 and more in swells from very distant storms.

text: Whereas the sea state in the storm has a

text: frequency spectrum

text: with more or less always the same shape (i.e. a well defined peak with dominant frequencies within plus or minus 7% of the peak), the swell spectra are more and more narrow, sometimes as 2% or less, as waves disperse further and further away. The result is that wave groups (called sets by surfers) can have a large number of waves.  From about seven waves per group in the storm, this rises to 20 and more in swells from very distant storms.

text: XERFR-AM/FM (970 AM/103.3 FM) is a radio station in Mexico City. It is the flagship of Radio Fórmula's Primera Cadena.

text: XERFR-AM/FM (

text: 970 AM

text: 103.3 FM

text: ) is a radio station in

text: Mexico City

text: . It is the flagship of

text: Radio Fórmula

text: 's Primera Cadena.

text: Orion merged with The Liberty Corporation in 1981. WAVE-TV then became part of Liberty's broadcast arm, Cosmos Broadcasting. WAVE radio was then sold off; the WAVE cluster had been grandfathered when the FCC banned common ownership of radio and television stations in the same market in the 1960s, but lost its grandfathered protection with the Liberty merger. As the radio station promptly changed its call sign to WAVG, Cosmos dropped the "-TV" suffix from the WAVE callsign in 1987. In 1991, the station began transmitting its signal from a new broadcast tower in Oldham County; the  transmitter tower (which is 70% taller than most television broadcast towers), which is the tallest structure in the state, cost $5 million to build and helped to improve WAVE's signal coverage. When the Liberty Corporation exited from the insurance industry in 2000, WAVE came directly under the Liberty banner; in August 2005, Liberty announced that it would merg with the Montgomery, Alabama-based Raycom Media; the sale was finalized on January 31, 2006.

text: Orion merged with

text: The Liberty Corporation

text: in 1981. WAVE-TV then became part of Liberty's broadcast arm, Cosmos Broadcasting. WAVE radio was then sold off; the WAVE cluster had been

text: grandfathered

text: when the FCC banned common ownership of radio and television stations in the same market in the 1960s, but lost its grandfathered protection with the Liberty merger. As the radio station promptly changed its call sign to WAVG, Cosmos dropped the "-TV" suffix from the WAVE callsign in 1987. In 1991, the station began transmitting its signal from a new broadcast tower in

text: Oldham County

text: ; the  transmitter tower (which is 70% taller than most television broadcast towers), which is the tallest structure in the state, cost $5 million to build and helped to improve WAVE's signal coverage. When the Liberty Corporation exited from the insurance industry in 2000, WAVE came directly under the Liberty banner; in August 2005, Liberty announced that it would merg with the

text: Montgomery, Alabama

text: -based

text: Raycom Media

text: ; the sale was finalized on January 31, 2006.

text: Assuming a sinusoidal wave moving at a fixed wave speed, wavelength is inversely proportional to frequency of the wave: waves with higher frequencies have shorter wavelengths, and lower frequencies have longer wavelengths.

text: Assuming a sinusoidal wave moving at a fixed wave speed, wavelength is inversely proportional to

text: frequency

text: of the wave: waves with higher frequencies have shorter wavelengths, and lower frequencies have longer wavelengths.

text: An atmospheric wave is a periodic disturbance in the fields of atmospheric variables (like surface pressure or geopotential height, temperature, or wind velocity) which may either propagate (traveling wave) or not (standing wave). Atmospheric waves range in spatial and temporal scale from large-scale planetary waves (Rossby waves) to minute sound waves. Atmospheric waves with periods which are harmonics of 1 solar day (e.g. 24 hours, 12 hours, 8 hours... etc.) are known as atmospheric tides.

text: An atmospheric wave is a periodic disturbance in the fields of

text: atmospheric

text: variables (like

text: surface pressure

text: or

text: geopotential height

text: temperature

text: , or

text: wind velocity

text: ) which may either propagate (

text: traveling wave

text: ) or not (

text: standing wave

text: ). Atmospheric waves range in

text: spatial

text: and

text: temporal

text: scale from large-scale planetary waves (

text: Rossby wave

text: s) to minute

text: sound wave

text: s. Atmospheric waves with periods which are

text: harmonics

text: of 1

text: solar day

text: (e.g. 24 hours, 12 hours, 8 hours... etc.) are known as

text: atmospheric tide

text: s.

text: In the 2011 UK Open, Nicholson defeated Phil Taylor in the last 16 by 9 legs to 8 and supposedly waved goodbye to him. While being interviewed at that year's World Matchplay, Nicholson spoke of Taylor's reaction and stated that when they met again, if Taylor did not bring his 'A' game he would "put him to bed". Nicholson defended the gesture saying: 'I was waving bye-bye to the demons which had dogged me in too many televised tournaments'. The comments garnered much media attention.Taylor reacted angrily to Nicholson's comments, telling BBC Radio Stoke, "I think he's very, very silly." Taylor added that Nicholson "has a big mouth and won't keep it shut". He played Taylor in an eagerly anticipated match at the 2011 European Darts Championships and was beaten 10-7, despite being 7-6 ahead.  He was then defeated at the 2011 World Grand Prix by Taylor 3-0.

text: In the

text: 2011 UK Open

text: , Nicholson defeated Phil Taylor in the last 16 by 9 legs to 8 and supposedly waved goodbye to him. While being interviewed at that year's

text: World Matchplay

text: , Nicholson spoke of Taylor's reaction and stated that when they met again, if Taylor did not bring his 'A' game he would "put him to bed". Nicholson defended the gesture saying: 'I was waving bye-bye to the demons which had dogged me in too many televised tournaments'. The comments garnered much media attention.Taylor reacted angrily to Nicholson's comments, telling

text: BBC Radio Stoke

text: , "I think he's very, very silly." Taylor added that Nicholson "has a big mouth and won't keep it shut". He played Taylor in an eagerly anticipated match at the

text: 2011 European Darts Championships

text: and was beaten 10-7, despite being 7-6 ahead.  He was then defeated at the

text: 2011 World Grand Prix

text: by Taylor 3-0.

text: ELF waves can also travel considerable distances through "lossy" media like earth and seawater, which would absorb higher frequency radio waves.

text: Early FM broadcasting in North America originally used the 42–50 MHz band (this range was also used by a class of experimental wideband AM stations known as apex broadcasters). In 1941, the Yankee Network, which was already using FM for AM station feeds, started operating a station, W39B, in this band from a transmitter atop Mount Washington, New Hampshire, the highest point in the northeast United States. (Studios were in Boston.) In 1945 the United States FCC decided to move FM broadcasters to the 88.1–105.9 MHz band (later extended to 107.9 MHz); this made all the existing FM radios useless, although converters could be purchased. It was even more expensive for broadcasters to rebuild their transmitters to work on the new band. Altogether, the change set FM radio back ten years.

text: Early FM broadcasting in North America originally used the 42–50 MHz band (this range was also used by a class of experimental wideband AM stations known as

text: apex broadcasters

text: ). In 1941, the

text: Yankee Network

text: , which was already using FM for AM station

text: feeds

text: , started operating a station,

text: , in this band from a transmitter atop

text: Mount Washington

text: New Hampshire

text: , the highest point in the northeast United States. (Studios were in Boston.) In 1945 the United States

text: FCC

text: decided to move FM broadcasters to the 88.1–105.9 MHz band (later extended to 107.9 MHz); this made all the existing FM radios useless, although converters could be purchased. It was even more expensive for broadcasters to rebuild their transmitters to work on the new band. Altogether, the change set FM radio back ten years.

text: TMS became a fixture on BBC Radio 3 on AM medium wave until Radio 3 lost its MW frequency in February 1992. The programme moved to Radio 3 FM that summer and the following summer the morning play was on Radio 5, switching to Radio 3 for the afternoon session. The start of Radio 5 Live meant that TMS moved to its present home on Radio 4 long wave (198 LW, plus various localised MW frequencies including 720 MW in London and 603 MW in the North East). At times of cricket matches, the normal BBC Radio 4 schedule continues on its FM frequencies, whilst longwave is taken over by the cricket.

text: TMS became a fixture on BBC Radio 3 on AM

text: medium wave

text: until Radio 3 lost its MW frequency in February 1992. The programme moved to Radio 3 FM that summer and the following summer the morning play was on Radio 5, switching to Radio 3 for the afternoon session. The start of Radio 5 Live meant that TMS moved to its present home on Radio 4 long wave (198 LW, plus various localised MW frequencies including 720 MW in London and 603 MW in the North East). At times of cricket matches, the normal

text: BBC Radio 4

text: schedule continues on its

text: FM

text: frequencies, whilst

text: longwave

text: is taken over by the cricket.

text: In physics, interference is a phenomenon in which two waves superpose to form a resultant wave of greater, lower, or the same amplitude. Interference usually refers to the interaction of waves that are correlated or coherent with each other, either because they come from the same source or because they have the same or nearly the same frequency. Interference effects can be observed with all types of waves, for example, light, radio, acoustic, surface water waves or matter waves.

text: In

text: physics

text: , interference is a phenomenon in which two

text: wave

text: s

text: superpose

text: to form a resultant wave of greater, lower, or the same

text: amplitude

text: . Interference usually refers to the interaction of waves that are correlated or

text: coherent

text: with each other, either because they come from the same source or because they have the same or nearly the same

text: frequency

text: . Interference effects can be observed with all types of waves, for example,

text: light

text: radio

text: acoustic

text: surface water wave

text: s or

text: matter wave

text: s.

text: SBC operates a television network and an AM radio station at 1368 kHz (219 metres) on medium wave.  These broadcast programmes in the three national languages: English, French and Seychellois Creole. SBC also operates Paradise FM, a 24-hours Music radio station.

text: SBC operates a

text: television

text: network and an

text: AM

text: radio station at 1368 kHz (219 metres) on medium wave.  These broadcast programmes in the three national languages:

text: English

text: French

text: and

text: Seychellois Creole

text: . SBC also operates Paradise FM, a 24-hours

text: Music radio

text: station.

text: Swazi Music Radio (SMR) was a South African radio station broadcasting from Swaziland between 1972 and 1978. It was initially established as Swaziland Commercial Radio but was soon taken over by the South African entrepreneurs Issie and Natie Kirsh as a competitor to LM Radio which broadcast from nearby Mozambique. The studios were based in central Johannesburg and the transmitters were in Sandlane in Swaziland, just across the eastern border of South Africa, not far from the small town of Amsterdam. Programmes were recorded in Johannesburg and the tapes taken by road to the transmitting station for broadcast the next day. It had been hoped that the medium wave transmission would reach the Johannesburg area during the day, however long distance medium wave propagation in the former Transvaal Province was poor and only really effective at night. Daytime listening was on short wave. During the years it operated, SMR recruited many of the announcers who had been on LM Radio and SABC stations, among them Gary Edwards, Frank Sanders, John Berks, Darryl Jooste, Leon Fourie, Barry O'Dee and Gordon Hoffman. Another former LM radio announcer George Wayne also returned briefly from Australia to join the station. (Stan Katz, who later went on to become one of South Africa's most prominent broadcasters, joined the station in its early days as a junior programming assistant). Overall, SMR was not commercially successful as it could not compete with the superior technical transmission of Radio 5 (now 5FM) which took over from LM Radio when that station closed in October 1975 and relocated from Mozambique to South Africa. Operated by the South African Broadcasting Corporation, Radio 5 was heard via local medium wave transmitters in all the major cities in South Africa and also had good short wave coverage. When SMR eventually closed, the studios and transmitters were used to broadcast three ethnic radio services - Radio SR, targeted to the black African market, Radio Paralello 27 which broadcast in Portuguese and Radio Truro aimed at the Indian population of South Africa under the direction of radio veterans Rob Vickers and Zena Watkins. These stations all closed down in the 1980s.

text: Swazi Music Radio (SMR) was a

text: South Africa

text: n

text: radio station

text: broadcasting from

text: Swaziland

text: between 1972 and 1978. It was initially established as Swaziland Commercial Radio but was soon taken over by the South African entrepreneurs Issie and Natie Kirsh as a competitor to

text: LM Radio

text: which broadcast from nearby Mozambique. The studios were based in central

text: Johannesburg

text: and the transmitters were in

text: Sandlane

text: in Swaziland, just across the eastern border of South Africa, not far from the small town of Amsterdam. Programmes were recorded in Johannesburg and the tapes taken by road to the transmitting station for broadcast the next day. It had been hoped that the

text: medium wave

text: transmission would reach the Johannesburg area during the day, however long distance medium wave propagation in the former

text: Transvaal Province

text: was poor and only really effective at night. Daytime listening was on

text: short wave

text: . During the years it operated, SMR recruited many of the announcers who had been on

text: LM Radio

text: and SABC stations, among them Gary Edwards, Frank Sanders, John Berks, Darryl Jooste, Leon Fourie, Barry O'Dee and Gordon Hoffman. Another former LM radio announcer George Wayne also returned briefly from Australia to join the station. (Stan Katz, who later went on to become one of South Africa's most prominent broadcasters, joined the station in its early days as a junior programming assistant). Overall, SMR was not commercially successful as it could not compete with the superior technical transmission of Radio 5 (now

text: ) which took over from LM Radio when that station closed in October 1975 and relocated from Mozambique to South Africa. Operated by the South African Broadcasting Corporation, Radio 5 was heard via local medium wave transmitters in all the major cities in South Africa and also had good short wave coverage. When SMR eventually closed, the studios and transmitters were used to broadcast three ethnic radio services - Radio SR, targeted to the

text: black

text: African market, Radio Paralello 27 which broadcast in

text: Portuguese

text: and Radio Truro aimed at the

text: Indian

text: population of South Africa under the direction of radio veterans Rob Vickers and Zena Watkins. These stations all closed down in the 1980s.

text: Fessenden was a significant figure in the development of AM radio.  He was one of the first researchers to realize, from experiments like the above, that the existing technology for producing radio waves, the spark transmitter, was not usable for amplitude modulation, and that a new kind of transmitter, one that produced sinusoidal continuous waves, was needed.  This was a radical idea at the time, because experts believed the impulsive spark was necessary to produce radio frequency waves, and Fessenden was ridiculed.   He invented and helped develop one of the first continuous wave transmitters - the Alexanderson alternator, with which he made what is considered the first AM public entertainment broadcast on Christmas Eve, 1906.  He also discovered the principle on which AM modulation is based, heterodyning, and invented one of the first detectors able to rectify and receive AM, the electrolytic detector or "liquid baretter", in 1902.  Other radio detectors invented for wireless telegraphy, such as the Fleming valve (1904) and the crystal detector (1906) also proved able to rectify AM signals, so the technological hurdle was generating AM waves; receiving them was not a problem.

text: Fessenden was a significant figure in the development of AM radio.  He was one of the first researchers to realize, from experiments like the above, that the existing technology for producing radio waves, the spark transmitter, was not usable for amplitude modulation, and that a new kind of transmitter, one that produced

text: sinusoidal

text: continuous wave

text: s, was needed.  This was a radical idea at the time, because experts believed the impulsive spark was necessary to produce radio frequency waves, and Fessenden was ridiculed.   He invented and helped develop one of the first continuous wave transmitters - the

text: Alexanderson alternator

text: , with which he made what is considered the first AM public entertainment broadcast on Christmas Eve, 1906.  He also discovered the principle on which AM modulation is based,

text: heterodyning

text: , and invented one of the first

text: detector

text: s able to

text: rectify

text: and receive AM, the electrolytic detector or "liquid baretter", in 1902.  Other radio detectors invented for wireless telegraphy, such as the

text: Fleming valve

text: (1904) and the

text: crystal detector

text: (1906) also proved able to rectify AM signals, so the technological hurdle was generating AM waves; receiving them was not a problem.

text: The distribution of frequency and power of a waveform can be expressed as a power spectrum in which the contribution of different waveform frequencies to the waveform under analysis is measured. This can be expressed as either the dominant or peak frequency, i.e., the frequency with the greatest power or the median frequency, which divides the spectrum in two halves.

text: Early radio telegraphy had used long wave transmissions. The drawbacks to this system included a very limited spectrum available for long distance communication, and the very expensive transmitters, receivers and gigantic antennas that were required. It was also difficult to beam the radio wave directionally with long wave, resulting in a major loss of power over long distances.  Prior to the 1920s, the shortwave frequencies above 1.5 MHz were regarded as useless for long distance communication and were designated in many countries for amateur use.

text: Early

text: radio telegraphy

text: had used

text: long wave

text: transmissions. The drawbacks to this system included a very limited spectrum available for long distance communication, and the very expensive

text: transmitter

text: s, receivers and gigantic antennas that were required. It was also difficult to beam the radio wave directionally with long wave, resulting in a major loss of power over long distances.  Prior to the 1920s, the shortwave frequencies above 1.5 MHz were regarded as useless for long distance communication and were designated in many countries for amateur use.

text: Very high frequency (VHF) is the ITU designation for the range of radio frequency electromagnetic waves (radio waves) from  to , with corresponding wavelengths of ten to one meters. Frequencies immediately below VHF are denoted high frequency (HF), and the next higher frequencies are known as ultra high frequency (UHF).

text: Very high frequency (VHF) is the

text: ITU

text: designation for the range of

text: radio frequency

text: electromagnetic wave

text: s (

text: radio wave

text: s) from  to , with corresponding wavelengths of ten to one meters. Frequencies immediately below VHF are denoted

text: high frequency

text: (HF), and the next higher frequencies are known as

text: ultra high frequency

text: (UHF).

text: This unification, which was observed by Michael Faraday, extended by James Clerk Maxwell, and partially reformulated by Oliver Heaviside and Heinrich Hertz, is one of the key accomplishments of 19th century mathematical physics. It has had far-reaching consequences, one of which was the understanding of the nature of light. Unlike what was proposed by electromagnetic theory of that time, light and other electromagnetic waves are at present seen as taking the form of quantized, self-propagating oscillatory electromagnetic field disturbances called photons. Different frequencies of oscillation give rise to the different forms of electromagnetic radiation, from radio waves at the lowest frequencies, to visible light at intermediate frequencies, to gamma rays at the highest frequencies.

text: This unification, which was observed by

text: Michael Faraday

text: , extended by

text: James Clerk Maxwell

text: , and partially reformulated by

text: Oliver Heaviside

text: and

text: Heinrich Hertz

text: , is one of the key accomplishments of 19th century

text: mathematical physics

text: . It has had far-reaching consequences, one of which was the understanding of the nature of

text: light

text: . Unlike what was proposed by electromagnetic theory of that time, light and other

text: electromagnetic waves

text: are at present seen as taking the form of

text: quantized

text: , self-propagating

text: oscillatory

text: electromagnetic field disturbances called

text: photon

text: s. Different

text: frequencies

text: of oscillation give rise to the different forms of

text: electromagnetic radiation

text: , from

text: radio wave

text: s at the lowest frequencies, to visible light at intermediate frequencies, to

text: gamma ray

text: s at the highest frequencies.

text: Few if any television or radio dramas have been set in Middlesbrough.  Episodes of this drama contain references to local streets and landmarks, such as Parliament Road, the Newport Bridge and "Over the Border", a local reference to the oldest part of the town which, for a time, was notorious for prostitution and crime.  The "Border" is generally taken to be the railway tracks which are the southern boundary of the old town, the other boundary being the River Tees. There are also references in Making Waves to the local Teesside "delicacy", the Parmesan.

text: Few if any television or radio dramas have been set in Middlesbrough.  Episodes of this drama contain references to local streets and landmarks, such as Parliament Road, the

text: Newport Bridge

text: and "Over the Border", a local reference to the oldest part of the town which, for a time, was notorious for prostitution and crime.  The "Border" is generally taken to be the railway tracks which are the southern boundary of the old town, the other boundary being the

text: River Tees

text: . There are also references in

text: Making Waves

text: to the local Teesside "delicacy", the

text: Parmesan

text: Unlike the existing radio transmitter of the time, the spark-gap transmitter, the arc converter produces undamped or continuous waves (CW). This was an important feature as the use of damped waves resulted in lower transmitter efficiency and communications effectiveness, while covering the RF spectrum with interference. This more refined method for generating continuous-wave radio signals was initially developed by Danish inventor Valdemar Poulsen.

text: Unlike the existing

text: radio transmitter

text: of the time, the

text: spark-gap transmitter

text: , the arc converter produces undamped or

text: continuous wave

text: s (CW). This was an important feature as the use of

text: damped wave

text: s resulted in lower transmitter efficiency and communications effectiveness, while covering the RF spectrum with interference. This more refined method for generating continuous-wave radio signals was initially developed by Danish inventor

text: Valdemar Poulsen

text: FM broadcast radio sends music and voice with less noise than AM radio. It is often mistakenly thought that FM is higher fidelity than AM, but that is not true. AM is capable of the same audio bandwidth that FM employs. AM receivers typically use narrower filters in the receiver to recover the signal with less noise. AM stereo receivers can reproduce the same audio bandwidth that FM does due to the wider filter used in an AM stereo receiver, but today, AM radios limit the audio bandpass to 3–5 kHz. In frequency modulation, amplitude variation at the microphone causes the transmitter frequency to fluctuate. Because the audio signal modulates the frequency and not the amplitude, an FM signal is not subject to static and interference in the same way as AM signals. Due to its need for a wider bandwidth, FM is transmitted in the Very High Frequency (VHF, 30 MHz to 300 MHz) radio spectrum.

text: FM broadcast radio sends music and voice with less noise than AM radio. It is often mistakenly thought that FM is higher fidelity than AM, but that is not true. AM is capable of the same audio bandwidth that FM employs. AM receivers typically use narrower filters in the receiver to recover the signal with less noise. AM stereo receivers can reproduce the same audio bandwidth that FM does due to the wider filter used in an AM stereo receiver, but today, AM radios limit the audio bandpass to 3–5 kHz. In frequency modulation, amplitude variation at the

text: microphone

text: causes the transmitter frequency to fluctuate. Because the audio signal modulates the frequency and not the amplitude, an FM signal is not subject to static and interference in the same way as AM signals. Due to its need for a wider bandwidth, FM is transmitted in the Very High Frequency (VHF, 30 MHz to 300 MHz) radio spectrum.

text: In the 1940s two new broadcast media evolved in the US which competed with AM: FM radio and television. By the 1950s, the dominance of AM radio over home entertainment ended. Television replaced AM radio as an evening family pastime; instead of sitting and listening to the radio, families would watch television. By the 1970s FM radio, due to its superior audio quality, attracted serious audiophiles.

text: In the 1940s two new

text: broadcast media

text: evolved in the US which competed with AM:

text: FM radio

text: and

text: television

text: . By the 1950s, the dominance of AM radio over home entertainment ended. Television replaced AM radio as an evening family pastime; instead of sitting and listening to the radio, families would watch television. By the 1970s FM radio, due to its superior audio quality, attracted serious audiophiles.

text: During the application process for the licence, the station's working title was Humber Bridge Radio; however on 17 April 1984, it was launched as Viking Radio and broadcast on 102.7 FM and 1161Khz AM (258m Medium Wave). The first on-air presenter was David Fewster and the first song played was Celebration by Kool & the Gang.  In Spring 1986, the frequency was changed to 96.9 FM, the then residence of arch-competitor Radio Humberside, (which moved to 95.9 FM). In the Summer of 1986, the station hit the showbiz big time by signing up the pop music connoisseur Paul Gambaccini.

text: During the application process for the licence, the station's working title was

text: Humber Bridge

text: Radio; however on 17 April 1984, it was launched as Viking Radio and broadcast on 102.7 FM and 1161Khz AM (258m Medium Wave). The first on-air presenter was David Fewster and the first song played was

text: Celebration

text: by

text: Kool & the Gang

text: .  In Spring 1986, the frequency was changed to 96.9 FM, the then residence of arch-competitor

text: Radio Humberside

text: , (which moved to 95.9 FM). In the Summer of 1986, the station hit the showbiz big time by signing up the

text: pop

text: music

text: connoisseur

text: Paul Gambaccini

text: In telecommunications and electronics, an antenna feed refers to the components of an antenna which feed the radio waves to the rest of the antenna structure, or in receiving antennas collect the incoming radio waves, convert them to electric currents and transmit them to the receiver. Antennas typically consist of a feed and additional reflecting or directive structures (such as a parabolic dish or parasitic elements) whose function is to form the radio waves from the feed into a beam or other desired radiation pattern.

text: In

text: telecommunications

text: and

text: electronics

text: , an antenna feed refers to the components of an

text: antenna

text: which feed the

text: radio wave

text: s to the rest of the antenna structure, or in receiving antennas collect the incoming radio waves, convert them to electric currents and transmit them to the receiver. Antennas typically consist of a feed and additional reflecting or directive structures (such as a

text: parabolic dish

text: or

text: parasitic element

text: s) whose function is to form the radio waves from the feed into a beam or other desired

text: radiation pattern

text: By 2005 Bose introduced the Wave Radio II, which is a Wave Music System without the CD/MP3 player. This system features a dual tapered waveguide and revised drivers. Aside from the lack of a CD player, the Wave Radio II is identical to the Wave Music System.

text: A T-antenna, T-aerial, flat-top antenna, or top-hat antenna is a vertically polarized simple wire radio antenna used in the VLF, LF, MF and shortwave bands.  T-antennas are widely used as transmitting antennas for amateur radio stations, long wave and medium wave broadcasting stations. They are also used as receiving antennas for shortwave listening.

text: A T-antenna, T-aerial, flat-top antenna, or top-hat antenna is a vertically polarized simple wire radio

text: antenna

text: used in the

text: VLF

text: LF

text: MF

text: and

text: shortwave

text: bands.  T-antennas are widely used as transmitting antennas for

text: amateur radio

text: stations,

text: long wave

text: and

text: medium wave

text: broadcasting stations. They are also used as receiving antennas for

text: shortwave listening

text: There are several major radio stations serving the metro area, with a wide variety of musical interests. Contemporary music Station (and arguably the most popular) is WIHT 99.5 FM (Hot 99.5) located in Rockville, Maryland. Rock stations include WTGB 94.7 FM (Triple A) and WWDC 101.1 FM (alternative rock/pop). Urban stations include WPGC 95.5 FM (rhythmic top 40/urban contemporary), WHUR 96.3 FM (Howard University urban adult contemporary station), WMMJ 102.3 FM (urban adult contemporary), WKYS 93.9 FM (urban contemporary), and Radio CPR 97.5 FM (a popular pirate radio station broadcasting in the area around Mount Pleasant, Adams Morgan, and Columbia Heights). Two major contemporary Christian music stations in the region are WGTS 91.9 FM (of Takoma Park) and WPER 89.9 (of Warrenton, Virginia). Stations that concentrate on talk and sports include WJFK 106.7 FM, WMAL 630 AM (conservative), WWRC 1260 AM (progressive talk), WOL 1450 AM, WPGC 1580 AM (gospel), WTEM 980 AM (sports talk), WAVA 105.1 FM (Christian talk radio), WTOP 103.5 FM (news), and WWWT 1500 AM/107.7 FM (3WT/talk). Radio duos Don and Mike and Ron and Fez both had great success on WJFK, although the latter now broadcast on D.C.-based XM Satellite Radio via the network's New York studio.

text: There are several major radio stations serving the metro area, with a wide variety of musical interests.

text: Contemporary music

text: Station (and arguably the most popular) is

text: WIHT

text: 99.5 FM (Hot 99.5) located in

text: Rockville, Maryland

text: Rock

text: stations include

text: WTGB

text: 94.7 FM (

text: Triple A

text: ) and

text: WWDC

text: 101.1 FM (alternative rock/pop).

text: Urban

text: stations include

text: WPGC

text: 95.5 FM (

text: rhythmic top 40

text: /urban contemporary),

text: WHUR

text: 96.3 FM (

text: Howard University

text: urban adult contemporary

text: station),

text: WMMJ

text: 102.3 FM (urban adult contemporary),

text: WKYS

text: 93.9 FM (urban contemporary), and

text: Radio CPR

text: 97.5 FM (a popular

text: pirate radio

text: station broadcasting in the area around

text: Mount Pleasant

text: Adams Morgan

text: , and

text: Columbia Heights

text: ). Two major

text: contemporary Christian music

text: stations in the region are

text: WGTS

text: 91.9 FM (of

text: Takoma Park

text: ) and

text: WPER

text: 89.9 (of

text: Warrenton, Virginia

text: ). Stations that concentrate on talk and sports include

text: WJFK

text: 106.7 FM,

text: WMAL

text: 630 AM (

text: conservative

text: WWRC

text: 1260 AM (

text: progressive talk

text: WOL

text: 1450 AM,

text: WPGC

text: 1580 AM (

text: gospel

text: ), WTEM 980 AM (sports talk),

text: WAVA

text: 105.1 FM (Christian

text: talk radio

text: WTOP

text: 103.5 FM (news), and

text: WWWT

text: 1500 AM/107.7 FM (3WT/talk). Radio duos

text: Don and Mike

text: and

text: Ron and Fez

text: both had great success on WJFK, although the latter now broadcast on D.C.-based

text: XM Satellite Radio

text: via the network's New York studio.

text: J-Wave is a commercial radio station based in Tokyo, Japan, broadcasting on 81.3 FM from the Tokyo Skytree to the Tokyo area. J-Wave airs mostly music covering a wide range of formats. The station is considered the most popular among FM broadcasts in Tokyo, and has surprised the radio broadcast industry by gaining a higher popularity rate than an AM station (JOQR) in a survey conducted in June 2008.  J-Wave was founded in October 1988 with the callsign of JOAV-FM. It is a member station of the Japan FM League (JFL) commercial radio network.

text: J-Wave is a commercial

text: radio station

text: based in

text: Tokyo

text: Japan

text: , broadcasting on 81.3

text: FM

text: from the

text: Tokyo Skytree

text: to the Tokyo area. J-Wave airs mostly music covering a wide range of formats. The station is considered the most popular among FM broadcasts in Tokyo, and has surprised the radio broadcast industry by gaining a higher popularity rate than an AM station (

text: JOQR

text: ) in a survey conducted in June 2008.  J-Wave was founded in October 1988 with the callsign of JOAV-FM. It is a member station of the

text: Japan FM League

text: (JFL) commercial radio network.

text: Hertz's proof of the existence of airborne electromagnetic waves led to an explosion of experimentation with this new form of electromagnetic radiation, which was called "Hertzian waves" until around 1910 when the term "radio waves" became current.  Within 10 years researchers such as Oliver Lodge, Ferdinand Braun, and Guglielmo Marconi employed radio waves in the first wireless telegraphy radio communication systems, leading to radio broadcasting, and later television. Today radio is an essential technology in global telecommunication networks, and the transmission medium underlying modern wireless devices.

text: Hertz's proof of the existence of airborne electromagnetic waves led to an explosion of experimentation with this new form of electromagnetic radiation, which was called "Hertzian waves" until around 1910 when the term "radio waves" became current.  Within 10 years researchers such as

text: Oliver Lodge

text: Ferdinand Braun

text: , and

text: Guglielmo Marconi

text: employed radio waves in the first

text: wireless telegraphy

text: radio communication

text: systems, leading to

text: radio broadcasting

text: , and later television. Today radio is an essential technology in global telecommunication networks, and the transmission medium underlying modern wireless devices.

text: Talk radio is not limited to the AM band. "Non-commercial" usually referred to as "public radio", which is located in a reserved spectrum of the FM band, also broadcasts talk programs. Commercial all-talk stations can also be found on the FM band in many cities across the US. These shows often rely less on political discussion and analysis than their AM counterparts, and often employ the use of pranks and "bits" for entertainment purposes. In the United States and Canada, satellite radio services offer uncensored "free-wheeling" original programming. ABC News & Talk is an example of "repackaging" for the digital airwaves shows featured on their terrestrial radio stations.

text: Talk radio is not limited to the

text: AM band

text: . "Non-commercial" usually referred to as "

text: public radio

text: ", which is located in a reserved spectrum of the

text: FM band

text: , also broadcasts talk programs. Commercial all-talk stations can also be found on the FM band in many cities across the US. These shows often rely less on political discussion and analysis than their AM counterparts, and often employ the use of pranks and "bits" for entertainment purposes. In the

text: United States

text: and

text: Canada

text: satellite radio

text: services offer uncensored "free-wheeling" original programming.

text: ABC News & Talk

text: is an example of "repackaging" for the digital airwaves shows featured on their terrestrial radio stations.

text: Visible light is an electromagnetic wave, consisting of oscillating electric and magnetic fields traveling through space. The frequency of the wave determines its color:  is red light,  is violet light, and between these (in the range 4-) are all the other colors of the visible spectrum. An electromagnetic wave can have a frequency less than , but it will be invisible to the human eye; such waves are called infrared (IR) radiation. At even lower frequency, the wave is called a microwave, and at still lower frequencies it is called a radio wave. Likewise, an electromagnetic wave can have a frequency higher than , but it will be invisible to the human eye; such waves are called ultraviolet (UV) radiation. Even higher-frequency waves are called X-rays, and higher still are gamma rays.

text: Visible light is an

text: electromagnetic wave

text: , consisting of oscillating

text: electric

text: and

text: magnetic field

text: s traveling through space. The frequency of the wave determines its color:  is red light,  is violet light, and between these (in the range 4-) are all the other colors of the

text: visible spectrum

text: . An electromagnetic wave can have a frequency less than , but it will be invisible to the human eye; such waves are called

text: infrared

text: (IR) radiation. At even lower frequency, the wave is called a

text: microwave

text: , and at still lower frequencies it is called a

text: radio wave

text: . Likewise, an electromagnetic wave can have a frequency higher than , but it will be invisible to the human eye; such waves are called

text: ultraviolet

text: (UV) radiation. Even higher-frequency waves are called

text: X-ray

text: s, and higher still are

text: gamma ray

text: s.

text: The first correspondence courses began in the 1800s using parcel post to reach students who couldn't be on a university campus. By the early 1900s, communication technologies improved and distance education took to the radio waves. In 1919 professors at the University of Wisconsin began an amateur radio station, becoming the first licensed radio station dedicated to educational broadcasting. Soon after, access to higher education was again expanded through the invention of the television; giving birth to what was known as the telecourse. The University of Iowa began to experiment with television for educational purposes in the 1930s. It was not until the 1950s, when the FCC began to reserve television frequencies for educational purposes, that telecourses caught the attention of the public. The value of television for education was furthered by the establishment of the Corporation for Public Broadcasting (CPB) in 1967. The CPB mission was "to encourage the growth and development of public radio and television broadcasting, including the use of such media for instructional, educational, and cultural purposes" (as cited in, p. 27).

text: In this figure, a plane wave incident from the left is assumed. The transmittance function in the front focal plane (i.e., Plane 1) spatially modulates the incident plane wave in magnitude and phase, like on the left-hand side of eqn. (2.1) (specified to z=0), and in so doing, produces a spectrum of plane waves corresponding to the FT of the transmittance function, like on the right-hand side of eqn. (2.1) (for z>0). The various plane wave components propagate at different tilt angles with respect to the optic axis of the lens (i.e., the horizontal axis). The finer the features in the transparency, the broader the angular bandwidth of the plane wave spectrum. We'll consider one such plane wave component, propagating at angle θ with respect to the optic axis. It is assumed that θ is small (paraxial approximation), so that

text: In this figure, a plane wave incident from the left is assumed. The transmittance function in the front focal plane (i.e., Plane 1) spatially modulates the incident plane wave in magnitude and phase, like on the left-hand side of eqn. (2.1) (specified to z=0), and in so doing, produces a spectrum of plane waves corresponding to the FT of the transmittance function, like on the right-hand side of eqn. (2.1) (for z>0). The various plane wave components propagate at different tilt angles with respect to the optic axis of the lens (i.e., the horizontal axis). The finer the features in the transparency, the broader the angular bandwidth of the plane wave spectrum. We'll consider one such plane wave component, propagating at angle θ with respect to the optic axis. It is assumed that θ is small (

text: paraxial approximation

text: ), so that

text: Commercial radio stations simulcasted on both FM and medium wave from the beginning until 1989–1990, when the IBA asked radio stations to end the practice. Typically another service, often a Gold format, was introduced on AM and the original service continued on FM.

text: Commercial radio stations

text: simulcast

text: ed on both FM and medium wave from the beginning until 1989–1990, when the

text: IBA

text: asked radio stations to end the practice. Typically another service, often a Gold format, was introduced on AM and the original service continued on FM.

text: A live radio program called Bhoot FM is being aired by Bangladeshi radio channel Radio Foorti 88.0 FM at 12:00 am, every Friday night. The program is being aired since August 13, 2010; and is hosted by RJ Russell. In this program, people from all over Bangladesh come and share their real-life experiences associated with ghosts, demons, jinns and the paranormal/supernatural. The Bengali community from all over the world also share their supernatural experiences by sending audio clips and email that is played/read in this program. Other such radio program is Dor, aired by ABC Radio 89.2 FM. Similar kind of programs are also aired on TV channels, such as Moddhorater Train (meaning 'Midnight Train') by Maasranga Television.

text: A live radio program called Bhoot FM is being aired by Bangladeshi radio channel

text: Radio Foorti

text: 88.0 FM at 12:00 am, every Friday night. The program is being aired since August 13, 2010; and is hosted by RJ Russell. In this program, people from all over

text: Bangladesh

text: come and share their real-life experiences associated with ghosts, demons, jinns and the paranormal/supernatural. The Bengali community from all over the world also share their supernatural experiences by sending audio clips and email that is played/read in this program. Other such radio program is Dor, aired by

text: ABC Radio

text: 89.2 FM. Similar kind of programs are also aired on TV channels, such as Moddhorater Train (meaning 'Midnight Train') by

text: Maasranga Television

text: A skip distance is the distance a radio wave travels, usually including a hop in the ionosphere.  A skip distance is a distance on the Earth's surface between the two points where radio waves from a transmitter, refracted downwards by different layers of the ionosphere, fall. It also represents how far a radio wave has travelled per hop on the Earth's surface, for radio waves such as the short wave (SW) radio signals that employ continuous reflections for transmission.

text: A skip distance is the distance a

text: radio wave

text: travels, usually including a hop in the

text: ionosphere

text: .  A skip distance is a distance on the Earth's surface between the two points where

text: radio waves

text: from a

text: transmitter

text: , refracted downwards by different layers of the

text: ionosphere

text: , fall. It also represents how far a

text: radio wave

text: has travelled per hop on the Earth's surface, for

text: radio waves

text: such as the

text: short wave

text: (SW) radio signals that employ continuous reflections for transmission.

text: The 2003 games were the first to have their opening and closing schemes broadcast on live television, and Radio Telefís Éireann provided extensive coverage of the events through their 'Voice of the Games' radio station which replaced RTÉ Radio 1 on Medium Wave for the duration of the event. There was also a nightly television highlight programme.

text: The 2003 games were the first to have their opening and closing schemes broadcast on live television, and

text: Radio Telefís Éireann

text: provided extensive coverage of the events through their 'Voice of the Games' radio station which replaced

text: RTÉ Radio 1

text: on

text: Medium Wave

text: for the duration of the event. There was also a nightly television highlight programme.

text: This article is about the FM Radio station. For the AM Radio station formerly known as AM 1520 KOMA, see KOKC (AM)

text: This article is about the

text: FM Radio

text: station. For the

text: AM Radio

text: station formerly known as AM 1520 KOMA, see

text: KOKC (AM)

text: In the series, we learn that Geordi was born blind and wears a VISOR, an arc-shaped prosthetic attached at the temples that provides him with vision. Interfacing directly with his brain, the device enables him to "see" much of the electromagnetic spectrum – radio waves, infrared, ultraviolet, and beyond, but not normal light perception, though it does allow Geordi to see the visible light section of the EM spectrum.

text: In the series, we learn that Geordi was born

text: blind

text: and wears a VISOR, an arc-shaped

text: prosthetic

text: attached at the temples that provides him with

text: vision

text: Interfacing

text: directly with his

text: brain

text: , the device enables him to "see" much of the

text: electromagnetic spectrum

text: radio wave

text: s,

text: infrared

text: ultraviolet

text: , and beyond, but not normal

text: light

text: perception, though it does allow Geordi to see the visible light section of the EM spectrum.

text: Portable radios include simple transistor radios that are typically monoaural and receive the AM, FM, or short wave broadcast bands.  FM, and often AM, radios are sometimes included as a feature of portable DVD/CD, MP3 CD, and USB key players, as well as cassette player/recorders.

text: Portable radios include simple

text: transistor radio

text: s that are typically monoaural and receive the AM, FM, or short wave

text: broadcast band

text: s.  FM, and often AM, radios are sometimes included as a feature of portable

text: DVD

text: CD

text: MP3 CD

text: , and

text: USB key player

text: s, as well as

text: cassette player/recorder

text: s.

text: Radio wave sources which are smaller than one radio wavelength are also generally treated as point sources. Radio emissions generated by a fixed electrical circuit are usually polarized, producing anisotropic radiation. If the propagating medium is lossless, however, the radiant power in the radio waves at a given distance will still vary as the inverse square of the distance if the angle remains constant to the source polarization.

text: Radio wave

text: sources which are smaller than one radio

text: wavelength

text: are also generally treated as point sources. Radio emissions generated by a fixed electrical circuit are usually

text: polarized

text: , producing

text: anisotropic

text: radiation. If the propagating medium is lossless, however, the radiant power in the radio waves at a given distance will still vary as the inverse square of the distance if the angle remains constant to the source polarization.

text: A television station is a business, organisation or other enterprise, such as an amateur television (ATV) operator, that transmits (broadcasts) content over terrestrial television. A television transmission can occur via analog television signals or, more recently, via digital television signals. Broadcast television systems standards are set by the government, and these vary around the world. Television stations broadcasting over an analog system were typically limited to one television channel, but digital television enables broadcasting via  subchannels as well. The term "television station" is normally applied to terrestrial television stations, and not to cable television or satellite television broadcasting.

text: A television station is a business, organisation or other enterprise, such as an

text: amateur television

text: (ATV) operator, that transmits (

text: broadcasts

text: ) content over

text: terrestrial television

text: . A television transmission can occur via

text: analog television

text: signals or, more recently, via

text: digital television

text: signals.

text: Broadcast television systems

text: standards are set by the government, and these vary around the world. Television stations broadcasting over an analog system were typically limited to one

text: television channel

text: , but digital television enables broadcasting via

text: subchannel

text: s as well. The term "television station" is normally applied to terrestrial television stations, and not to

text: cable television

text: or

text: satellite television

text: broadcasting.

text: Surface waves have been used in over-the-horizon radar, which operates mainly at frequencies between 2 and 20 MHz over the sea, which has a sufficiently high conductivity to convey the surface waves to and from a reasonable distance (up to 100 km or more; over-horizon radar also uses skywave propagation at much greater distances). In the development of radio, surface waves were used extensively. Early commercial and professional radio services relied exclusively on long wave, low frequencies and ground-wave propagation.  To prevent interference with these services, amateur and experimental transmitters were restricted to the high frequencies (HF), felt to be useless since their ground-wave range was limited.  Upon discovery of the other propagation modes possible at medium wave and short wave frequencies, the advantages of HF for commercial and military purposes became apparent. Amateur experimentation was then confined only to authorized frequencies in the range.

text: Surface waves have been used in

text: over-the-horizon radar

text: , which operates mainly at frequencies between 2 and 20 MHz over the sea, which has a sufficiently high conductivity to convey the surface waves to and from a reasonable distance (up to 100 km or more; over-horizon radar also uses skywave propagation at much greater distances). In the

text: development of radio

text: , surface waves were used extensively. Early commercial and professional radio services relied exclusively on

text: long wave

text: , low frequencies and ground-wave propagation.  To prevent interference with these services, amateur and experimental transmitters were restricted to the high frequencies (HF), felt to be useless since their ground-wave range was limited.  Upon discovery of the other propagation modes possible at

text: medium wave

text: and

text: short wave

text: frequencies, the advantages of HF for commercial and military purposes became apparent. Amateur experimentation was then confined only to authorized frequencies in the range.

text: The Spectrum is an adult album alternative radio station on Sirius XM Radio channel 28 and on Dish Network channel 6028.  Cleverly sandwiched between 1st Wave and Classic Vinyl on the XM dial, the eclectic channel was formerly known as Starbucks XM Cafe from July 2007 to September 2008.

text: The Spectrum is an

text: adult album alternative

text: radio station on

text: Sirius XM Radio

text: channel 28 and on

text: Dish Network

text: channel 6028.  Cleverly sandwiched between

text: 1st Wave

text: and

text: Classic Vinyl

text: on the

text: XM

text: dial, the eclectic channel was formerly known as

text: Starbucks XM Cafe

text: from July 2007 to September 2008.

text: The diagram on the right shows an example of refraction in water waves. Ripples travel from the left and pass over a shallower region inclined at an angle to the wavefront. The waves travel slower in the more shallow water, so the wavelength decreases and the wave bends at the boundary. The dotted line represents the normal to the boundary. The dashed line represents the original direction of the waves. This phenomenon explains why waves on a shoreline tend to strike the shore close to a perpendicular angle. As the waves travel from deep water into shallower water near the shore, they are refracted from their original direction of travel to an angle more normal to the shoreline.Refraction is also responsible for rainbows and for the splitting of white light into a rainbow-spectrum as it passes through a glass prism. Glass has a higher refractive index than air. When a beam of white light passes from air into a material having an index of refraction that varies with frequency, a phenomenon known as dispersion occurs, in which different coloured components of the white light are refracted at different angles, i.e., they bend by different amounts at the interface, so that they become separated. The different colors correspond to different frequencies.

text: The diagram on the right shows an example of refraction in

text: water wave

text: s. Ripples travel from the left and pass over a shallower region inclined at an angle to the wavefront. The waves travel slower in the more shallow water, so the wavelength decreases and the wave bends at the boundary. The dotted line represents the normal to the boundary. The dashed line represents the original direction of the waves. This phenomenon explains why waves on a shoreline tend to strike the shore close to a perpendicular angle. As the waves travel from deep water into shallower water near the shore, they are refracted from their original direction of travel to an angle more normal to the shoreline.Refraction is also responsible for

text: rainbow

text: s and for the splitting of white light into a rainbow-spectrum as it passes through a glass

text: prism

text: . Glass has a higher refractive index than air. When a beam of white light passes from air into a material having an index of refraction that varies with frequency, a phenomenon known as

text: dispersion

text: occurs, in which different coloured components of the white light are refracted at different angles, i.e., they bend by different amounts at the interface, so that they become separated. The different colors correspond to different frequencies.

text: On October 20, 2010, Radio Sweden ceased broadcasts on shortwave and medium wave, as Swedish Radio's management decided that the Internet had matured enough to support international broadcasts. At the same time the English Service was extended to national broadcasts on FM, but programming on weekends was discontinued. Services in English also continue on satellite, both using Swedish Television's satellite and the World Radio Network.

text: On October 20, 2010, Radio Sweden ceased broadcasts on shortwave and medium wave, as Swedish Radio's management decided that the Internet had matured enough to support international broadcasts. At the same time the English Service was extended to national broadcasts on FM, but programming on weekends was discontinued. Services in English also continue on satellite, both using Swedish Television's satellite and the

text: World Radio Network

text: The original television remote control was a wired version, released in 1950, that soon attracted complaints about an unsightly length of cable from the viewer's chair to the television receiver. Cmdr. Eugene F. McDonald, Zenith President and founder, ordered his engineers to develop a wireless version, but the use of radio waves was soon discounted due to poor interference rejection inherent in 1950s radio receivers. The 1955 Flash-Matic remote system, invented by Eugene Polley, used a highly directional photo flash tube in the hand held unit that was aimed at sensitive photoreceivers in the four front corners of the television cabinet. However, bright sunlight falling on the television was found to activate the controls. It is worth noting that these remote controls would activate a motor, causing the tuning dial on the television to switch by itself, and this could be used for mischief if someone else was attempting to tune the television.

text: The original television remote control was a wired version, released in 1950, that soon attracted complaints about an unsightly length of cable from the viewer's chair to the television receiver. Cmdr.

text: Eugene F. McDonald

text: , Zenith President and founder, ordered his engineers to develop a wireless version, but the use of radio waves was soon discounted due to poor interference rejection inherent in 1950s radio receivers. The 1955 Flash-Matic remote system, invented by

text: Eugene Polley

text: , used a highly directional photo flash tube in the hand held unit that was aimed at sensitive photoreceivers in the four front corners of the television cabinet. However, bright sunlight falling on the television was found to activate the controls. It is worth noting that these remote controls would activate a motor, causing the tuning dial on the television to switch by itself, and this could be used for mischief if someone else was attempting to tune the television.

text: The range gated pulsed Doppler microwave radar operates in low grazing angle mode. By using several antennas it may be used as a directional wave sensor, basically measuring the directional spectrum of the horizontal water particle velocity. The velocity spectrum is directly related to the wave height spectrum by a mathematical model based on linear wave theory and accurate measurements of the wave spectrum  can be provided under most conditions. As measurements are taken at a distance from the platform on which it is mounted, the wave field is to a small degree disturbed by interference from the platform structure.

text: A television set, also called a television receiver, television, TV set, TV, or telly, is a device that combines a tuner, display, and speakers for the purpose of viewing television. Introduced in the late 1920s in mechanical form, television sets became a popular consumer product after World War II in electronic form, using cathode ray tubes. The addition of color to broadcast television after 1953 further increased the popularity of television sets in the 1960s, and an outdoor antenna became a common feature of suburban homes. The ubiquitous television set became the display device for the first recorded media in the 1970s, such as VHS and later DVD. In the late 2000s flat panel television incorporating liquid-crystal displays largely replaced cathode ray tubes. Modern flat panel TVs are typically capable of high-definition display (720p, 1080p or 2160p) and can also play content from a USB device.

text: A television set, also called a television receiver, television, TV set, TV, or telly, is a device that combines a tuner, display, and speakers for the purpose of viewing

text: television

text: . Introduced in the late 1920s in

text: mechanical

text: form, television sets became a popular consumer product after World War II in electronic form, using

text: cathode ray tube

text: s. The addition of color to broadcast television after 1953 further increased the popularity of television sets in the 1960s, and an outdoor antenna became a common feature of suburban homes. The ubiquitous television set became the display device for the first recorded media in the 1970s, such as

text: VHS

text: and later

text: DVD

text: . In the late 2000s

text: flat panel

text: television incorporating liquid-crystal displays largely replaced

text: cathode ray tube

text: s. Modern flat panel TVs are typically capable of high-definition display (720p, 1080p or 2160p) and can also play content from a

text: USB

text: device.

text: Digital radio is the use of digital technology to transmit and/or receive across the radio spectrum. The may refer to digital transmission by radio waves, including digital broadcasting, and especially to Digital audio radio services.

text: Digital radio is the use of digital technology to transmit and/or receive across the

text: radio spectrum

text: . The may refer to

text: digital transmission

text: by

text: radio wave

text: s, including

text: digital broadcasting

text: , and especially to

text: Digital audio radio service

text: s.

text: Vatican Radio, which was organised by Guglielmo Marconi, broadcasts on short-wave, medium-wave and FM frequencies and on the Internet. Its main transmission antennae are located in Italian territory, and exceed Italian environmental protection levels of emission. For this reason, the Vatican Radio has been sued. Television services are provided through another entity, the Vatican Television Center.

text: Vatican Radio

text: , which was organised by

text: Guglielmo Marconi

text: , broadcasts on

text: short-wave

text: medium-wave

text: and FM frequencies and on the Internet. Its main transmission antennae are located in Italian territory, and exceed Italian environmental protection levels of emission. For this reason, the Vatican Radio has been

text: sued

text: . Television services are provided through another entity, the

text: Vatican Television Center

text: Baird invented some of the first experimental television systems.  In 1924 he developed a mechanical television system to transmit moving images by means of electrical signals, which he demonstrated on 25 March 1925 at a London department store, Selfridges.   It consisted of a spinning disk set with a spiral pattern of 30 lenses.  As each lens rotated past the illuminated subject, it focused the light from a spot on the subject on a selenium photoelectric cell.  This converted the brightness of the image at each spot into a proportional electric signal, which could be sent to a receiver by radio waves.  As each lens swept past the subject, it scanned a successive line of the image.  At the receiver, a light shining through the holes in a similar rotating disk recreated an image of the subject.

text: Baird invented some of the first experimental

text: television

text: systems.  In 1924 he developed a

text: mechanical television

text: system to transmit moving images by means of electrical signals, which he demonstrated on 25 March 1925 at a London department store, Selfridges.   It consisted of a spinning disk set with a spiral pattern of 30 lenses.  As each lens rotated past the illuminated subject, it focused the light from a spot on the subject on a selenium

text: photoelectric cell

text: .  This converted the brightness of the image at each spot into a proportional electric signal, which could be sent to a receiver by radio waves.  As each lens swept past the subject, it scanned a successive line of the image.  At the receiver, a light shining through the holes in a similar rotating disk recreated an image of the subject.

text: Wave 102 was founded as part of The Petros Radio Group which launched Discovery AM in 1994 and Radio Waves in 1995, then decided to go for the full scale local licence with the help of a consortium which also founded Kingdom FM in Fife with the assistance of IRG (The Independent Radio Group)

text: Wave 102 was founded as part of The Petros Radio Group which launched Discovery AM in 1994 and Radio Waves in 1995, then decided to go for the full scale local licence with the help of a consortium which also founded

text: Kingdom FM

text: in

text: Fife

text: with the assistance of IRG (The Independent Radio Group)

text: ible") in 1950, followed by WGCB-FM in 1958, one of the first FM radio stations in the United States. In 1962, Norris launched short-wave radio station WINB (originally standing for "

text: In radiophysics, the Luxemburg–Gorky effect (named after Radio Luxemburg and Gorky Park) is a phenomenon of cross modulation between two radio waves, one of which is strong, passing through the same part of a medium, especially a conductive region of atmosphere or a plasma.Current theory seems to be that the conductivity of the ionosphere is affected by the presence of strong radio waves. The strength of a radio wave returning from the ionosphere to a distant point is dependent on this conductivity level. Therefore, if station “A” is radiating a strong amplitude modulated radio signal all around, some of it will modulate the conductivity of the ionosphere above the station. Then if station “B” is also sending an amplitude modulated signal from another location, the part of station “B’s” signal that passes through the ionosphere disturbed by station “A” to a receiver in line with both stations may have its strength modulated by the station “A” signal, even though the two are widely apart in frequency.In other words, the ionosphere passes the station “B” signal with a strength that varies in step with the modulation (voice, etc.) of station “A.” This re-modulation level of the station “B” signal is usually only a few percent, but is enough to make both stations audible. The interference (both stations simultaneously received) goes away as the receiver is tuned slightly away from the frequency of “B.”

text: In

text: radiophysics

text: , the Luxemburg–Gorky effect (named after

text: Radio Luxemburg

text: and

text: Gorky Park

text: ) is a

text: phenomenon

text: of

text: cross modulation

text: between two

text: radio waves

text: Most bugs emit some form of electromagnetic radiation, usually radio waves. The standard counter-measure for bugs is therefore to "sweep" for them with a receiver, looking for the radio emissions. Professional sweeping devices are very expensive. Low-tech sweeping devices are available through amateur electrical magazines, or they may be built from circuit designs on the Internet.

text: Most bugs emit some form of

text: electromagnetic radiation

text: , usually

text: radio wave

text: s. The standard counter-measure for bugs is therefore to "sweep" for them with a receiver, looking for the radio emissions. Professional sweeping devices are very expensive. Low-tech sweeping devices are available through amateur electrical

text: magazine

text: s, or they may be built from circuit designs on the

text: Internet

text: The final leg of broadcast distribution is how the signal gets to the listener or viewer. It may come over the air as with a radio station or television station to an antenna and radio receiver, or may come through cable television or cable radio (or "wireless cable") via the station or directly from a network. The Internet may also bring either internet radio or streaming media television to the recipient, especially with multicasting allowing the signal and bandwidth to be shared. The term "broadcast network" is often used to distinguish networks that broadcast an over-the-air television signals that can be received using a tuner (television) inside a television set with a television antenna from so-called networks that are broadcast only via cable television (cablecast) or satellite television that uses a dish antenna. The term "broadcast television" can refer to the television programs of such networks.

text: The final leg of broadcast distribution is how the signal gets to the listener or viewer. It may come over the air as with a

text: radio station

text: or

text: television station

text: to an

text: antenna

text: and

text: radio receiver

text: , or may come through

text: cable television

text: or

text: cable radio

text: (or "

entity_name: Multichannel Multipoint Distribution Service

text: wireless cable

text: ") via the station or directly from a network. The

text: Internet

text: may also bring either

text: internet radio

text: or

text: streaming media

text: television to the recipient, especially with

text: multicast

text: ing allowing the signal and

text: bandwidth

text: to be shared. The term "

text: broadcast network

text: " is often used to distinguish networks that broadcast an over-the-air television signals that can be received using a

text: tuner (television)

text: inside a

text: television set

text: with a

text: television antenna

text: from so-called networks that are broadcast only via

text: cable television

text: cablecast

text: ) or

text: satellite television

text: that uses a

text: dish antenna

text: . The term "

text: broadcast television

text: " can refer to the

text: television program

text: s of such networks.

text: Two kinds of wave modes exit: class 1 waves (sometimes called gravity waves), and class 2 waves (rotational waves). Class 2 waves owe their existence to the Coriolis effect and can only exist for periods larger than 12 hours. Tidal waves can be either internal (travelling waves ) with positive eigenvalues (or equivalent depth)  which have finite vertical wavelengths and can transport wave energy upward, or external (evanescent waves) with negative eigenvalues and infinitely large vertical wavelengths meaning that their phases remain constant with altitude. These external wave modes cannot transport wave energy, and their  amplitudes decrease exponentially with height outside their source regions. Each mode is characterized by four numbers: the zonal wave number n, positive for class 1 waves and negative for class 2 waves (their meridional structures becoming increasingly complex with increasing number n), a meridional wave number m, the eigenvalue, and the period, in our case one solar or lunar day, respectively. The modes are labeled as (m, n). Even numbers of n correspond to waves symmetric with respect to the equator, and odd numbers corresponding to antisymmetric waves.

text: Two kinds of wave modes exit: class 1 waves (sometimes called gravity waves), and class 2 waves (rotational waves). Class 2 waves owe their existence to the

text: Coriolis effect

text: and can only exist for periods larger than 12 hours. Tidal waves can be either internal (travelling waves ) with positive eigenvalues (or equivalent depth)  which have finite vertical wavelengths and can transport wave energy upward, or external (evanescent waves) with negative eigenvalues and infinitely large vertical wavelengths meaning that their phases remain constant with altitude. These external wave modes cannot transport wave energy, and their  amplitudes decrease exponentially with height outside their source regions. Each mode is characterized by four numbers: the zonal wave number n, positive for class 1 waves and negative for class 2 waves (their meridional structures becoming increasingly complex with increasing number n), a meridional wave number m, the eigenvalue, and the period, in our case one solar or

text: lunar day

text: , respectively. The modes are labeled as (m, n). Even numbers of n correspond to waves symmetric with respect to the equator, and odd numbers corresponding to antisymmetric waves.

text: When WNIR became a talk station in the 1970s, it was unusual in that it is an FM talk station, whereas most talk stations were AM.  Now, talk stations on FM are fairly common, many of them aimed at younger audiences. However, WNIR has always operated as more of a traditional, AM-style talk radio station with hourly newscasts and an affiliation with ABC News Radio. WNIR does not broadcast in stereo.

text: When WNIR became a talk station in the 1970s, it was unusual in that it is an

text: FM

text: talk station, whereas most talk stations were

text: AM

text: .  Now, talk stations on FM are fairly common, many of them aimed at younger audiences. However, WNIR has always operated as more of a traditional, AM-style talk radio station with hourly newscasts and an affiliation with

text: ABC News Radio

text: . WNIR does not broadcast in stereo.

text: The early history of radio is the history of technology that produce and use radio instruments that use radio waves.  Within the timeline of radio, many people contributed theory and inventions in what became radio. Radio development began as "wireless telegraphy". Later radio history increasingly involves matters of broadcasting.

text: The early history of radio is the

text: history of technology

text: that produce and use

text: radio instruments

text: that use

text: radio wave

text: s.  Within the

text: timeline of radio

text: , many people contributed theory and inventions in what became

text: radio

text: . Radio development began as "

text: wireless telegraphy

text: ". Later radio history increasingly involves matters of

text: broadcasting

text: In 1864 James Clerk Maxwell showed mathematically that electromagnetic waves could propagate through free space. The effects of electromagnetic waves (then-unexplained "action at a distance" sparking behavior) were actually observed before and after Maxwell's work by many inventors and experimenters including Luigi Galvani (1791), Peter Samuel Munk (1835), Joseph Henry (1842), Samuel Alfred Varley (1852), Edwin Houston, Elihu Thomson, Thomas Edison (1875) and David Edward Hughes (1878). Edison gave the effect the name "etheric force" and Hughes detected a spark impulse up to 500 yards (460 m) with a portable receiver, but none could identify what caused the phenomenon and it was usually written off as electromagnetic induction. In 1886 Heinrich Rudolf Hertz noticed the same sparking phenomenon and, in published experiments (1887-1888), was able to demonstrate the existence of electromagnetic waves in an experiment confirming Maxwell's theory of electromagnetism. The discovery of these "Hertzian waves" (radio waves) prompted many experiments by physicists.  An August 1894 lecture by the British physicist Oliver Lodge, where he transmitted and received "Hertzian waves" at distances up to 50 meters, was followed up a year later with experiments by Indian physicist Jagadish Bose in radio microwave optics and construction of a radio based lightning detector by Russian physicist Alexander Stepanovich Popov. Starting in late 1894, Guglielmo Marconi began pursuing the idea of building a wireless telegraphy system based on Hertzian waves (radio). Marconi gained a patent on the system in 1896 and developed it into a commercial communication system over the next few years.

text: In 1864

text: James Clerk Maxwell

text: showed mathematically that electromagnetic waves could propagate through free space. The effects of electromagnetic waves (then-unexplained "

text: action at a distance

text: " sparking behavior) were actually observed before and after Maxwell's work by many inventors and experimenters including

text: Luigi Galvani

text: (1791), Peter Samuel Munk (1835),

text: Joseph Henry

text: (1842), Samuel Alfred Varley (1852),

text: Edwin Houston

text: Elihu Thomson

text: Thomas Edison

text: (1875) and

text: David Edward Hughes

text: (1878). Edison gave the effect the name "

text: etheric force

text: " and Hughes detected a spark impulse up to 500 yards (460 m) with a portable receiver, but none could identify what caused the phenomenon and it was usually written off as

text: electromagnetic induction

text: . In 1886

text: Heinrich Rudolf Hertz

text: noticed the same sparking phenomenon and, in published experiments (1887-1888), was able to demonstrate the existence of electromagnetic waves in an experiment confirming Maxwell's theory of

text: electromagnetism

text: . The discovery of these "Hertzian waves" (radio waves) prompted many experiments by physicists.  An August 1894 lecture by the British physicist

text: Oliver Lodge

text: , where he transmitted and received "Hertzian waves" at distances up to 50 meters, was followed up a year later with experiments by Indian physicist

text: Jagadish Bose

text: in radio

text: microwave

text: optics

text: and construction of a radio based lightning detector by Russian physicist

text: Alexander Stepanovich Popov

text: . Starting in late 1894,

text: Guglielmo Marconi

text: began pursuing the idea of building a

text: wireless telegraphy

text: system based on Hertzian waves (radio). Marconi gained a patent on the system in 1896 and developed it into a commercial communication system over the next few years.

text: The Figure 1 illustration depicts three important details worth discussing. The first is the Rayleigh line, the peak which has been suppressed at 0 cm-1. This peak is a result of Rayleigh scattering, a form of elastic scattering from the incident photons and the sample. Rayleigh scattering occurs when the induced polarization of the atoms, resulting from the incident photons, does not couple with possible vibrational modes of the atoms. The resulting emitted radiation has the same energy as the incident radiation, meaning no wavenumber shift is observed. This peak is generally quite intense and is not of direct interest for Brillouin spectroscopy. In an experiment the incident light is most often a high power laser. This results in a very intense Rayleigh peak which has the ability to wash out the Brillouin peaks of interest. In order to adjust for this, most spectrum are plotted with the Rayleigh peak either filtered out or suppressed. The second noteworthy aspect of Figure 1 is the distinction between Brillouin and Raman peaks. As previously mentioned, Brillouin peaks range from 0.1 cm-1 to approximately 6 cm-1 while Raman scattering wavenumbers ranges from 10–10000 cm¬-1 (Polian, 2003). As Brillouin and Raman spectroscopy probe two fundamentally different interaction regimes this is not too large of an inconvenience. The fact that Brillouin interactions are such low frequency however creates technical challenges when performing experiments for which a Fabry-Perot interferometer must be used in order to overcome. A Raman spectroscopy system is generally less technically complicated and can be performed with a diffraction grating spectrometer.Figure 1 also highlights the difference between Stokes and anti-Stokes scattering. Stokes scattering, positive photon creation, is displayed as a positive shift in wavenumber. Anti-Stokes scattering, negative photon annihilation, is displayed as a negative shift in wavenumber. The locations of peaks are symmetric about the Rayleigh line because they correspond to the same energy level transition but of a different sign (Muller et al., 2005). In practice six Brillouin lines, of interest, are generally seen in a Brillouin spectrum. Acoustic waves have three polarization directions one longitudinal and two transverse directions each being orthogonal to the others, Figure 2. Solids can be considered nearly incompressible, within an appropriate pressure regime, as a result longitudinal waves, which are transmitted via compression parallel to the propagation direction, can transmit their energy through the material easily and thus travel quickly. The motion of transverse waves, on the other hand, is perpendicular to the propagation direction and is thus less easily propagated through the medium. As a result, longitudinal waves travel more quickly through solids than transverse waves. An example of this can be seen in quartz with an approximate acoustic longitudinal wave velocity of 5965 m/s and transverse wave velocity of 3750 m/s. Interestingly, fluids cannot support transverse waves. As a result, transverse wave signals are not found in Brillouin spectra of fluids. Equation 3 shows the relationship between acoustic wave velocity, V, and phonon wavenumber, Ω (Polian, 2003).

text: In telecommunications, a carrier wave, carrier signal, or just carrier, is a waveform (usually sinusoidal) that is modulated (modified) with an  input signal for the purpose of conveying information. This carrier wave is usually a much higher frequency than the input signal.  The purpose of the carrier is usually either to transmit the information through space as an electromagnetic wave (as in radio communication), or to allow several carriers at different frequencies to share a common physical transmission medium by frequency division multiplexing (as, for example, a cable television system). The term is also used for an unmodulated emission in the absence of any modulating signal.

text: In

text: telecommunications

text: , a carrier wave, carrier signal, or just carrier, is a

text: waveform

text: (usually

text: sinusoidal

text: ) that is

text: modulated

text: (modified) with an

text: input signal

text: for the purpose of conveying information. This carrier wave is usually a much higher

text: frequency

text: than the input signal.  The purpose of the carrier is usually either to transmit the information through space as an

text: electromagnetic wave

text: (as in radio communication), or to allow several carriers at different frequencies to share a common physical transmission medium by

text: frequency division multiplexing

text: (as, for example, a

text: cable television

text: system). The term is also used for an unmodulated

text: emission

text: in the absence of any modulating signal.

text: Normally radio "ground waves" propagate along the surface as creeping waves.  That is, they are only diffracted around the curvature of the earth.  This is one reason that early long distance radio communication used long wavelengths.  The best known exception is that HF (3–30 MHz.) waves are reflected by the ionosphere.

text: Normally radio "

text: ground wave

text: s" propagate along the surface as

text: creeping wave

text: s.  That is, they are only

text: diffracted

text: around the curvature of the earth.  This is one reason that early long distance radio communication used long wavelengths.  The best known exception is that HF (3–30 MHz.) waves are reflected by the

text: ionosphere

text: XEPP-AM/XHPP-FM is an AM/FM combo radio station in Cuapichapan, Fortín and Orizaba, Veracruz.

text: XEPP-AM/XHPP-FM is an AM/FM combo radio station in

text: Cuapichapan

text: Fortín

text: and

text: Orizaba

text: , Veracruz.

text: Porter made many television and radio appearances. He was an original presenter of BBC Radio 3's Night Waves, a programme on which he was scheduled to appear, discussing doctors in literature, at the point of his death.

text: Porter made many television and radio appearances. He was an original presenter of

text: BBC Radio 3

text: 's

text: Night Waves

text: , a programme on which he was scheduled to appear, discussing doctors in literature, at the point of his death.

text: Chuck Dunaway is a retired radio personality and owner known for his work with a number of popular radio stations in Texas, Ohio, Oklahoma and New York City. Dunaway occupied the afternoon drive slot at every radio station he worked at during his 35-year career, including radio  KILT-AM Houston, KLIF-AM Dallas, WKY Oklahoma City, WABC (AM) New York City and WIXY Cleveland. He finished his career as the owner and operator of six FM and two AM radio stations in Joplin, Missouri.

text: Chuck Dunaway is a retired radio personality and owner known for his work with a number of popular radio stations in

text: Texas

text: Ohio

text: Oklahoma

text: and

text: New York City

text: . Dunaway occupied the afternoon drive slot at every radio station he worked at during his 35-year career, including radio

text: KILT-AM

text: Houston

text: KLIF-AM

text: Dallas

text: WKY

text: Oklahoma City

text: WABC (AM)

text: New York City

text: and

text: WIXY

text: Cleveland

text: . He finished his career as the owner and operator of six

text: FM

text: and two

text: AM

text: radio stations in

text: Joplin, Missouri

text: The radio signal from a spark gap transmitter consisted of pulses of radio waves (damped waves) which repeated at an audio rate, around several hundred per second.  Each pulse of radio waves produced a pulse of current in the earphone, so the signal sounded like a musical tone or buzz in the earphone.

text: The radio signal from a spark gap transmitter consisted of pulses of radio waves (

text: damped wave

text: s) which repeated at an audio rate, around several hundred per second.  Each pulse of radio waves produced a pulse of current in the earphone, so the signal sounded like a musical tone or buzz in the earphone.

text: The song was covered by Valli for a 1992 French compilation named  1992 - Les Plus Belles Chansons françaises. In 2003, Biba Binoche, a young woman who had participated in the European reality show Big Brother, and most known under the pseudonym BB, covered the song in various techno and electro version. She released "Je t'aime mélancolie" as single in Belgium and the latter had managed to appear on the Ultratop 40 Singles Chart for seven weeks in 2003, peaking at number 35. The song was available in three formats: CD single (electro radio edit, groove radio edit, trance radio edit), CD maxi (6 versions: electro radio remix, trance radio edit, electro extended mix, trance extended remix, Frank Trauner electro wave, funked lounge version, groove XL remix), and 12" maxi (5 versions: electro extended mix, Frank Trauner electro wave, funked lounge version, groove XL remix, trance extended version).

text: The song was covered by Valli for a 1992

text: French

text: compilation

text: named  1992 - Les Plus Belles Chansons françaises. In 2003, Biba Binoche, a young woman who had participated in the

text: Europe

text: an

text: reality show

text: Big Brother

text: , and most known under the pseudonym BB, covered the song in various

text: techno

text: and

text: electro

text: version. She released "Je t'aime mélancolie" as single in Belgium and the latter had managed to appear on the

text: Ultratop 40 Singles Chart

text: for seven weeks in 2003, peaking at number 35. The song was available in three formats:

text: CD single

text: (electro radio edit, groove radio edit, trance radio edit),

text: CD maxi

text: (6 versions: electro radio remix, trance radio edit, electro extended mix, trance extended remix, Frank Trauner electro wave, funked lounge version, groove XL remix), and

text: 12" maxi

text: (5 versions: electro extended mix, Frank Trauner electro wave, funked lounge version, groove XL remix, trance extended version).

text: Radio stations in Austin include KAUS (AM) (1480 AM,  local news/talk), KAUS-FM (99.9 FM, country), KNSE (90.1 FM, public talk radio), KLSE (FM) (103.3 FM, public classical radio), KNSE (103.9 FM, public AAA), KQAQ (970 AM, classic country).

text: Radio stations in Austin include

text: KAUS (AM)

text: (1480 AM,  local news/talk),

text: KAUS-FM

text: (99.9 FM, country),

text: KNSE

text: (90.1 FM, public talk radio),

text: KLSE (FM)

text: (103.3 FM, public classical radio),

text: KNSE

text: (103.9 FM, public AAA),

text: KQAQ

text: (970 AM, classic country).

text: To form an image of the antenna above it, the ground plane need not be grounded to the Earth.  Many antenna types, such as reflective array antennas, use flat surfaces of metal or metal screen to reflect radio waves from the antenna elements, and these can be analyzed using image antennas.  If there is more than one reflective surface in the antenna, as in a corner reflector antenna, each surface forms its own image of the antenna elements.    In order to form an image, the ground plane surface must generally have dimensions of at least a quarter-wavelength of the radio waves used.

text: To form an image of the antenna above it, the

text: ground plane

text: need not be grounded to the Earth.  Many antenna types, such as

text: reflective array antenna

text: s, use flat surfaces of metal or metal screen to reflect radio waves from the antenna elements, and these can be analyzed using image antennas.  If there is more than one reflective surface in the antenna, as in a

text: corner reflector

text: antenna, each surface forms its own image of the antenna elements.    In order to form an image, the ground plane surface must generally have dimensions of at least a quarter-

text: wavelength

text: of the radio waves used.

text: "Radio Waves" introduces the main character, Billy, a disabled man who finds a way to talk and become friends with a radio DJ. Billy is gifted and has the miracle of hearing and interpreting  radio waves in his head. He explores a cordless phone which was hidden in his wheelchair by his brother Benny, after destroying and robbing a store. Recognising its similarity to a radio, he experiments with the phone and is able to access computers and speech synthesizers, he learns to speak through them. He calls a radio station in L.A. named Radio KAOS, a completely fictitious radio station based in Los Angeles and tells them of his abilities and his life story throughout the album.

text: Electromagnetic waves are a type of wave that originate from charged particles, are characterized by varying wavelength and are categorized along the electromagnetic spectrum. Any device that uses electricity will emit electromagnetic radiation due to the magnetic field created by charged particles moving along a medium. For example, radio waves are emitted by electricity moving along a radio transmitter, or even from a satellite.

text: Electromagnetic wave

text: s are a type of wave that originate from

text: charged particles

text: , are characterized by varying

text: wavelength

text: and are categorized along the

text: electromagnetic spectrum

text: . Any device that uses electricity will emit electromagnetic radiation due to the

text: magnetic field

text: created by charged particles moving along a

text: medium

text: . For example,

text: radio wave

text: s are emitted by

text: electricity

text: moving along a

text: radio transmitter

text: , or even from a

text: satellite

text: Galaxy South Coast, as Power FM, went digital in 2003, airing on DAB digital radio in Southern Hampshire, along with sister stations Ocean FM, XFM and Gold (formerly Capital Gold), as well as Wave 105, Radio Hampshire (formerly The Saint), Traffic Radio (formerly broadcasting as Channel 9, which included Capital Disney, Southampton Hospital Radio and South City FM) and BBC Radio Solent.

text: Galaxy South Coast, as Power FM, went digital in 2003, airing on

text: DAB

text: digital radio in Southern Hampshire, along with sister stations Ocean FM,

text: XFM

text: and

text: Gold

text: (formerly

text: Capital Gold

text: ), as well as

text: Wave 105

entity_name: The Breeze (East Hampshire & South West Surrey)

text: Radio Hampshire

text: (formerly

text: The Saint

text: Traffic Radio

text: (formerly broadcasting as Channel 9, which included

text: Capital Disney

text: , Southampton Hospital Radio and South City FM) and

text: BBC Radio Solent

text: A television licence is required for each household where television programmes are watched or recorded as they are broadcast, irrespective of the signal method (terrestrial, satellite, cable or the Internet). A licence is not required if a television is only used to watch DVDs or play video games.

text: Local radio is provided by Radio Wave, a commercial radio station based on Mowbray Drive in Blackpool which covers the Fylde Coast area. The radio station broadcasts on 96.5FM and is owned by media company UTV. Blackpool also falls in the coverage area of BBC Radio Lancashire, Rock FM, Magic 999, Smooth FM 100.4 and 105.4 Real Radio.

text: Local radio is provided by

text: Radio Wave

text: , a commercial radio station based on Mowbray Drive in Blackpool which covers the Fylde Coast area. The radio station broadcasts on 96.5FM and is owned by media company

text: UTV

text: . Blackpool also falls in the coverage area of

text: BBC Radio Lancashire

text: Rock FM

text: Magic 999

text: Smooth FM 100.4

text: and

text: 105.4 Real Radio

text: A Medium wave radio station is operated by All India Radio, with most programs in Tamil, English and Hindi. Five FM radio stations operate from Coimbatore – Rainbow FM from All India Radio, Suryan FM from Sun Network, Radio Mirchi, Radio City, and Hello FM. All these private radio stations air exclusively Tamil based programs, including film music. Television relay started in 1985 from Delhi Doordarshan. In 1986, after inception of a repeater tower at Kodaikanal, telecast from Madras Doordarshan commenced. Currently television reception is through DTH or by cable, while Doordarshan reception is still available using an external antenna. In 2005, Doordarshan opened its studio in Coimbatore.

text: A Medium wave radio station is operated by

text: All India Radio

text: , with most programs in Tamil, English and Hindi. Five

text: FM radio

text: stations operate from Coimbatore – Rainbow FM from

text: All India Radio

text: Suryan FM

text: from

text: Sun Network

text: Radio Mirchi

text: Radio City

text: , and

text: Hello FM

text: . All these private radio stations air exclusively

text: Tamil

text: based programs, including film music. Television relay started in 1985 from Delhi

text: Doordarshan

text: . In 1986, after inception of a repeater tower at

text: Kodaikanal

text: , telecast from Madras Doordarshan commenced. Currently television reception is through

text: DTH

text: or by cable, while Doordarshan reception is still available using an external antenna. In 2005, Doordarshan opened its studio in Coimbatore.

text: TV's broad reach makes it a powerful and attractive medium for advertisers. Many TV networks and stations sell blocks of broadcast time to advertisers ("sponsors") to fund their programming. Television advertisements (variously called a television commercial, commercial or ad in American English, and known in British English as an advert) is a span of television programming produced and paid for by an organization, which conveys a message, typically to market a product or service. Advertising revenue provides a significant portion of the funding for most privately owned television networks. The vast majority of television advertisements today consist of brief advertising spots, ranging in length from a few seconds to several minutes (as well as program-length infomercials). Advertisements of this sort have been used to promote a wide variety of goods, services and ideas since the beginning of television.

text: TV's broad reach makes it a powerful and attractive medium for advertisers. Many TV networks and stations sell blocks of broadcast time to advertisers ("sponsors") to fund their programming. Television advertisements (variously called a television commercial, commercial or ad in

text: American English

text: , and known in

text: British English

text: as an advert) is a span of

text: television program

text: ming produced and paid for by an organization, which conveys a message, typically to market a product or service. Advertising revenue provides a significant portion of the funding for most privately owned

text: television networks

text: . The vast majority of television advertisements today consist of brief advertising spots, ranging in length from a few seconds to several minutes (as well as program-length

text: infomercial

text: s). Advertisements of this sort have been used to promote a wide variety of goods, services and ideas since the beginning of television.

text: While FM radio can also be received by cable, AM radio generally is not available, although AM stations are sometimes converted into FM cable signals. In Canada, cable operators that offer FM cable services are required by the CRTC to distribute all locally available AM stations in this manner. In Switzerland a system known as "wire broadcasting" (Telefonrundspruch in German) transmitted AM signals over telephone lines in the longwave band until 1998, when it was shut down.  In the UK, Rediffusion was an early pioneer of AM radio cable distribution.

text: While FM radio can also be received by

text: cable

text: , AM radio generally is not available, although AM stations are sometimes converted into FM cable signals. In Canada, cable operators that offer FM cable services are required by the

entity_name: Canadian Radio-television and Telecommunications Commission

text: CRTC

text: to distribute all locally available AM stations in this manner. In Switzerland a system known as "wire broadcasting" (Telefonrundspruch in German) transmitted AM signals over telephone lines in the

text: longwave

text: band until 1998, when it was shut down.  In the UK,

text: Rediffusion

text: was an early pioneer of AM radio cable distribution.

text: During the early-mid 90s its format alternated between sports and a simulcast of sister Top-40 station WNNO-FM (106.9), or was otherwise off the air, usually after sunset. WNNO and WNNO-FM had studios together on Superior Street in Wisconsin Dells and would usually be on the air from 6AM-12 midnight. In the late 1990s WNNO-AM and WNNO-FM were purchased by Magnum Radio Group and studios were moved to Church Street, Wisconsin Dells, using the call of WBKY-FM (95.9) Portage. By this time, WNNO-AM had become nothing but a simulcast of WIBU-AM (1240) Poynette/Portage, which aired Jones Radio Networks' Classic Hit Country format at the time. The calls were subsequently changed to WDLS; concurrently, WNNO-FM became Jones Hot AC under the name "Mix 106"

text: During the early-mid 90s its format alternated between sports and a simulcast of sister Top-40 station

text: WNNO

text: -FM (106.9), or was otherwise off the air, usually after sunset. WNNO and WNNO-FM had studios together on Superior Street in Wisconsin Dells and would usually be on the air from 6AM-12 midnight. In the late 1990s WNNO-AM and WNNO-FM were purchased by

text: Magnum Radio Group

text: and studios were moved to Church Street, Wisconsin Dells, using the call of WBKY-FM (95.9) Portage. By this time, WNNO-AM had become nothing but a simulcast of WIBU-AM (1240) Poynette/Portage, which aired

text: Jones Radio Networks'

text: Classic Hit Country format at the time. The calls were subsequently changed to WDLS; concurrently, WNNO-FM became Jones Hot AC under the name "Mix 106"

text: CFRC remained a CBC station for several years however, with a weak signal and with commercial limitations placed on it by the university (such as a ban on advertising for patent medicine), the Whig-Standard sought its own station and, in 1942, launched CKWS AM 960 (now an FM station), at which time CKWS acquired CFRC's CBC affiliation and its commercial license. In exchange for CKWS carrying some programming from the university, CFRC agreed not to compete commercially with CKWS for ten years and to only engage in broadcasts that filled the university's educational mandate. The station reverted to an experimental outlet for the university's Electrical Engineering Department until 1945 when it resumed programming on a limited basis as part of the Summer Radio Institute - a training program for broadcasters run with the CBC - and thereafter broadcasting non-commercial radio plays by the Queen's Drama Guild. Since the station originally began broadcasting, CFRC periodically changed frequencies until it settled on 1490 AM on March 29, 1941. In 1954, CFRC-FM began broadcasting at 91.9 Megacycles on the FM dial to simulcast the programming of CFRC/1490. In 1957, the university appointed Margaret Angus as its first Director of Radio and students formed the CFRC Radio Club to produce programming and operate the station under her supervision as a fully fledged campus radio station. In 1986, the Canadian Radio-television and Telecommunications Commission approved Radio Queen's application to change CFRC-FM's frequency from 91.9 MHz to its current FM frequency, 101.9 MHz. In 1990 the AM frequency went dark and all CFRC programming moved to the FM frequency (which had been broadcasting separate programming since 1970) and a new stereo transmitter.

text: CFRC remained a CBC station for several years however, with a weak signal and with commercial limitations placed on it by the university (such as a ban on advertising for

text: patent medicine

text: ), the Whig-Standard sought its own station and, in 1942, launched CKWS AM 960 (now

text: an FM station

text: ), at which time CKWS acquired CFRC's CBC affiliation and its commercial license. In exchange for CKWS carrying some programming from the university, CFRC agreed not to compete commercially with CKWS for ten years and to only engage in broadcasts that filled the university's educational mandate. The station reverted to an experimental outlet for the university's Electrical Engineering Department until 1945 when it resumed programming on a limited basis as part of the Summer Radio Institute - a training program for broadcasters run with the CBC - and thereafter broadcasting non-commercial radio plays by the Queen's Drama Guild. Since the station originally began broadcasting, CFRC periodically changed frequencies until it settled on 1490 AM on March 29, 1941. In 1954, CFRC-FM began broadcasting at 91.9 Megacycles on the FM dial to simulcast the programming of CFRC/1490. In 1957, the university appointed Margaret Angus as its first Director of Radio and students formed the CFRC Radio Club to produce programming and operate the station under her supervision as a fully fledged

text: campus radio

text: station. In 1986, the

text: Canadian Radio-television and Telecommunications Commission

text: approved Radio Queen's application to change CFRC-FM's frequency from 91.9 MHz to its current FM frequency, 101.9 MHz. In 1990 the AM frequency went dark and all CFRC programming moved to the FM frequency (which had been broadcasting separate programming since 1970) and a new stereo transmitter.

text: In 1862-4 James Clerk Maxwell developed equations for the electromagnetic field which suggested that waves in the field would travel with a speed that was very close to the known speed of light. Maxwell therefore suggested that visible light (as well as invisible infrared and ultraviolet rays by inference) all consisted of propagating disturbances (or radiation) in the electromagnetic field. Radio waves were first produced deliberately by Heinrich Hertz in 1887, using electrical circuits calculated to produce oscillations at a much lower frequency than that of visible light, following recipes for producing oscillating charges and currents suggested by Maxwell's equations. Hertz also developed ways to detect these waves, and produced and characterized what were later termed radio waves and microwaves.

text: In 1862-4

text: James Clerk Maxwell

text: developed equations for the electromagnetic field which suggested that waves in the field would travel with a speed that was very close to the known speed of light. Maxwell therefore suggested that visible light (as well as invisible infrared and ultraviolet rays by inference) all consisted of propagating disturbances (or radiation) in the electromagnetic field. Radio waves were first produced deliberately by

text: Heinrich Hertz

text: in 1887, using electrical circuits calculated to produce oscillations at a much lower frequency than that of visible light, following recipes for producing oscillating charges and currents suggested by Maxwell's equations. Hertz also developed ways to detect these waves, and produced and characterized what were later termed

text: radio wave

text: s and

text: microwave

text: s.

text: Another type of loading coil is used in radio antennas.  Monopole and dipole radio antennas are designed to act as resonators for radio waves; the power from the transmitter, applied to the antenna through the antenna's transmission line, excites standing waves  of voltage and current in the antenna element.  To be resonant, the antenna must have a physical length of one quarter of the wavelength of the radio waves used (or a multiple of that length).   At resonance the antenna acts electrically as a pure resistance, absorbing all the power applied to it from the transmitter.

text: Another type of loading coil is used in radio

text: antenna

text: s.

text: Monopole

text: and

text: dipole

text: radio antennas are designed to act as

text: resonator

text: s for radio waves; the power from the transmitter, applied to the antenna through the antenna's

text: transmission line

text: , excites

text: standing wave

text: s  of voltage and current in the antenna element.  To be resonant, the antenna must have a physical length of one quarter of the

text: wavelength

text: of the radio waves used (or a multiple of that length).   At resonance the antenna acts electrically as a pure

text: resistance

text: , absorbing all the power applied to it from the transmitter.

text: It also has one FM radio station, WEFM, and one AM radio station, WIMS AM 1420.

text: It also has one

text: FM radio

text: station,

text: WEFM

text: , and one

text: AM radio

text: station,

text: WIMS

text: AM 1420.

text: Video modulation is a strategy of transmitting video signal in the field of radio modulation and television technology. This strategy enables the video signal to be transmitted more efficiently through long distances. In general, video modulation means that a higher frequency carrier wave is modified according to the original video signal. In this way, carrier wave contains the information in the video signal. Then, the carrier will "carry" the information in the form of radio frequency (RF) signal. When carrier reaches its destination, the video signal is extracted from the carrier by decoding. In other words, the video signal is first combined with a higher frequency carrier wave so that carrier wave contains the information in video signal. The combined signal is called radio-frequency signal. At the end of this transmitting system, the RF signals stream from a light sensor and hence, the receivers can obtain the initial data in the original video signal.

text: Video modulation is a strategy of transmitting video signal in the field of radio

text: modulation

text: and

text: television technology

text: . This strategy enables the video signal to be transmitted more efficiently through long distances. In general, video modulation means that a higher frequency carrier wave is modified according to the original video signal. In this way, carrier wave contains the information in the video signal. Then, the carrier will "carry" the information in the form of

text: radio frequency

text: (RF) signal. When carrier reaches its destination, the video signal is extracted from the carrier by decoding. In other words, the video signal is first combined with a higher frequency carrier wave so that carrier wave contains the information in video signal. The combined signal is called radio-frequency signal. At the end of this

text: transmitting system

text: , the RF signals stream from a light

text: sensor

text: and hence, the receivers can obtain the initial data in the original video signal.

text: 1010 KLAT signed on as KODA July 31, 1961 by Paul Taft of the Taft Broadcasting Company  (no relation to Taft Broadcasting of Cincinnati, Ohio) in order to reach a mainstream audience who, at the time, mostly had AM-only radios. KODA had already operated on FM radio at 99.1 megahertz since 1958 when the former KPRC-FM, then KODA-FM (now KODA), was acquired. Both stations broadcast a simulcast beautiful music format (competing with KXYZ) and brought back ABC Radio network programs to Houston. Several years before, KXYZ dropped the ABC Radio affiliation, which resulted in the network only being aired on the eastern rimshot 1360 KWBA (now KWWJ) Baytown, Texas until KODA's sign-on. KODA was a daytimer in the beginning of its existence, meaning Taft could operate the medium wave station only in the daytime (presently licensed as "Class D") while the FM simulcasted the AM station during the day and continued the programming during the overnight hours when the AM station had to shutoff at sunset. In 1978, Group W Westinghouse Broadcasting purchased the stations from Taft and quickly re-sold the AM station. The KODA calls were then changed to KLAT in 1979, along with  the format flipping to popular Spanish language music, branded as "La Tremenda". The station eventually obtained authorization for 24-hour operation ("Class B" status) in 1984.

text: 1010 KLAT signed on as KODA July 31, 1961 by Paul Taft of the Taft Broadcasting Company  (no relation to

text: Taft Broadcasting

text: of

text: Cincinnati, Ohio

text: ) in order to reach a mainstream audience who, at the time, mostly had AM-only radios. KODA had already operated on

text: FM

text: radio at 99.1

text: megahertz

text: since 1958 when the former

text: KPRC-FM

text: , then KODA-FM (now KODA), was acquired. Both stations broadcast a simulcast

text: beautiful music

text: format (competing with

text: KXYZ

text: ) and brought back

text: ABC Radio

text: network programs to Houston. Several years before,

text: KXYZ

text: dropped the ABC Radio affiliation, which resulted in the network only being aired on the eastern rimshot 1360 KWBA (now

text: KWWJ

text: Baytown, Texas

text: until KODA's sign-on. KODA was a daytimer in the beginning of its existence, meaning Taft could operate the

text: medium wave

text: station only in the daytime (presently licensed as "Class D") while the FM simulcasted the AM station during the day and continued the programming during the overnight hours when the AM station had to shutoff at sunset. In 1978, Group W

text: Westinghouse Broadcasting

text: purchased the stations from Taft and quickly re-sold the AM station. The KODA calls were then changed to KLAT in 1979, along with  the format flipping to popular Spanish language music, branded as "La Tremenda". The station eventually obtained authorization for 24-hour operation ("Class B" status) in 1984.

text: In shortwave radio communication, a major mode of long distance propagation  is for the radio waves to reflect off the ionized layers of the atmosphere and return diagonally back to Earth.  In this way radio waves can travel beyond the horizon, around the curve of the Earth.  However the refractive index of the ionosphere decreases with increasing frequency, so there is an upper limit to the frequency which can be used.   Above this frequency the radio waves are not reflected by the ionosphere but are transmitted through it into space.

text: In

text: shortwave

text: radio communication, a major mode of long distance propagation  is for the

text: radio wave

text: s to reflect off the

text: ionized

text: layers of the atmosphere and return diagonally back to Earth.  In this way radio waves can travel beyond the horizon, around the curve of the Earth.  However the

text: refractive index

text: of the ionosphere decreases with increasing frequency, so there is an upper limit to the frequency which can be used.   Above this frequency the radio waves are not reflected by the ionosphere but are transmitted through it into space.

text: Polarization (also polarisation) is a parameter applying to waves that specifies the geometrical orientation of the oscillation. Electromagnetic waves such as light exhibit multiple polarizations, as do many other types of waves such as gravitational waves and sound waves in solids. On the other hand, sound waves in a gas or liquid only oscillate in the wave's direction of propagation, and the oscillation of ocean waves is always in the vertical direction. In these cases one doesn't normally speak of "polarization" since the oscillation's direction is not in question.

text: Polarization (

entity_name: American and British English spelling differences

text: also

text: polarisation) is a parameter applying to

text: wave

text: s that specifies the geometrical orientation of the

text: oscillation

text: Electromagnetic wave

text: s such as

text: light

text: exhibit multiple polarizations, as do many other types of waves such as

text: gravitational wave

text: s and sound waves in solids. On the other hand,

text: sound wave

text: s in a gas or liquid only

text: oscillate in the wave's direction of propagation

text: , and the oscillation of

text: ocean waves

text: is always in the vertical direction. In these cases one doesn't normally speak of "polarization" since the oscillation's direction is not in question.

text: Antennas transmit or receive radio waves

text: Antenna

text: s transmit or receive radio waves

text: Jordan had six AM, five FM, and one short-wave radio broadcast stations as of 1999, as well as a reported 20 television broadcast stations in 1995. A new radio and satellite station were scheduled to begin operations in June 2006 after two earlier delays. Jordanians had more than 1.6 million radio receivers in 1997 and 560,000 television receivers by 2000. Additionally, the country has six daily newspapers and 14 weeklies, as well as 270 other periodicals (with an average circulation of 148,000 in 1998).

text: Jordan had six

text: AM

text: , five

text: FM

text: , and one

text: short-wave

text: radio broadcast stations as of 1999, as well as a reported 20 television broadcast stations in 1995. A new radio and

text: satellite

text: station were scheduled to begin operations in June 2006 after two earlier delays. Jordanians had more than 1.6 million radio receivers in 1997 and 560,000 television receivers by 2000. Additionally, the country has six daily newspapers and 14 weeklies, as well as 270 other periodicals (with an average circulation of 148,000 in 1998).

text: Conducting short-wave radio transmissions between ground-based amateur radio operators and a Shuttle-basedamateur radio operator was the basis for the Shuttle Amateur Radio Experiment (SAREX)-II.SAREX communicated with amateur stations in line-of-sight of the orbiter in one of four transmission modes: voice,slow scan television (SSTV), data or (uplink only) fast scan television (FSTV).The voice mode was operated in the attended mode while SSTV, data or FSTV could be operated in either attended orunattended modes. During the mission, SAREX was operated by Payload Specialist Ron Parise, a licensed operator (WA4SIR),during periods when he was not scheduled for orbiter or other payload activities. A ground-based experiment to calibrate electro-optical sensors at Air Force Maui Optical Site (AMOS) in Hawaii was also conducted during the mission. The Space Classroom Program: Assignment: The Stars project was carried out to spark student interest in science, mathematics and technology. Mission Specialist Hoffman conducted the first classroom lesson taught from space on 7 December in support of this objective, covering material on the electromagnetic spectrum and the ASTRO-1 observatory. A supporting lesson was taught from the ASTRO-1 control center in Huntsville.

text: Conducting short-wave radio transmissions between ground-based amateur radio operators and a Shuttle-basedamateur radio operator was the basis for the Shuttle Amateur Radio Experiment (SAREX)-II.SAREX communicated with amateur stations in line-of-sight of the orbiter in one of four transmission modes: voice,slow scan television (SSTV), data or (uplink only) fast scan television (FSTV).The voice mode was operated in the attended mode while SSTV, data or FSTV could be operated in either attended orunattended modes. During the mission, SAREX was operated by Payload Specialist Ron Parise, a licensed operator (WA4SIR),during periods when he was not scheduled for orbiter or other payload activities. A ground-based experiment to calibrate electro-optical sensors at Air Force

text: Maui

text: Optical Site (AMOS) in Hawaii was also conducted during the mission. The Space Classroom Program: Assignment: The Stars project was carried out to spark student interest in science, mathematics and technology. Mission Specialist Hoffman conducted the first classroom lesson taught from space on 7 December in support of this objective, covering material on the electromagnetic spectrum and the ASTRO-1 observatory. A supporting lesson was taught from the ASTRO-1 control center in Huntsville.

text: The Microwave Theory and Techniques Society focuses on the theory and applications of radio-frequency (HF, VHF/UHF, microwave, millimeter-wave and terahertz), guided-wave and wireless technologies, as they relate to nanostructures, devices, integrated circuits, multi-circuit assemblies, components, packages, transmission lines, sub-systems, and systems involving the generation, amplification, processing, modulation, control, transmission, reception, detection and demodulation, and effects of electromagnetic energy transport. It also includes the interaction & interface of microwave signals with digital & optical circuitry & interconnecting transmission media. Examples include optical waves in suitably confined structures, as well as the applications of acoustic, magnetic, & plasmonic waves to microwave systems.Radio frequency (RF) is a term that refers to signals and associated currents having characteristics such that, if the current is input to an antenna, an electromagnetic (EM) field is generated suitable for wireless broadcasting and/or communications, radar, etc. These frequencies cover a significant portion of the electromagnetic radiation spectrum, extending from about 9 kHz, the lowest allocated wireless communications frequency (if it were audible it would be within the range of human hearing), to thousands of gigahertz (GHz). The discipline of microwave theory & techniques applies physical and mathematical principles to analyze devices, components and structures that interact with electromagnetic fields and often have dimensions representing a significant fraction of a wavelength, or when in-circuit wave propagation effects need to be considered.The Society's focus shall include scientific, technical, and industrial activities, subject to timely modifications approved by the IEEE Technical Advisory Board. Technical Committee focus areas of interest include microwave and millimeter-wave materials, solid state devices and integrated circuits, filters, passive components and packaging, microwave acoustics and photonics, high power and low noise techniques, frequency conversion, field theory, and computer aided design and measurements. In addition, the Society is involved in terahertz technology, ultra-wide band and microwave systems, and multidisciplinary activities such as RF microelectromechanical (RFMEMS) devices, radio frequency identification devices (RFIDs), digital signal processing, biological effects and medical applications, and business issues.

text: After radio waves were discovered in 1887, the first generation of radio transmitter, the spark gap transmitters, produced strings of damped waves, pulses of radio waves which died out to zero quickly.   By the 1890s it was realized that damped waves had disadvantages; their energy was spread over a broad frequency bandwidth so transmitters on different frequencies interfered with each other,  and they could not be modulated with an audio signal to transmit sound.  Efforts were made to invent transmitters that would produce continuous waves, a sinusoidal alternating current at a single frequency.

text: After

text: radio wave

text: s were discovered in 1887, the first generation of

text: radio transmitter

text: , the

text: spark gap transmitter

text: s, produced strings of

text: damped wave

text: s, pulses of radio waves which died out to zero quickly.   By the 1890s it was realized that damped waves had disadvantages; their energy was spread over a broad

text: frequency

text: bandwidth

text: so transmitters on different frequencies interfered with each other,  and they could not be

text: modulated

text: with an audio signal to transmit sound.  Efforts were made to invent transmitters that would produce

text: continuous wave

text: s, a sinusoidal alternating current at a single frequency.

text: Max became a celebrity outside the television series. He was the spokesman for New Coke (after the return of Coca-Cola Classic), delivering the slogan "Catch the wave!" (in his trademark staccato, stuttering playback as "C-c-catch the wave!"). In the UK, Max appeared in television commercials for Radio Rentals. He also hosted an interview show on the Cinemax cable channel, called The Original Max Talking Headroom Show.

text: Max became a celebrity outside the television series. He was the

text: spokesman

text: for

text: New Coke

text: (after the return of

text: Coca-Cola Classic

text: ), delivering the slogan "Catch the wave!" (in his trademark staccato, stuttering playback as "C-c-catch the wave!"). In the UK, Max appeared in television commercials for

text: Radio Rentals

text: . He also hosted an interview show on the

text: Cinemax

text: cable channel, called The Original Max Talking Headroom Show.

text: AM radio signals can be severely disrupted in large urban centres by metal structures, tall buildings and sources of radio frequency interference (RFI) and electrical noise, such as electrical motors, fluorescent lights, or lightning.  As a result, AM radio in many countries has lost its dominance as a music broadcasting service, and in many cities is now relegated to news, sports, religious and talk radio stations. Some musical genres – particularly country, oldies, nostalgia and ethnic music – survive on AM, especially in areas where FM frequencies are in short supply or in thinly populated or mountainous areas where FM coverage is poor.

text: AM radio signals can be severely disrupted in large urban centres by metal structures, tall buildings and sources of

text: radio frequency interference

text: (RFI) and electrical noise, such as electrical motors, fluorescent lights, or lightning.  As a result, AM radio in many countries has lost its dominance as a music broadcasting service, and in many cities is now relegated to news, sports, religious and

text: talk radio

text: stations. Some musical genres – particularly country, oldies, nostalgia and ethnic music – survive on AM, especially in areas where

text: FM frequencies

text: are in short supply or in thinly populated or mountainous areas where FM coverage is poor.

text: The broadcasting station is usually associated with wireless transmission, though in practice broadcasting transmission (sound and television) take place using both wires and radio waves. The point of this is that anyone with the appropriate receiving technology can receive the broadcast.

text: The broadcasting station is usually associated with wireless transmission, though in practice broadcasting transmission (sound and television) take place using both wires and

text: radio wave

text: s. The point of this is that anyone with the appropriate receiving technology can receive the broadcast.

text: Visible and infrared light waves are much shorter than radio frequency waves. Their use to transmit data is referred to as free-space optical communication. Being short, light waves can be focused or collimated with a small lens/antenna, and to a much higher degree than radio waves. Thus, a receiving device can recover a greater portion of the transmitted signal.

text: Visible and infrared light waves are much shorter than radio frequency waves. Their use to transmit data is referred to as

text: free-space optical communication

text: . Being short, light waves can be focused or collimated with a small lens/antenna, and to a much higher degree than radio waves. Thus, a receiving device can recover a greater portion of the transmitted signal.

text: Radio waves of frequency less than about 7 MHz can become trapped in magnetic field-aligned ionization ducts with L values (distance from the center of the earth to the field line at the magnetic equator) less than about 4. These waves after being trapped can propagate to the opposite hemisphere where they become reflected in the topside ionosphere. They can return along the duct, leave it, and propagate to the receiver.

text: A 12-hour webathon to benefit the Bob Hope Hollywood USO was hosted by and featured on Stickam. Popular Los Angeles DJ Gary Bryan emceed the event which featured live interactive chatting with US soldiers based in Iraq. The event was organized by several CBS radio stations in Southern California, including KRTH-FM (K-Earth 101), KTWV-FM (94.7 The WAVE), KLSX-FM (91.7), KFWB-AM (News 980) and KNX-AM (News 1070). Stickam featured the event on Stickam.com and provided players that were embedded on many additional sites, including  MilitaryConnection.com, Newsblaze.com, TalkingWithHeroes.com and RealMilitaryFlix.com.

text: On the AM band there are few licensed stations left, all of which are state run. Unlicensed broadcasting is tolerated as the majority of listeners have abandoned the MW band. A number of unlicensed radio stations have taken advantage of that, thus avoiding the "crowded" FM band. A number of pirate radio enthusiasts use the expanded upper part of the AM band (1600–1710 KHz) for "experimental" transmissions. When MW pirate radio broadcasting occurred, there was a format division between the AM and FM, in Athens and Thessaloniki. On the MW/AM band most radio pirates in Athens were broadcasting foreign music (pop and rock) whereas in FM most radio pirates broadcast Greek popular music. In Thessaloniki, and most of the rest of Greece, on MW/AM pirates were playing Greek popular music, and foreign pop and rock on FM. Currently, with several exceptions, nearly all MW/AM radio pirates play Greek popular music to a limited audience.

text: On the AM band there are few licensed stations left, all of which are state run. Unlicensed broadcasting is tolerated as the majority of listeners have abandoned the MW band. A number of unlicensed radio stations have taken advantage of that, thus avoiding the "crowded" FM band. A number of pirate radio enthusiasts use the expanded upper part of the AM band (1600–1710 KHz) for "experimental" transmissions. When MW pirate radio broadcasting occurred, there was a format division between the AM and FM, in

text: Athens

text: and

text: Thessaloniki

text: . On the MW/AM band most radio pirates in

text: Athens

text: were broadcasting foreign music (pop and rock) whereas in FM most radio pirates broadcast Greek popular music. In

text: Thessaloniki

text: , and most of the rest of Greece, on MW/AM pirates were playing Greek popular music, and foreign pop and rock on FM. Currently, with several exceptions, nearly all MW/AM radio pirates play Greek popular music to a limited audience.

text: The Gibraltar Broadcasting Corporation operates a television and radio station on UHF, VHF and medium-wave. The radio service is also internet-streamed. Special events and the daily news bulletin are streamed in video. The other local radio service is operated by the British Forces Broadcasting Service which also provides a limited cable television network to HM Forces. The largest and most frequently published newspaper is the Gibraltar Chronicle, Gibraltar's oldest established daily newspaper and the world's second oldest English language newspaper to have been in print continuously with daily editions six days a week. Panorama is published on weekdays, and 7 Days, The New People, and Gibsport are weekly.

text: The

text: Gibraltar Broadcasting Corporation

text: operates a television and radio station on UHF, VHF and medium-wave. The radio service is also internet-streamed. Special events and the daily news bulletin are streamed in video. The other local radio service is operated by the

text: British Forces Broadcasting Service

text: which also provides a limited cable television network to HM Forces. The largest and most frequently published newspaper is the

text: Gibraltar Chronicle

text: , Gibraltar's oldest established daily newspaper and the world's second oldest English language newspaper to have been in print continuously with daily editions six days a week.

text: Panorama

text: is published on weekdays, and 7 Days, The New People, and Gibsport are weekly.

text: There are currently 260 AM broadcasting and 1150 FM broadcasting radio stations in Argentina. Radio remains an important medium in Argentina. Music and youth variety programs dominate FM formats; news, debate, and sports are AM radio's primary broadcasts. Amateur radio is widespread in the country.

text: There are currently 260

text: AM broadcasting

text: and 1150

text: FM broadcasting

text: radio stations in Argentina. Radio remains an important medium in Argentina. Music and youth variety programs dominate FM formats; news, debate, and sports are AM radio's primary broadcasts.

text: Amateur radio

text: is widespread in the country.

text: The sources of gravitational waves described above are in the low-frequency end of the gravitational-wave spectrum (10 to 10 Hz). An astrophysical source at the high-frequency end of the gravitational-wave spectrum (above 10 Hz and probably 10 Hz) generates relic gravitational waves that are theorized to be faint imprints of the Big Bang like the cosmic microwave background (see gravitational wave background). At these high frequencies it is potentially possible that the sources may be "man made" that is, gravitational waves generated and detected in the laboratory.

text: The sources of gravitational waves described above are in the low-frequency end of the gravitational-wave spectrum (10 to 10 Hz). An astrophysical source at the high-frequency end of the gravitational-wave spectrum (above 10 Hz and probably 10 Hz) generates relic gravitational waves that are theorized to be faint imprints of the Big Bang like the cosmic microwave background (see

text: gravitational wave background

text: ). At these high frequencies it is potentially possible that the sources may be "man made" that is, gravitational waves generated and detected in the laboratory.

text: XEE-AM/XHE-FM is an AM-FM combo radio station that serves the state of Durango with Radio Fórmula programming.

text: XEE-AM/XHE-FM is an AM-FM combo

text: radio station

text: that serves the state of

text: Durango

text: with

text: Radio Fórmula

text: programming.

text: Local radio broadcasters include: WROW 590 AM, WGY 810 AM, WABY 900 AM, WMML 1230 AM, WENU 1410 AM, and WWSC 1450 AM; WVCR 88.3 FM, WMHT-FM 89.1 FM, WLJH 90.7 FM, WSPN 91.1 FM WLJH 90.7 FM, WFLY 92.3 FM, WGFR 92.7 FM, (college radio station), WEZF 92.9 FM, WYAI 93.7 FM, WNYV 94.1 FM, WBAR 94.7 FM, WYJB 95.5 FM, WCQL 95.9 FM, WDCD 96.7 FM, WTRY-FM 98.3 FM, WCKM-FM 98.5 FM, WRVE 99.5 FM, WKBE 100.3 FM, WJKE 101.3 FM, WNYQ 101.7 FM, WKKF 102.3 FM, WQBJ 103.5 FM,  WAMC 103.9 FM WTMM-FM 104.5 FM, WQSH 105.7 FM, WPYX 106.5 FM, WFFG 107.1 FM, WGNA 107.7 FM. WAMC 90.3 FM and North Country Public Radio 97.3 FM are the public radio stations.

text: Local radio broadcasters include:

text: WROW

text: 590 AM,

text: WGY

text: 810 AM,

text: WABY

text: 900 AM,

text: WMML

text: 1230 AM,

text: WENU

text: 1410 AM, and

text: WWSC

text: 1450 AM;

text: WVCR

text: 88.3 FM, WMHT-FM 89.1 FM,

text: WLJH

text: 90.7 FM,

text: WSPN

text: 91.1 FM

text: WLJH

text: 90.7 FM,

text: WFLY

text: 92.3 FM,

text: WGFR

text: 92.7 FM, (

text: college radio

text: station),

text: WEZF

text: 92.9 FM,

text: WYAI

text: 93.7 FM,

text: WNYV

text: 94.1 FM,

text: WBAR

text: 94.7 FM,

text: WYJB

text: 95.5 FM,

text: WCQL

text: 95.9 FM,

text: WDCD

text: 96.7 FM,

text: WTRY-FM

text: 98.3 FM,

text: WCKM-FM

text: 98.5 FM,

text: WRVE

text: 99.5 FM,

text: WKBE

text: 100.3 FM,

text: WJKE

text: 101.3 FM,

text: WNYQ

text: 101.7 FM,

text: WKKF

text: 102.3 FM,

text: WQBJ

text: 103.5 FM,

text: WAMC

text: 103.9 FM

text: WTMM-FM

text: 104.5 FM,

text: WQSH

text: 105.7 FM,

text: WPYX

text: 106.5 FM,

text: WFFG

text: 107.1 FM,

text: WGNA

text: 107.7 FM.

text: WAMC

text: 90.3 FM and North Country Public Radio 97.3 FM are the public radio stations.

text: The beam described above is generated by starting with a broadband light source—one containing the full spectrum of wavelengths to be measured. The light shines into a Michelson interferometer—a certain configuration of mirrors, one of which is moved by a motor. As this mirror moves, each wavelength of light in the beam is periodically blocked, transmitted, blocked, transmitted, by the interferometer, due to wave interference. Different wavelengths are modulated at different rates, so that at each moment, the beam coming out of the interferometer has a different spectrum.

text: The beam described above is generated by starting with a

text: broadband

text: light source—one containing the full spectrum of wavelengths to be measured. The light shines into a

text: Michelson interferometer

text: —a certain configuration of mirrors, one of which is moved by a motor. As this mirror moves, each wavelength of light in the beam is periodically blocked, transmitted, blocked, transmitted, by the interferometer, due to

text: wave interference

text: . Different wavelengths are modulated at different rates, so that at each moment, the beam coming out of the interferometer has a different spectrum.

text: Skywave modes of radio communication operate by bending (refracting) radio waves (electromagnetic radiation) through the Ionosphere. During the "peaks" of the solar cycle, the ionosphere becomes increasingly ionized by solar photons and cosmic rays. This affects the propagation of the radio wave in complex ways that can either facilitate or hinder communications. Forecasting of skywave modes is of considerable interest to commercial marine and aircraft communications, amateur radio operators and shortwave broadcasters. These users occupy frequencies within the High Frequency or 'HF' radio spectrum that are most affected by these solar and ionospheric variances. Changes in solar output affect the maximum usable frequency, a limit on the highest frequency usable for communications.

text: Skywave modes of radio communication operate by bending (

text: refracting

text: ) radio waves (

text: electromagnetic radiation

text: ) through the

text: Ionosphere

text: . During the "peaks" of the solar cycle, the ionosphere becomes increasingly ionized by

text: solar photons

text: and

text: cosmic rays

text: . This affects the

text: propagation

text: of the radio wave in complex ways that can either facilitate or hinder communications. Forecasting of skywave modes is of considerable interest to commercial

text: marine

text: and

text: aircraft

text: communications

text: amateur radio operators

text: and

text: shortwave

text: broadcasters

text: . These users occupy frequencies within the

text: High Frequency

text: or 'HF' radio spectrum that are most affected by these solar and ionospheric variances. Changes in solar output affect the

text: maximum usable frequency

text: , a limit on the highest

text: frequency

text: usable for communications.

text: For a given frequency, the wavelength of an electromagnetic wave is affected by the material in which it is propagating. The vacuum wavelength (the wavelength that a wave of this frequency would have if it were propagating in vacuum) is

text: Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Like all other electromagnetic waves, they travel at the speed of light. Naturally occurring radio waves are made by lightning, or by certain astronomical objects. Artificially generated radio waves are used for fixed and mobile radio communication, broadcasting, radar and other navigation systems, satellite communication, computer networks and innumerable other applications. In addition, almost any wire carrying alternating current will radiate some of the energy away as radio waves; these are mostly termed interference. Different frequencies of radio waves have different propagation characteristics in the Earth's atmosphere; long waves may bend at the rate of the curvature of the Earth and may cover a part of the Earth very consistently, shorter waves travel around the world by multiple reflections off the ionosphere and the Earth. Much shorter wavelengths bend or reflect very little and travel along the line of sight.

text: In addition, there are more than 10 radio channels most of them broadcasting in the medium waves, except for San'a radio channel that also broadcasts in the short waves, and locally the FM.

text: In addition, there are more than 10 radio channels most of them

text: broadcasting

text: in the

text: medium wave

text: s, except for San'a

text: radio channel

text: that also broadcasts in the

text: short wave

text: s, and locally the

text: FM

text: Radio-Science Publications ceased operations with the August 1931 issues. Bernarr Macfadden's newly formed Teck Publishing Corporation took over with the September 1931 issue. Laurence Cockaday became the editor; the format remained the same but the advances in radio and television broadened the topics covered. A common item in all radio magazines was a list of broadcast stations and short wave stations. In 1934 the covers had black-and-white photos. Color illustrations returned in 1936.

text: Radio-Science Publications ceased operations with the August 1931 issues.

text: Bernarr Macfadden

text: 's newly formed Teck Publishing Corporation took over with the September 1931 issue. Laurence Cockaday became the editor; the format remained the same but the advances in radio and television broadened the topics covered. A common item in all radio magazines was a list of broadcast stations and short wave stations. In 1934 the covers had black-and-white photos. Color illustrations returned in 1936.

text: Other systems similar to radar make use of other parts of the electromagnetic spectrum. One example is "lidar", which uses ultraviolet, visible, or near infrared light from lasers rather than radio waves.

text: Other systems similar to radar make use of other parts of the

text: electromagnetic spectrum

text: . One example is "

text: lidar

text: ", which uses ultraviolet, visible, or near infrared light from

text: laser

text: s rather than radio waves.

text: Radio broadcast stations:AM 1, FM 0, shortwave 0 (2011) - The Tuvalu Media Department of the Government of Tuvalu operates Radio Tuvalu, which broadcasts on the AM frequency. In 2011 the Japanese government provided financial support to construct a new AM broadcast studio. The new AM radio transmitter on Funafuti replaced the FM radio service to the outer islands and freed up satellite bandwidth for mobile services.

text: Radio

text: broadcast stations:

text: AM

text: FM

text: shortwave

text: 0 (2011) - The

text: Tuvalu Media Department

text: of the Government of Tuvalu operates Radio Tuvalu, which broadcasts on the AM frequency. In 2011 the Japanese government provided financial support to construct a new AM broadcast studio. The new AM radio transmitter on Funafuti replaced the FM radio service to the outer islands and freed up satellite bandwidth for mobile services.

text: At this point in time the medium wave band had become unpopular with radio groups and the majority of new stations were awarded an FM licence only, even when an AM licence was jointly available.

text: At this point in time the

text: medium wave

text: band had become unpopular with radio groups and the majority of new stations were awarded an FM licence only, even when an AM licence was jointly available.

text: If the free surface of a liquid is disturbed, waves are produced on the surface. These waves are not elastic waves due to any elastic force; they are gravity waves caused by the force of gravity tending to bring the surface of the disturbed liquid back to its horizontal level. Momentum causes the wave to overshoot, thus oscillating and spreading the disturbance to the neighboring portions of the surface. The velocity of the surface waves varies as the square root of the wavelength if the liquid is deep; therefore long waves on the sea go faster than short ones. Very minute waves or ripples are not due to gravity but to capillary action, and have properties different from those of the longer ocean surface waves,because the surface is increased in area by the ripples and the capillary forces are in this case large compared with the gravitational forces.Capillary ripples are damped both by sub-surface viscosity and by surface rheology.

text: If the free surface of a liquid is disturbed,

text: wave

text: s are produced on the surface. These waves are not

text: elastic waves

text: due to any

text: elastic force

text: ; they are

text: gravity wave

text: s caused by the force of gravity tending to bring the surface of the disturbed liquid back to its horizontal level.

text: Momentum

text: causes the wave to

text: overshoot

text: , thus oscillating and spreading the disturbance to the neighboring portions of the surface. The velocity of the surface waves varies as the square root of the

text: wavelength

text: if the liquid is deep; therefore

text: long waves

text: on the sea go faster than short ones. Very minute waves or ripples are not due to gravity but to

text: capillary action

text: , and have properties different from those of the longer

text: ocean surface waves

text: ,because the surface is increased in area by the ripples and the capillary forces are in this case large compared with the gravitational forces.Capillary ripples are damped both by sub-surface

text: viscosity

text: and by

text: surface rheology

text: An antenna (or aerial) is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver. In transmission, a radio transmitter supplies an electric current oscillating at radio frequency (i.e. high frequency AC) to the antenna's terminals, and the antenna radiates the energy from the current as electromagnetic waves (radio waves). In reception, an antenna intercepts some of the power of an electromagnetic wave in order to produce a tiny voltage at its terminals, that is applied to a receiver to be amplified.  Some antennas can be used for both transmitting and receiving, even simultaneously, depending on the connected equipment.

text: An antenna (or aerial) is an electrical device which converts

text: electric current

text: s into

text: radio wave

text: s, and vice versa. It is usually used with a

text: radio transmitter

text: or

text: radio receiver

text: . In

text: transmission

text: , a radio transmitter supplies an electric current oscillating at radio frequency (i.e. high frequency AC) to the antenna's terminals, and the antenna radiates the energy from the current as

text: electromagnetic wave

text: s (radio waves). In reception, an antenna intercepts some of the power of an electromagnetic wave in order to produce a tiny voltage at its terminals, that is applied to a receiver to be

text: amplified

text: .  Some antennas can be used for both transmitting and receiving, even simultaneously, depending on the connected equipment.

text: A system based on radio waves was briefly considered but rejected because the signals could easily travel through walls and could inadvertently change the channel on a neighbor's television. Furthermore, the marketing people at Zenith desired a remote control which did not require batteries, as it was perceived at the time that if the battery died, the customer might think something was wrong with the television set itself.

text: A system based on

text: radio waves

text: was briefly considered but rejected because the signals could easily travel through walls and could inadvertently change the channel on a neighbor's television. Furthermore, the marketing people at Zenith desired a remote control which did not require batteries, as it was perceived at the time that if the battery died, the customer might think something was wrong with the television set itself.

text: In the early years of the 20th century, before modern AM or FM radio transmission was developed, radio transmitters communicated information by radiotelegraphy; the transmitter was switched off and on by the operator with a telegraph key, producing pulses of radio waves, to spell out text messages in Morse code.  Around 1905 the first continuous wave radio transmitters began to replace the earlier spark transmitters.  The Morse code signal of the spark transmitter consisted of pulses of radio waves called damped waves which repeated at an audio rate, so they were audible as a buzz or tone in a receiver's earphones.   In contrast the new continuous wave transmitters produced a signal consisting of pulses of continuous waves, unmodulated sinusoidal carrier waves, which were inaudible in the earphones.   So to receive this new modulation method, the receiver had to produce a tone during the pulses of carrier.

text: In the early years of the 20th century, before modern

text: AM

text: or

text: FM

text: radio transmission was developed, radio transmitters communicated information by

text: radiotelegraphy

text: ; the transmitter was switched off and on by the operator with a

text: telegraph key

text: , producing pulses of radio waves, to spell out text messages in

text: Morse code

text: .  Around 1905 the first

text: continuous wave

text: radio transmitter

text: s began to replace the earlier

text: spark transmitters

text: .  The Morse code signal of the spark transmitter consisted of pulses of radio waves called

text: damped wave

text: s which repeated at an audio rate, so they were audible as a buzz or tone in a receiver's earphones.   In contrast the new continuous wave transmitters produced a signal consisting of pulses of

text: continuous wave

text: s, unmodulated sinusoidal

text: carrier wave

text: s, which were inaudible in the earphones.   So to receive this new modulation method, the receiver had to produce a tone during the pulses of carrier.

text: A communications receiver is a type of radio receiver used as a component of a radio communication link.   This is in contrast to a broadcast receiver which is used to receive radio broadcasts.  The difference between the two is that broadcast receivers only receive broadcast bands, such as the medium wave and/or longwave AM broadcast bands and the VHF FM broadcast band,  while a communication receiver receives a wider part of the radio spectrum not used for broadcasting, that includes the shortwave bands.   They are often used with a radio transmitter as part of a two way radio link for shortwave radio or amateur radio communication, although they are also used for shortwave listening.

text: A communications receiver is a type of

text: radio receiver

text: used as a component of a radio communication link.   This is in contrast to a broadcast receiver which is used to receive

text: radio broadcasts

text: .  The difference between the two is that broadcast receivers only receive

text: broadcast band

text: s, such as the

text: medium wave

text: and/or

text: longwave

text: AM broadcast bands and the VHF

text: FM broadcast band

text: ,  while a communication receiver receives a wider part of the radio spectrum not used for broadcasting, that includes the

text: shortwave band

text: s.   They are often used with a

text: radio transmitter

text: as part of a

text: two way radio

text: link for

text: shortwave radio

text: or

text: amateur radio

text: communication, although they are also used for

text: shortwave listening

text: Founded in 1993 emitted in short-wave and was the international radio ERT, which emitted from Thessaloniki, like the other three radio programs ERT. The third radio belonged to ERT3, the NRA and the ERT and emitted together with the two radio programs of EPA in short-wave and not the FM, such as three radio stations ERT3 (102 FM, 9,58 FM and EPA Sports Thessaloniki).

text: Founded in 1993 emitted in short-wave and was the international radio ERT, which emitted from Thessaloniki, like the other three radio programs ERT. The third radio belonged to ERT3, the NRA and the ERT and emitted together with the two radio programs of EPA in short-wave and not the FM, such as three radio stations

text: 102 FM

text: 9,58 FM

text: and

text: EPA Sports Thessaloniki

text: An imaging radar is a kind of radar equipment which can be used for imaging. A typical radar technology includes emitting radio waves, receiving their reflection, and using this information to generate data. For an imaging radar, the returning waves are used to create an image. When the radio waves reflect off objects, this will make some changes in the radio waves and can provide data about the objects, including how far the waves traveled and what kind of objects they encountered. Using the acquired data, a computer can create a 3-D or 2-D image of the target.

text: In 1952 a new version of the Ovaltineys' show was aired once more at 6:15 PM on Sunday evenings over Radio Luxembourg on its new 208 Medium Wave transmitter.

text: Radio astronomy uses radiation outside the visible range with wavelengths greater than approximately one millimeter. Radio astronomy is different from most other forms of observational astronomy in that the observed radio waves can be treated as waves rather than as discrete photons. Hence, it is relatively easier to measure both the amplitude and phase of radio waves, whereas this is not as easily done at shorter wavelengths.

text: Radio astronomy uses radiation outside the visible range with

text: wavelength

text: s greater than approximately one millimeter. Radio astronomy is different from most other forms of observational astronomy in that the observed

text: radio wave

text: s can be treated as

text: wave

text: s rather than as discrete

text: photon

text: s. Hence, it is relatively easier to measure both the

text: amplitude

text: and

text: phase

text: of radio waves, whereas this is not as easily done at shorter wavelengths.

text: Unlike other wire antennas such as dipole or monopole antennas which act as resonators, with the radio currents traveling in both directions along the element, bouncing back and forth between the ends as standing waves, the Beverage antenna is a traveling wave antenna; the radio frequency current travels in one direction along the wire, in the same direction as the radio waves.  The lack of resonance gives it a wider bandwidth than resonant antennas.  It receives vertically polarized radio waves, but unlike other vertically polarized antennas it is suspended close to the ground, and requires some resistance in the ground to work.

text: Unlike other wire antennas such as

text: dipole

text: or

text: monopole antenna

text: s which act as

text: resonators

text: , with the radio currents traveling in both directions along the element, bouncing back and forth between the ends as

text: standing wave

text: s, the Beverage antenna is a

text: traveling wave antenna

text: ; the radio frequency current travels in one direction along the wire, in the same direction as the radio waves.  The lack of resonance gives it a wider

text: bandwidth

text: than

text: resonant

text: antennas.  It receives

text: vertically polarized

text: radio waves, but unlike other vertically polarized antennas it is suspended close to the ground, and requires some

text: resistance

text: in the ground to work.

text: Early in 1980, influential radio consultant Lee Abrams wrote a memo saying that with a few exceptions, "we're not going to be seeing many of the new wave circuit acts happening very big over here (in America). As a movement, we don't expect it to have much influence." Lee Ferguson, a consultant to KWST, said in an interview that Los Angeles radio stations were banning disc jockeys from using the term and noted, "Most of the people who call music new wave are the ones looking for a way not to play it." Despite the success of Devo's socially critical but widely misperceived song "Whip It", second albums by artists who had successful debut albums, along with newly signed artists, failed to sell, and radio pulled most new wave programming.

text: Early in 1980, influential radio consultant

text: Lee Abrams

text: wrote a memo saying that with a few exceptions, "we're not going to be seeing many of the new wave circuit acts happening very big over here (in America). As a movement, we don't expect it to have much influence." Lee Ferguson, a consultant to

text: KWST

text: , said in an interview that Los Angeles radio stations were banning disc jockeys from using the term and noted, "Most of the people who call music new wave are the ones looking for a way not to play it." Despite the success of

text: Devo

text: 's socially critical but widely misperceived song "

text: Whip It

text: ", second albums by artists who had successful debut albums, along with newly signed artists, failed to sell, and radio pulled most new wave programming.

text: S/PDIF –Sacrificial anode –Sampling frequency –Scalar field –Scanner –Scanning electron microscope –SCART –Schematic –Schumann resonance –Scrambler –Screen –SECAM –Second audio program –Second-order intercept point –Security management –Self-clocking signal –Self-synchronizing code –Semiautomatic switching system –Semiconductor device –Semiconductor –Sensitivity –Sensor Networks –Separate channel signaling –Serial access –Serial ATA –Serial Peripheral Interface Bus –Serial transmission –Series and parallel circuits –Shadow loss –Shannon limit –Shannon's theorem –Short circuit –Shortwave –Shot noise –Shrinking generator –Side lobe –Sideband –Sidereal time –Siemens –Signal (information theory) –Signal compression –Signal processing gain –Signal processing –Signal reflection –Signal transition –Signal-to-crosstalk ratio –Signal-to-noise ratio –Signature block –Significant condition –Silicon bandgap temperature sensor –Silicon –Simplex circuit –Simplex signaling –Sinc filter –Single frequency networks –Single-phase electric power –Single-frequency signaling –Single-polarized antenna –Single-sideband modulation –Skew (antenna) –Skin effect –Skip zone –Skywave –Slant range –Slewing –Slew rate -Slot antenna –Slow-scan television –Software-defined radio –Solar cell –Soldering –Solenoid –Sound card –Space diversity –Space tether –Spark gap –Specific detectivity –Specification –Speckle pattern –Spectral width –Spectrum –Spectrum analyzer –Speed of light –Speed of service –SPICE –Spill-forward feature –Spillover –Spin glass –Spot beam –Spread spectrum –Spurious emission –Squelch –Standard telegraph level –Standard test signal –Standard test tone –Standing wave ratio –Standing wave –Starpath Supercharger –Start signal –Start-stop transmission –Static electricity –Steady-state condition –Step-index profile –Stoletov's law -Stop signal –Stopband –Store-and-forward switching center –Stressed environment –Strobe light –Stroke speed –Subcarrier –Subtractive synthesis –Sudden ionospheric disturbance –Supercomputer –Superconductivity –Superheterodyne receiver –Superparamagnetism –Superposition theorem -Supervisory program –Suppressed carrier transmission –Surface wave –Surface-mount technology –Surveillance device –Survivability –S-Video –Switch –Switched-mode power supply –Synchronism –Synchronization –Synchronizing –Synchronous network –Synchronous optical networking –Synthesizer –System integrity –Systems control

text: S/PDIF

text: Sacrificial anode

text: Sampling frequency

text: Scalar field

text: Scanner

text: Scanning electron microscope

text: SCART

text: Schematic

text: Schumann resonance

text: Scrambler

text: Screen

text: SECAM

text: Second audio program

text: Second-order intercept point

text: Security management

text: Self-clocking signal

text: Self-synchronizing code

text: Semiautomatic switching system

text: Semiconductor device

text: Semiconductor

text: Sensitivity

text: Sensor Networks

text: Separate channel signaling

text: Serial access

text: Serial ATA

text: Serial Peripheral Interface Bus

text: Serial transmission

text: Series and parallel circuits

text: Shadow loss

text: Shannon limit

text: Shannon's theorem

text: Short circuit

text: Shortwave

text: Shot noise

text: Shrinking generator

text: Side lobe

text: Sideband

text: Sidereal time

text: Siemens

text: Signal (information theory)

text: Signal compression

text: Signal processing gain

text: Signal processing

text: Signal reflection

text: Signal transition

text: Signal-to-crosstalk ratio

text: Signal-to-noise ratio

text: Signature block

text: Significant condition

text: Silicon bandgap temperature sensor

text: Silicon

text: Simplex circuit

text: Simplex signaling

text: Sinc filter

text: Single frequency networks

text: Single-phase electric power

text: Single-frequency signaling

text: Single-polarized antenna

text: Single-sideband modulation

text: Skew (antenna)

text: Skin effect

text: Skip zone

text: Skywave

text: Slant range

text: Slewing

text: Slew rate

text: Slot antenna

text: Slow-scan television

text: Software-defined radio

text: Solar cell

text: Soldering

text: Solenoid

text: Sound card

text: Space diversity

text: Space tether

text: Spark gap

text: Specific detectivity

text: Specification

text: Speckle pattern

text: Spectral width

text: Spectrum

text: Spectrum analyzer

text: Speed of light

text: Speed of service

text: SPICE

text: Spill-forward feature

text: Spillover

text: Spin glass

text: Spot beam

text: Spread spectrum

text: Spurious emission

text: Squelch

text: Standard telegraph level

text: Standard test signal

text: Standard test tone

text: Standing wave ratio

text: Standing wave

text: Starpath Supercharger

text: Start signal

text: Start-stop transmission

text: Static electricity

text: Steady-state condition

text: Step-index profile

text: Stoletov's law

text: Stop signal

text: Stopband

text: Store-and-forward switching center

text: Stressed environment

text: Strobe light

text: Stroke speed

text: Subcarrier

text: Subtractive synthesis

text: Sudden ionospheric disturbance

text: Supercomputer

text: Superconductivity

text: Superheterodyne receiver

text: Superparamagnetism

text: Superposition theorem

text: Supervisory program

text: Suppressed carrier transmission

text: Surface wave

text: Surface-mount technology

text: Surveillance

text: device –

text: Survivability

text: S-Video

text: Switch

text: Switched-mode power supply

text: Synchronism

text: Synchronization

text: Synchronizing

text: Synchronous network

text: Synchronous optical networking

text: Synthesizer

text: System integrity

text: Systems control

text: In certain physics applications such as in the computation of bands in a periodic volume, it is often the case that the elements of a matrix will be very complicated functions of frequency and wavenumber, and the matrix will be non-singular for most combinations of frequency and wavenumber, but will also be singular for certain specific combinations. By finding which combinations of frequency and wavenumber drive the determinant of the matrix to zero, the propagation characteristics of the medium may be determined. Relations of this type, between frequency and wavenumber, are known as dispersion relations and some physical systems may admit many different kinds of dispersion relations. An example from electromagnetics is the ordinary waveguide, which may admit numerous dispersion relations, each associated with a unique mode of the waveguide. Each propagation mode of the waveguide is known as an eigenfunction solution (or eigenmode solution) to Maxwell's equations in the waveguide. Free space also admits eigenmode (natural mode) solutions (known more commonly as plane waves), but with the distinction that for any given frequency, free space admits a continuous modal spectrum, whereas waveguides have a discrete mode spectrum.  In this case the dispersion relation is linear, as in section 1.2.

text: In certain physics applications such as in the

text: computation of bands in a periodic volume

text: , it is often the case that the elements of a matrix will be very complicated functions of frequency and wavenumber, and the matrix will be non-singular for most combinations of frequency and wavenumber, but will also be singular for certain specific combinations. By finding which combinations of frequency and wavenumber drive the determinant of the matrix to zero, the propagation characteristics of the medium may be determined. Relations of this type, between frequency and wavenumber, are known as dispersion relations and some physical systems may admit many different kinds of dispersion relations. An example from electromagnetics is the ordinary waveguide, which may admit numerous dispersion relations, each associated with a unique mode of the waveguide. Each propagation mode of the waveguide is known as an

text: eigenfunction

text: solution (or eigenmode solution) to Maxwell's equations in the waveguide. Free space also admits eigenmode (natural mode) solutions (known more commonly as plane waves), but with the distinction that for any given frequency, free space admits a continuous modal spectrum, whereas waveguides have a discrete mode spectrum.  In this case the dispersion relation is linear, as in section 1.2.

text: KD Radio Incorporated (KD Radio) purchased KDSK-FM in January 2001.  Having had much success with kdradio.com in California, it was decided to put the massive KD Radio oldies format of 7000 songs on the broadcast sister station, 50-year-old KMIN-AM (980 kHz).  KDSK was a hot country station at this time.  In April 2001 KMIN began streaming its Sound Souvenir's programming on the internet at kmin980.com.  On June 14, 2004 KMIN's Sound Souvenir's format moved over to KDSK-FM.  Due to the Sound Souvenir's strong showing in the ratings, number one in its market, management made the decision to move the format to the stronger KDSK-FM signal.  This move was made after one week of simulcasting the Sound Souvenir's format on both KMIN-AM and KDSK-FM.

text: KD Radio Incorporated (KD Radio) purchased KDSK-FM in January 2001.  Having had much success with kdradio.com in California, it was decided to put the massive KD Radio

text: oldies

text: format of 7000 songs on the broadcast sister station, 50-year-old

text: KMIN-AM

text: kHz

text: ).  KDSK was a hot country station at this time.  In April 2001 KMIN began streaming its Sound Souvenir's programming on the internet at kmin980.com.  On June 14, 2004 KMIN's Sound Souvenir's format moved over to KDSK-FM.  Due to the Sound Souvenir's strong showing in the ratings, number one in its market, management made the decision to move the format to the stronger KDSK-FM signal.  This move was made after one week of simulcasting the Sound Souvenir's format on both KMIN-AM and KDSK-FM.

text: Wavelength is a measure of the distance between repetitions of a shape feature such as peaks, valleys, or zero-crossings, not a measure of how far any given particle moves. For example, in sinusoidal waves over deep water a particle near the water's surface moves in a circle of the same diameter as the wave height, unrelated to wavelength. The range of wavelengths or frequencies for wave phenomena is called a spectrum. The name originated with the visible light spectrum but now can be applied to the entire electromagnetic spectrum as well as to a sound spectrum or vibration spectrum.

text: Wavelength is a measure of the distance between repetitions of a shape feature such as peaks, valleys, or zero-crossings, not a measure of how far any given particle moves. For example, in sinusoidal waves over deep water a particle near the water's surface moves in a circle of the same diameter as the wave height, unrelated to wavelength. The range of wavelengths or frequencies for wave phenomena is called a

text: spectrum

text: . The name originated with the visible light spectrum but now can be applied to the entire

text: electromagnetic spectrum

text: as well as to a

text: sound spectrum

text: or

text: vibration spectrum

text: Beacon Hill A became operational in 1972-3, bringing 625 line PAL colour television to the coverage area of Torbay and south Devon. Beacon Hill B transmits FM radio and DAB radio to the area. In 2007, a third guyed lattice mast was constructed at the site to provide medium wave transmissions for Gold (Exeter/Torbay). The transmitter for Gold was dismantled after the service was discontinued.

text: Beacon Hill A became operational in 1972-3, bringing 625 line

text: PAL

text: colour television to the coverage area of

text: Torbay

text: and south Devon. Beacon Hill B transmits

text: FM radio

text: and

text: DAB radio

text: to the area. In 2007, a third guyed lattice mast was constructed at the site to provide

text: medium wave

text: transmissions for

text: Gold (Exeter/Torbay)

text: . The transmitter for Gold was dismantled after the service was discontinued.

text: All waves and wavelets (child waves) are identified by a globally unique wave id, which is a domain name and an id string. The domain name identifies the wave provider where the wave originated. Waves and wavelets are hosted by the wave provider of the creator. Wavelets in the same wave can be hosted by different wave providers. However, user data is not federated; i.e., not shared with other wave providers. Private reply wavelets are also possible, of which other participants have no knowledge or access. If a private wavelet is sent between users on the same wave provider, it's not federated regardless of where the parent wave is hosted.

text: A dielectric resonator antenna (DRA) is a radio antenna mostly used at microwave frequencies and higher, that consists of a block of ceramic material of various shapes, the dielectric resonator, mounted on a metal surface, a ground plane.  Radio waves are introduced into the inside of the resonator material from the transmitter circuit and bounce back and forth between the resonator walls, forming standing waves.  The walls of the resonator are partially transparent to radio waves, allowing the radio power to radiate into space.

text: A dielectric resonator antenna (DRA) is a radio

text: antenna

text: mostly used at

text: microwave

text: frequencies and higher, that consists of a block of

text: ceramic

text: material of various shapes, the

text: dielectric resonator

text: , mounted on a metal surface, a

text: ground plane

text: .  Radio waves are introduced into the inside of the resonator material from the

text: transmitter

text: circuit and bounce back and forth between the resonator walls, forming

text: standing waves

text: .  The walls of the resonator are partially transparent to radio waves, allowing the radio power to radiate into space.

text: Important basic characteristics of waves are wavelength, amplitude, period, and frequency. Wavelength is the length of the repeating wave shape. Amplitude is the maximum displacement of the particles of the medium, which is determined by the energy of the wave. A period (measured in seconds) is the time for one wave to pass a given point. Frequency of the wave is the number of waves passing a given point in a unit of time. Frequency is measured in hertz (hz); (Hz cycles per second) and is the perceived as pitch. Each complete vibration of a sound wave is called a cycle. Two other physical properties of sound are intensity and duration. Intensity is measured in decibels (dB) and is perceived as loudness.

text: Important basic characteristics of waves are wavelength, amplitude, period, and frequency.

text: Wavelength

text: is the length of the repeating wave shape.

text: Amplitude

text: is the maximum displacement of the particles of the medium, which is determined by the energy of the wave. A period (measured in seconds) is the time for one wave to pass a given point.

text: Frequency

text: of the wave is the number of waves passing a given point in a unit of time. Frequency is measured in

text: hertz (hz)

text: ; (Hz cycles per second) and is the

text: perceived

text: as

text: pitch

text: . Each complete vibration of a sound wave is called a cycle. Two other physical properties of sound are intensity and duration. Intensity is measured in

text: decibels (dB)

text: and is perceived as loudness.

text: with discrete spectrum is measured in a system with normalized wave function

text: with discrete

text: spectrum

text: is measured in a system with normalized

text: wave function

text: As early as 1899, Arnold Sommerfeld published a paper predicting the use of a single cylindrical conductor (wire) to propagate radio frequency energy as a surface wave. Sommerfeld's "wire wave" was of theoretical interest as a propagating mode, but this was decades before technology existed for the generation of sufficiently high radio frequencies for any such experimentation, let alone practical applications. What's more, the solution described an infinite transmission line without consideration of coupling energy into (or out of) it.

text: As early as 1899,

text: Arnold Sommerfeld

text: published a paper predicting the use of a single cylindrical conductor (wire) to propagate

text: radio frequency

text: energy as a

text: surface wave

text: . Sommerfeld's "wire wave" was of theoretical interest as a propagating mode, but this was decades before technology existed for the generation of sufficiently high radio frequencies for any such experimentation, let alone practical applications. What's more, the solution described an infinite transmission line without consideration of coupling energy into (or out of) it.

text: The entire spectrum can be divided into three sections:  audio, ultrasonic, and infrasonic.  The audio range falls between 20 Hz and 20,000 Hz.  This range is important because its frequencies can be detected by the human ear.  This range has a number of applications, including speech communication and music.  The ultrasonic range refers to the very high frequencies: 20,000 Hz and higher.  This range has shorter wavelengths which allow better resolution in imaging technologies.  Medical applications such as ultrasonography and elastography rely on the ultrasonic frequency range.  On the other end of the spectrum, the lowest frequencies are known as the infrasonic range.  These frequencies can be used to study geological phenomena such as earthquakes.

text: The entire spectrum can be divided into three sections:  audio, ultrasonic, and infrasonic.  The audio range falls between 20

text: Hz

text: and 20,000 Hz.  This range is important because its frequencies can be detected by the human ear.  This range has a number of applications, including speech communication and music.  The ultrasonic range refers to the very high frequencies: 20,000 Hz and higher.  This range has shorter wavelengths which allow better resolution in imaging technologies.  Medical applications such as

text: ultrasonography

text: and elastography rely on the ultrasonic frequency range.  On the other end of the spectrum, the lowest frequencies are known as the infrasonic range.  These frequencies can be used to study geological phenomena such as earthquakes.

text: Phase modulation is widely used for transmitting radio waves and is an integral part of many digital transmission coding schemes that underlie a wide range of technologies like WiFi, GSM and satellite television.

text: Phase modulation is widely used for transmitting

text: radio

text: waves and is an integral part of many digital transmission coding schemes that underlie a wide range of technologies like

text: WiFi

text: GSM

text: and

text: satellite television

text: Medium-wave (medium frequency, MF) and short-wave (high frequency, HF) radio signals act differently during daytime and nighttime. During the day, MF signals travel by groundwave, diffracting around the curve of the earth over a distance up to a few hundred kilometers from the signal transmitter. However, after sunset, changes in the ionosphere cause MF signals to travel by skywave, enabling radio stations to be heard much farther from their point of origin than is normal during the day. This phenomenon can be easily observed by scanning the medium wave radio dial at night. As a result, many broadcast stations are required as a condition of license to reduce their broadcasting power significantly (or use directional antennas) after sunset, or even to suspend broadcasting entirely during nighttime hours. Such stations are commonly referred to as daytimers. In Australia medium wave stations are not required to reduce their power at night and consequently stations such as the 50,000-watt 774 ABC Melbourne can be heard in some parts of New Zealand at night.

text: Medium-wave

text: medium frequency

text: , MF) and

text: short-wave

text: high frequency

text: , HF) radio signals act differently during daytime and nighttime. During the day, MF signals travel by

text: groundwave

text: , diffracting around the curve of the earth over a distance up to a few hundred kilometers from the signal transmitter. However, after sunset, changes in the

text: ionosphere

text: cause MF signals to travel by

text: skywave

text: , enabling radio stations to be heard much farther from their point of origin than is normal during the day. This phenomenon can be easily observed by scanning the medium wave radio dial at night. As a result, many broadcast stations are required as a condition of license to reduce their broadcasting power significantly (or use

text: directional antenna

text: s) after sunset, or even to suspend broadcasting entirely during nighttime hours. Such stations are commonly referred to as

text: daytimers

text: . In Australia medium wave stations are not required to reduce their power at night and consequently stations such as the 50,000-watt

text: 774 ABC Melbourne

text: can be heard in some parts of New Zealand at night.

text: Blaupunkt am-fm radio: Installed in place of stock a.m. radio

text: Most television services outside North America are national networks established by a combination of publicly funded broadcasters and commercial broadcasters. Most nations established television networks in a similar way: the first television service in each country was operated by a public broadcaster, often funded by a television licensing fee, and most of them later established a second or even third station providing a greater variety of content. Commercial television services also became available when private companies applied for television broadcasting licenses. Often, each new network would be identified with their channel number, so that individual stations would often be numbered "One," "Two," "Three," and so forth.

text: Most television services outside North America are national networks established by a combination of publicly funded broadcasters and commercial broadcasters. Most nations established television networks in a similar way: the first television service in each country was operated by a

text: public broadcaster

text: , often funded by a television licensing fee, and most of them later established a second or even third station providing a greater variety of content. Commercial television services also became available when private companies applied for television broadcasting licenses. Often, each new network would be identified with their channel number, so that individual stations would often be numbered "One," "Two," "Three," and so forth.

text: The parasitic elements in a Yagi antenna are mounted parallel to the driven element, with all the elements usually in a line perpendicular to the direction of radiation of the antenna.  What effect a parasitic element has on the radiation pattern depends both on its separation from the next element, and on its length.  The driven element of the antenna is usually a half-wave dipole, its length half a wavelength of the radio waves used.  The parasitic elements are of two types.  A "reflector" is slightly longer (around 5%) than a half-wavelength.  It serves to reflect the radio waves in the opposite direction.  A "director" is slightly shorter than a half-wavelength; it serves to increase the radiation in a given direction.  A Yagi antenna may have a reflector on one side of the driven element, and one or more directors on the other side.  If all the elements are in a plane, usually only one reflector is used, because additional ones give little improvement in gain, but sometimes additional reflectors are mounted above and below the plane of the antenna on a vertical bracket at the end.

text: The parasitic elements in a Yagi antenna are mounted parallel to the driven element, with all the elements usually in a line perpendicular to the direction of radiation of the antenna.  What effect a parasitic element has on the radiation pattern depends both on its separation from the next element, and on its length.  The driven element of the antenna is usually a

text: half-wave

text: dipole

text: , its length half a

text: wavelength

text: of the radio waves used.  The parasitic elements are of two types.  A "reflector" is slightly longer (around 5%) than a half-wavelength.  It serves to reflect the radio waves in the opposite direction.  A "director" is slightly shorter than a half-wavelength; it serves to increase the radiation in a given direction.  A Yagi antenna may have a reflector on one side of the driven element, and one or more directors on the other side.  If all the elements are in a plane, usually only one reflector is used, because additional ones give little improvement in gain, but sometimes additional reflectors are mounted above and below the plane of the antenna on a vertical bracket at the end.

text: Now Sitkūnai Radio Station broadcasts on three frequencies in themedium wave band using two transmitters (Russian made Shtorm, 150 kW, installed 1964, and Russian made Vihr, 500 kW, installed 1977) and following antennas: one guyed mast 257 metre tall, two guyed masts 238 metre tall and two masts 150 metre tall. For short wave broadcasting, a Continental 418F 100 kW transmitter is used along with four antennas: three horizontal dipole arrays beamed at 259, 79 and 310 degrees, and a dipole beamed at 259/79 degrees. The station is owned and operated by Lithuanian National Radio and Television Centre.

text: Now Sitkūnai Radio Station broadcasts on three frequencies in themedium wave band using two

text: transmitter

text: s (Russian made Shtorm, 150 kW, installed 1964, and Russian made Vihr, 500 kW, installed 1977) and following

text: antenna

text: s: one guyed

text: mast

text: 257 metre tall, two guyed masts 238 metre tall and two masts 150 metre tall. For short wave broadcasting, a Continental 418F 100 kW transmitter is used along with four antennas: three horizontal dipole arrays beamed at 259, 79 and 310 degrees, and a dipole beamed at 259/79 degrees. The station is owned and operated by

entity_name: Lithuanian National Radio and Television

text: Lithuanian National Radio and Television

text: Centre.

text: In parabolic antennas such as satellite dishes, a feed horn (or feedhorn) is a small horn antenna used to convey radio waves between the transmitter and/or receiver and the parabolic reflector.  In transmitting antennas, it is connected to the transmitter and converts the radio frequency alternating current from the transmitter to radio waves and feeds them to the rest of the antenna, which focuses them into a beam.  In receiving antennas, incoming radio waves are gathered and focused by the antenna's reflector on the feed horn, which converts them to a tiny radio frequency voltage which is amplified by the receiver.  Feed horns are used mainly at microwave (SHF) and higher frequencies.

text: In

text: parabolic antenna

text: s such as

text: satellite dish

text: es, a feed horn (or feedhorn) is a small

text: horn antenna

text: used to convey

text: radio wave

text: s between the

text: transmitter

text: and/or

text: receiver

text: and the

text: parabolic reflector

text: .  In transmitting antennas, it is connected to the

text: transmitter

text: and converts the

text: radio frequency

text: alternating current

text: from the transmitter to

text: radio wave

text: s and feeds them to the rest of the antenna, which focuses them into a beam.  In receiving antennas, incoming radio waves are gathered and focused by the antenna's reflector on the feed horn, which converts them to a tiny radio frequency voltage which is amplified by the

text: receiver

text: .  Feed horns are used mainly at

text: microwave

text: SHF

text: ) and higher

text: frequencies

text: If electromagnetic waves travelling through one material meet another material, having a different dielectric constant or diamagnetic constant from the first,the waves will reflect or scatter from the boundary between the materials. This means that a solid object in air or in a vacuum, or a significant change in atomic density between the object and what is surrounding it, will usually scatter radar (radio) waves from its surface. This is particularly true for electrically conductive materials such as metal and carbon fibre, making radar well-suited to the detection of aircraft and ships. Radar absorbing material, containing resistive and sometimes magnetic substances, is used on military vehicles to reduce radar reflection. This is the radio equivalent of painting something a dark colour so that it cannot be seen by the eye at night.

text: If

text: electromagnetic waves

text: travelling through one material meet another material, having a different

text: dielectric constant

text: or

text: diamagnetic constant

text: from the first,the waves will reflect or scatter from the boundary between the materials. This means that a solid object in

text: air

text: or in a

text: vacuum

text: , or a significant change in atomic density between the object and what is surrounding it, will usually scatter radar (radio) waves from its surface. This is particularly true for

text: electrically conductive

text: materials such as metal and carbon fibre, making radar well-suited to the detection of aircraft and ships.

text: Radar absorbing material

text: , containing

text: resistive

text: and sometimes

text: magnetic

text: substances, is used on military vehicles to

text: reduce radar reflection

text: . This is the radio equivalent of painting something a dark colour so that it cannot be seen by the eye at night.

text: The government also controls radio and television broadcasting. Radio broadcasts are in French, English, and indigenous languages; television is in French only. Some international broadcasts are available, but transmission of some programming has been disrupted by the government in the past. In 1998, there were 2 AM and 9 FM radio stations, with 14 television stations reported in 1999. In 2003, there were an estimated 185 radios and 61 television sets for every 1,000 people. The same year, there were 9.3 personal computers for every 1,000 people and 14 of every 1,000 people had access to the Internet. There were three secure Internet servers in the country in 2004.

text: The government also controls radio and television broadcasting. Radio broadcasts are in

text: French

text: English

text: , and indigenous languages; television is in French only. Some international broadcasts are available, but transmission of some programming has been disrupted by the government in the past. In 1998, there were 2 AM and 9 FM radio stations, with 14 television stations reported in 1999. In 2003, there were an estimated 185 radios and 61 television sets for every 1,000 people. The same year, there were 9.3 personal computers for every 1,000 people and 14 of every 1,000 people had access to the

text: Internet

text: . There were three secure Internet servers in the country in 2004.

text: The waveguide E band is the range of radio frequencies from 60 GHz to 90 GHz in the electromagnetic spectrum, corresponding to the recommended frequency band of operation of WR12 waveguides. These frequencies are equivalent to wave lengths between 5 mm and 3.333 mm. The E band is in the EHF range of the radio spectrum.

text: The

text: waveguide

text: E band is the range of

text: radio frequencies

text: from 60 GHz to 90 GHz in the

text: electromagnetic spectrum

text: , corresponding to the recommended frequency band of operation of

text: waveguides. These frequencies are equivalent to

text: wave length

text: s between 5 mm and 3.333 mm. The E band is in the

text: EHF

text: range of the

text: radio spectrum

text: Tagum, being in broadcast range from television and cable stations based in Davao City, has no indigenous media industry until 2005, when Manila Broadcasting Company started airing as Radyo Natin Tagum. Four radio stations started airing after the local media explosion in 2007. Another radio station, 100.7 Radio Caritas FM, started airing in the waves by January 2010. And in November 2014, the first Christian Contemporary radio and TV station, 93.5 Care Radio & Care tv9 (CARE TELERADIO), started airing purely Christian music.

text: Tagum, being in broadcast range from television and cable stations based in Davao City, has no indigenous media industry until 2005, when

text: Manila Broadcasting Company

text: started airing as Radyo Natin Tagum. Four radio stations started airing after the local media explosion in 2007. Another radio station, 100.7 Radio Caritas FM, started airing in the waves by January 2010. And in November 2014, the first Christian Contemporary radio and TV station, 93.5 Care Radio & Care tv9 (CARE TELERADIO), started airing purely Christian music.

text: Ocean surface waves are oscillations caused by the friction from air moving across the surface of the water. This friction transfers energy and forms surface waves in the water perpendicular to the direction of the wind. The top of a wave is known as its crest and its foot as its trough; the distance between two crests is the wavelength. These waves are mechanical: as they approach, the water molecules at a given point rise up and, as they pass, the water molecules go down, tracing a roughly circular path. The energy is passed across the surface and does not represent a horizontal motion of the water itself. The sea state of the ocean is determined by the size of these waves, which—on the open ocean—depends upon the wind speed and the fetch, the distance over which the wind blows upon the water. The smallest waves are called ripples. As strong and prolonged winds push against ripples' raised crests, larger and more irregular waves form, which known as seas. These waves reach their maximum height when the rate at which they are traveling nearly matches the speed of the wind and, over time, they naturally separate into long, powerful waves with a common direction and wavelength. These swells are particularly common in the Roaring Forties of the Southern Hemisphere where the wind blows continuously. When the wind dies down, ripples easily disappear owing to water's surface tension, but seas and swells are only slowly reduced by gravity and destructive interference from other waves. Constructive interference, however, can also cause individual rogue waves much higher than normal. Most waves are less than  high and it is not unusual for strong storms to double or triple that height; offshore construction such as wind farms and oil platforms use these measurements in computing the hundred-year wave they are designed against. Rogue waves, however, have been documented at heights above .

text: Ocean surface waves

text: are oscillations caused by the

text: friction

text: from

text: air

text: moving across the surface of the water. This friction transfers

text: energy

text: and forms

text: surface wave

text: s in the water perpendicular to the direction of the wind. The top of a wave is known as its

text: crest

text: and its foot as its

text: trough

text: ; the distance between two crests is the

text: wavelength

text: . These waves are

text: mechanical

text: : as they approach, the water molecules at a given point rise up and, as they pass, the water molecules go down, tracing a roughly circular path. The energy is passed across the surface and does not represent a horizontal motion of the water itself. The

text: sea state

text: of the ocean is determined by the size of these waves, which—on the

text: open ocean

text: —depends upon the

text: wind speed

text: and the

text: fetch

text: , the distance over which the wind blows upon the water. The smallest waves are called

text: ripples

text: . As strong and prolonged winds push against ripples' raised crests, larger and more irregular waves form, which known as

text: seas

text: . These waves reach their maximum height when the rate at which they are traveling nearly matches the speed of the wind and, over time, they naturally separate into long, powerful waves with a common direction and wavelength. These

text: swells

text: are particularly common in the

text: Roaring Forties

text: of the Southern Hemisphere where the wind blows continuously. When the wind dies down, ripples easily disappear owing to water's

text: surface tension

text: , but seas and swells are only slowly

text: reduced by gravity

text: and

text: destructive interference

text: from other waves.

text: Constructive interference

text: , however, can also cause individual

text: rogue wave

text: s much higher than normal. Most waves are less than  high and it is not unusual for strong storms to double or triple that height;

text: offshore construction

text: such as

text: wind farms

text: and

text: oil platform

text: s use these measurements in computing the

text: hundred-year wave

text: they are designed against. Rogue waves, however, have been documented at heights above .

text: The station signed on October 18, 1962 as a sister to now defunct 1140 AM WCLW located at 791 McPherson Street in Mansfield, Ohio and owned by Mansfield Broadcasting Inc owned by Frederick Eckardt. Simulcasting 100% of the AM station 105.3 aired a Mainstream Rock/Pop format that was a first in the area. In 1975, the company changed names to Greater Mansfield Broadcasting Inc. having Lynn Eckardt join as Vice President of the company. In 1983, WCLW-AM would become country competing against nearby WNCO Ashland, Ohio and WCLW-FM would change to a MOR format. Greater Mansfield Broadcasting would sell both WCLW-AM/FM to Cleveland lawyer and radio specialist Harrison Fuerst's Treasure Radio on April 16, 1987 for $2 Million. Fuerst also was purchasing WMAN-AM/Mansfield for $1.6 Million to combine with his 1490 WMGW and 100.3 WZPR Meadeville, Pennsylvania, 98.1 WJJR and now defunct 970 AM WHWB Rutland. Fuerst had owned other radio stations in Colorado Springs, Albany, Denver, Nebraska and Akron. The station changed its call letters to the current WYHT-FM on August 3, 1987.

text: The station signed on October 18, 1962 as a sister to now defunct 1140 AM WCLW located at 791 McPherson Street in

text: Mansfield, Ohio

text: and owned by Mansfield Broadcasting Inc owned by Frederick Eckardt. Simulcasting 100% of the AM station 105.3 aired a Mainstream Rock/Pop format that was a first in the area. In 1975, the company changed names to Greater Mansfield Broadcasting Inc. having Lynn Eckardt join as Vice President of the company. In 1983, WCLW-AM would become country competing against nearby WNCO

text: Ashland, Ohio

text: and WCLW-FM would change to a MOR format. Greater Mansfield Broadcasting would sell both WCLW-AM/FM to Cleveland lawyer and radio specialist Harrison Fuerst's Treasure Radio on April 16, 1987 for $2 Million. Fuerst also was purchasing

text: WMAN-AM

text: Mansfield

text: for $1.6 Million to combine with his 1490 WMGW and 100.3 WZPR

text: Meadeville, Pennsylvania

text: , 98.1 WJJR and now defunct 970 AM WHWB

text: Rutland

text: . Fuerst had owned other radio stations in

text: Colorado Springs

text: Albany

text: Denver

text: Nebraska

text: and

text: Akron

text: . The station changed its call letters to the current WYHT-FM on August 3, 1987.

text: Cable television is a system of broadcasting television programming to paying subscribers via radio frequency (RF) signals transmitted through coaxial cables or light pulses through fiber-optic cables. This contrasts with traditional terrestrial television, in which the television signal is transmitted over the air by radio waves and received by a television antenna attached to the television. In the 2000s, FM radio programming, high-speed Internet, telephone service, and similar non-television services may also be provided through these cables. The abbreviation CATV is often used for cable television. It originally stood for Community Access Television or Community Antenna Television, from cable television's origins in 1948: in areas where over-the-air reception was limited by distance from transmitters or mountainous terrain, large "community antennas" were constructed, and cable was run from them to individual homes. The origins of cable broadcasting are even older as radio programming was distributed by cable in some European cities as far back as 1924. Earlier cable television was analog, but since the 2000s all cable operators have switched to, or are in the process of switching to, digital cable television.

text: Ground Wave propagation is a method of radio frequency propagation that uses the area between the surface of the earth and the ionosphere for transmission. The ground wave can propagate a considerable distance over the earth's surface particularly in the low frequency and medium frequency portion of the radio spectrum. Ground wave radio propagation is used to provide relatively local radio communications coverage.

text: Ground Wave propagation is a method of radio frequency propagation that uses the area between the surface of the earth and the

text: ionosphere

text: for transmission. The ground wave can propagate a considerable distance over the earth's surface particularly in the

text: low frequency

text: and

text: medium frequency

text: portion of the radio spectrum. Ground wave radio propagation is used to provide relatively local radio communications coverage.

text: Besides expanding the regular chorus, O'Neill created the Sound Waves in 2008. The Sound Waves are a specialized group of singers. Within four years the group expanded from 9 to 15 singers. The Sound Waves have been asked to perform at the North Shore Music Theater, Boston University, and other local venues. The Sound Waves perform at almost all school holiday assemblies and have even been on local radio and television. The group often does charity events to raise money for various charity organizations such as HEART and sells CDs every year of their music.

text: XETAC-AM/XHTAC-FM is a radio station on 1000 AM and 91.5 FM in Tapachula, Chiapas. The station carries the Exa FM format from MVS Radio.

text: XETAC-AM/XHTAC-FM is a radio station on

text: 1000 AM

text: and

text: 91.5 FM

text: in

text: Tapachula, Chiapas

text: . The station carries the Exa FM format from

text: MVS Radio

text: The city is the base for two commercial radio companies; Radio Tay, which has two stations, Tay FM and Tay 2, and Wave 102. Dundee also has a base for BBC Scotland's radio service Radio Scotland. Due to its close proximity to the Central Belt, it is also possible in Dundee to receive Heart Scotland, Capital FM Scotland, Kingdom FM and Forth 1.

text: The city is the base for two commercial radio companies;

text: Radio Tay

text: , which has two stations,

text: Tay FM

text: and

text: Tay 2

text: , and

text: Wave 102

text: . Dundee also has a base for

text: BBC Scotland

text: 's radio service

text: Radio Scotland

text: . Due to its close proximity to the

text: Central Belt

text: , it is also possible in Dundee to receive

text: Heart Scotland

text: Capital FM Scotland

text: Kingdom FM

text: and

text: Forth 1

text: Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Like all other electromagnetic waves, they travel at the speed of light. Naturally occurring radio waves are made by lightning, or by astronomical objects. Artificially generated radio waves are used for fixed and mobile radio communication, broadcasting, radar and other navigation systems, satellite communication, computer networks and innumerable other applications. Different frequencies of radio waves have different propagation characteristics in the Earth's atmosphere; long waves may cover a part of the Earth very consistently, shorter waves can reflect off the ionosphere and travel around the world, and much shorter wavelengths bend or reflect very little and travel on a line of sight.

text: Because of its relatively low audio quality due to audio bandwidth limitations, and its susceptibility to atmospheric and electrical interference, AM broadcasting now attracts mainly talk radio and news programming, while music radio and public radio mostly shifted to FM broadcasting in the late 1970s in the developed countries. However, in the late 1960s and 1970s, top 40 rock and roll stations in the U.S. and Canada such as WABC and CHUM transmitted highly processed and extended audio to 11 kHz, successfully attracting huge audiences. In the UK during the 1980s, the national speech station, BBC Radio 4, had an FM location, whereas BBC Radio 1, a music station, was confined to AM broadcasts. Frequency response is typically 40 Hz–5 kHz with a 50 dB signal to noise (S/N) ratio.

text: Because of its relatively low audio quality due to audio bandwidth limitations, and its susceptibility to atmospheric and electrical interference, AM broadcasting now attracts mainly

text: talk radio

text: and

text: news

text: programming, while

text: music radio

text: and

text: public radio

text: mostly shifted to

text: FM broadcasting

text: in the late 1970s in the

text: developed countries

text: . However, in the late 1960s and 1970s, top 40 rock and roll stations in the U.S. and Canada such as

text: WABC

text: and

text: CHUM

text: transmitted highly processed and extended audio to 11 kHz, successfully attracting huge audiences. In the UK during the 1980s, the national speech station,

text: BBC Radio 4

text: , had an FM location, whereas

text: BBC Radio 1

text: , a music station, was confined to AM broadcasts.

text: Frequency response

text: is typically 40 Hz–5 kHz with a 50

text: dB

text: signal to noise (S/N) ratio

text: In the V band and E band spectrum, wireless systems can utilize the significantly larger allocated spectrum and channels to deliver multi-Gigabit data rates. This enables a simple, robust, and low cost modem and radio design. Thus, V-Band and E-Band, millimeter-wave wireless systems provide significant cost advantages over 6–38 GHz wireless systems – allowing scaling capacity to Gigabit capacities, without additional radio equipment and licensing fees

text: In the

text: V band

text: and E band spectrum, wireless systems can utilize the significantly larger allocated spectrum and channels to deliver multi-Gigabit data rates. This enables a simple, robust, and low cost modem and radio design. Thus, V-Band and E-Band, millimeter-wave wireless systems provide significant cost advantages over 6–38 GHz wireless systems – allowing scaling capacity to Gigabit capacities, without additional radio equipment and licensing fees

text: At lower frequencies in the MF, LF, and VLF bands, due to diffraction radio waves can bend over obstacles like hills, and travel beyond the horizon as surface waves which follow the contour of the Earth.  These are called ground waves.  AM broadcasting stations use ground waves to cover their listening areas.  As the frequency gets lower the attenuation with distance decreases, so very low frequency (VLF) and extremely low frequency (ELF) ground waves can be used to communicate worldwide.  VLF and ELF waves can penetrate significant distances through water and earth, and these frequencies are used for mine communication and military communication with submerged submarines.

text: At lower frequencies in the

text: MF

text: LF

text: , and

text: VLF

text: bands, due to

text: diffraction

text: radio waves can bend over obstacles like hills, and travel beyond the horizon as

text: surface wave

text: s which follow the contour of the Earth.  These are called

text: ground wave

text: s.

text: AM broadcasting

text: stations use ground waves to cover their listening areas.  As the frequency gets lower the attenuation with distance decreases, so

text: very low frequency

text: (VLF) and

text: extremely low frequency

text: (ELF) ground waves can be used to communicate worldwide.  VLF and ELF waves can penetrate significant distances through water and earth, and these frequencies are used for mine communication and military communication with submerged submarines.

text: FM radio on the new band had to begin from the ground floor. As a commercial venture it remained a little-used audio enthusiasts' medium until the 1960s. The more prosperous AM stations, or their owners, acquired FM licenses and often broadcast the same programming on the FM station as on the AM station ("simulcasting"). The FCC limited this practice in the 1960s. By the 1980s, since almost all new radios included both AM and FM tuners, FM became the dominant medium, especially in cities. Because of its greater range, AM remained more common in rural environments.

text: FM radio on the new band had to begin from the ground floor. As a commercial venture it remained a little-used audio enthusiasts' medium until the 1960s. The more prosperous AM stations, or their owners, acquired FM licenses and often broadcast the same programming on the FM station as on the AM station ("

text: simulcasting

text: "). The FCC limited this practice in the 1960s. By the 1980s, since almost all new radios included both AM and FM tuners, FM became the dominant medium, especially in cities. Because of its greater range, AM remained more common in rural environments.

text: Microwaves are widely used for point-to-point communications because their small wavelength allows conveniently-sized antennas to direct them in narrow beams, which can be pointed directly at the receiving antenna. This allows nearby microwave equipment to use the same frequencies without interfering with each other, as lower frequency radio waves do. Another advantage is that the high frequency of microwaves gives the microwave band a very large information-carrying capacity; the microwave band has a bandwidth 30 times that of all the rest of the radio spectrum below it.  A disadvantage is that microwaves are limited to line of sight propagation; they cannot pass around hills or mountains as lower frequency radio waves can.

text: Microwaves are widely used for

text: point-to-point

text: communications because their small

text: wavelength

text: allows conveniently-sized

text: antenna

text: s to direct them in narrow beams, which can be pointed directly at the receiving antenna. This allows nearby microwave equipment to use the same frequencies without interfering with each other, as lower frequency radio waves do. Another advantage is that the high frequency of microwaves gives the microwave band a very large information-carrying capacity; the microwave band has a

text: bandwidth

text: 30 times that of all the rest of the

text: radio spectrum

text: below it.  A disadvantage is that microwaves are limited to

text: line of sight

text: propagation; they cannot pass around hills or mountains as lower frequency radio waves can.

text: WTOP AM (which was now on 820 in Frederick) changed its calls to WTWT and switched to the Washington Post Radio simulcast on June 28, 2007. On September 20, 2007, the 1500/107.7/820 multicast changed format over to a general talk format as "Talk Radio 3WT" under the WWWT/WWWT-FM/WWWB call letters, which was cancelled on August 11, 2008. WWWT and WWWB took over the "Federal News Radio" format (and for the 1500 kHz facility, the WFED calls), while WWWT-FM went back to simulcasting WTOP-FM. The former WFED took over the WTOP callsign on the AM dial and became a simulcast of WTOP, with preemptions for sporting events. On June 13, 2009, the 1050 AM frequency changed to a separate news/talk format, operated by Air America Radio as WZAA. On January 26, 2010, following the shutdown of Air America Radio, WZAA returned to the WTOP simulcast. It took back the WTOP call letters on February 1, 2010.  WTOP AM left the simulcast on June 23, 2010, as Bonneville leased the station to United Media Group.  United Media changed the call letters to WBQH and flipped to Regional Mexican.

text: WTOP AM (which was now on 820 in Frederick) changed its calls to WTWT and switched to the Washington Post Radio simulcast on June 28, 2007. On September 20, 2007, the 1500/107.7/820 multicast changed format over to a general talk format as "Talk Radio 3WT" under the WWWT/WWWT-FM/WWWB call letters, which was cancelled on August 11, 2008. WWWT and WWWB took over the "Federal News Radio" format (and for the 1500 kHz facility, the

text: WFED

text: calls), while WWWT-FM went back to simulcasting WTOP-FM. The former WFED took over the WTOP callsign on the AM dial and became a simulcast of WTOP, with preemptions for sporting events. On June 13, 2009, the 1050 AM frequency changed to a separate

text: news/talk

text: format, operated by

text: Air America Radio

text: as

text: WZAA

text: . On January 26, 2010, following the shutdown of Air America Radio, WZAA returned to the WTOP simulcast. It took back the WTOP call letters on February 1, 2010.  WTOP AM left the simulcast on June 23, 2010, as Bonneville leased the station to

text: United Media Group

text: .  United Media changed the call letters to

text: WBQH

text: and flipped to

text: Regional Mexican

text: AM radio technology is simpler than frequency modulated (FM) radio, Digital Audio Broadcasting (DAB), satellite radio or HD (digital) radio. An AM receiver detects amplitude variations in the radio waves at a particular frequency. It then amplifies changes in the signal voltage to drive a loudspeaker or earphones. The earliest crystal radio receivers used a crystal diode detector with no amplification, and required no power source other than the radio signal itself.

text: AM radio technology is simpler than

text: frequency modulated (FM) radio

text: Digital Audio Broadcasting

text: (DAB),

text: satellite radio

text: or

text: HD (digital) radio

text: . An AM receiver detects amplitude variations in the

text: radio wave

text: s at a particular frequency. It then amplifies changes in the signal

text: voltage

text: to drive a

text: loudspeaker

text: or

text: earphone

text: s. The earliest

text: crystal radio receiver

text: s used a

text: crystal diode detector

text: with no amplification, and required no power source other than the radio signal itself.

text: The discovery in 1912 of the amplifying ability of the Audion vacuum tube, invented in 1906 by Lee De Forest, solved these problems.  The vacuum tube feedback oscillator, invented in 1912 by Edwin Armstrong and Alexander Meissner, was a cheap source of continuous waves and could be easily modulated to make an AM transmitter.  Modulation did not have to be done at the output but could be applied to the signal before the final amplifier tube, so the microphone or other audio source didn't have to handle high power.  Wartime research greatly advanced the art of AM modulation, and after the war the availability of cheap tubes sparked a great increase in the number of radio stations experimenting with AM transmission of news or music.  The vacuum tube was responsible for the rise of AM radio broadcasting around 1920, the first electronic mass entertainment medium.  Amplitude modulation was virtually the only type used for radio broadcasting until FM broadcasting began after World War 2.

text: The discovery in 1912 of the amplifying ability of the

text: Audion

text: vacuum tube

text: , invented in 1906 by

text: Lee De Forest

text: , solved these problems.  The vacuum tube

text: feedback oscillator

text: , invented in 1912 by

text: Edwin Armstrong

text: and

text: Alexander Meissner

text: , was a cheap source of

text: continuous wave

text: s and could be easily

text: modulated

text: to make an AM transmitter.  Modulation did not have to be done at the output but could be applied to the signal before the final amplifier tube, so the microphone or other audio source didn't have to handle high power.  Wartime research greatly advanced the art of AM modulation, and after the war the availability of cheap tubes sparked a great increase in the number of radio stations experimenting with AM transmission of news or music.  The vacuum tube was responsible for the rise of

text: AM radio broadcasting

text: around 1920, the first electronic

text: mass entertainment

text: medium.  Amplitude modulation was virtually the only type used for

text: radio broadcasting

text: until

text: FM broadcasting

text: began after World War 2.

text: A continuous wave or continuous waveform (CW) is an electromagnetic wave of constant amplitude and frequency; a sine wave. In mathematical analysis, it is considered to be of infinite duration. Continuous wave is also the name given to an early method of radio transmission, in which a sinusoidal carrier wave is switched on and off. Information is carried in the varying duration of the on and off periods of the signal, for example by Morse code in early radio.  In early wireless telegraphy radio transmission, CW waves were also known as "undamped waves", to distinguish this method from damped wave transmission as effected by early spark gap style transmitters.

text: A continuous wave or continuous waveform (CW) is an

text: electromagnetic wave

text: of constant

text: amplitude

text: and

text: frequency

text: ; a

text: sine wave

text: . In

text: mathematical analysis

text: , it is considered to be of infinite duration. Continuous wave is also the name given to an early method of

text: radio

text: transmission

text: , in which a sinusoidal

text: carrier wave

text: is switched on and off.

text: Information

text: is carried in the varying duration of the

text: on and off periods

text: of the signal, for example by

text: Morse code

text: in early radio.  In early

text: wireless telegraphy

text: radio transmission, CW waves were also known as "undamped waves", to distinguish this method from

text: damped wave

text: transmission as effected by early spark gap style transmitters.

text: Changing magnetic dipole fields (i.e., magnetic near-fields) are used commercially for many types of magnetic induction devices. These include motors and electrical transformers at low frequencies, and devices such as metal detectors and MRI scanner coils at higher frequencies. Sometimes these high-frequency magnetic fields change at radio frequencies without being far-field waves and thus radio waves; see RFID tags.See also near-field communication.Further uses of near-field EM effects commercially, may be found in the article on virtual photons, since at the quantum level, these fields are represented by these particles. Far-field effects (EMR) in the quantum picture of radiation, are represented by ordinary photons.

text: Changing magnetic dipole fields (i.e., magnetic near-fields) are used commercially for many types of

text: magnetic induction

text: devices. These include motors and electrical transformers at low frequencies, and devices such as

text: metal detector

text: s and

text: MRI

text: scanner coils at higher frequencies. Sometimes these high-frequency magnetic fields change at radio frequencies without being far-field waves and thus radio waves; see

text: RFID

text: tags.See also

text: near-field communication

text: .Further uses of near-field EM effects commercially, may be found in the article on

text: virtual photon

text: s, since at the quantum level, these fields are represented by these particles. Far-field effects (EMR) in the quantum picture of radiation, are represented by ordinary

text: photon

text: s.

text: , that the radio wave illuminates uniformly:

text: , that the radio wave

text: illuminates

text: uniformly:

text: The National Capital Radio & Television Museum contains educational resources and displays to increase public awareness on the impact of electronic media. The museum's collection contains a history of the development of pre-radio technology and progresses into television and other modern radio-based technology. The museum also includes interactive demonstrations of how radio waves work, early recordings of radio and television programs, and exhibits appealing to children.  Visitor hours are Fridays 10 AM to 5 PM, Saturdays and Sundays 1 PM to 5 PM. Groups and school tours are arranged by prior appointment. Admission is free, although donations are welcomed.

text: At medium wave and shortwave frequencies (MF and HF bands) radio waves can reflect or refract from a layer of charged particles (ions) high in the atmosphere, called the ionosphere.  So radio waves transmitted at an angle into the sky can be reflected back to Earth beyond the horizon, at great distances, even transcontinental distances.  This is called skywave or "skip" propagation.  It is used by amateur radio operators to talk to other countries, for diplomatic communications, and shortwave broadcasting stations that broadcast internationally.  Skywave communication is variable, dependent on conditions in the upper atmosphere, and can be disrupted by events like solar flares, it is most reliable at night and in the winter.  Due to its unreliability, since the advent of communication satellites in the 1960s many long range communication needs that previously used skywaves now use satellites.

text: At

text: medium wave

text: and

text: shortwave

text: frequencies (

text: MF

text: and

text: HF

text: bands) radio waves can reflect or refract from a layer of

text: charged particle

text: s (

text: ion

text: s) high in the atmosphere, called the

text: ionosphere

text: .  So radio waves transmitted at an angle into the sky can be reflected back to Earth beyond the horizon, at great distances, even transcontinental distances.  This is called

text: skywave

text: or "skip" propagation.  It is used by

text: amateur radio

text: operators to talk to other countries, for

text: diplomatic communications

text: , and shortwave broadcasting stations that broadcast internationally.  Skywave communication is variable, dependent on conditions in the upper atmosphere, and can be disrupted by events like

text: solar flare

text: s, it is most reliable at night and in the winter.  Due to its unreliability, since the advent of

text: communication satellite

text: s in the 1960s many long range communication needs that previously used skywaves now use satellites.

text: Whip antennas are normally designed as resonant antennas; the rod acts as a resonator for radio waves, with standing waves of voltage and current reflected back and forth from its ends. Therefore, the length of the antenna rod is determined by the wavelength of the radio waves used. The most common length is approximately one-quarter of the wavelength, called a "quarter-wave whip" (although  often shortened by the use of a loading coil; see Electrically short whips below). For example, the common quarter-wave whip antennas used on FM radios in the USA are approximately 75 cm long, which is roughly one-quarter the length of radio waves in the FM radio band, which are 2.78 to 3.41 meters long. Half-wave antennas are also common.

text: Whip antennas are normally designed as

text: resonant

text: antennas; the rod acts as a

text: resonator

text: for radio waves, with

text: standing wave

text: s of voltage and current reflected back and forth from its ends. Therefore, the length of the antenna rod is determined by the

text: wavelength

text: of the radio waves used. The most common length is approximately one-quarter of the wavelength, called a "quarter-wave whip" (although  often shortened by the use of a

text: loading coil

text: ; see

text: Electrically short whips

text: below). For example, the common quarter-wave whip antennas used on FM radios in the USA are approximately 75 cm long, which is roughly one-quarter the length of radio waves in the

text: FM radio

text: band, which are 2.78 to 3.41 meters long.

text: Half-wave antenna

text: s are also common.

text: XHTL-FM/XETL-AM is a combo radio station in Tuxpan, Veracruz. Broadcasting on 91.5 FM and 1390 AM, XHTL/XETL is known as Radio Ola.

text: XHTL-FM/XETL-AM is a combo radio station in

text: Tuxpan, Veracruz

text: . Broadcasting on 91.5 FM and 1390 AM, XHTL/XETL is known as Radio Ola.

text: Brown sold his interest in WTWA to Kobak in 1950. In 1953, Kobak bought the local "McDuffie Progress" newspaper, combined it with the radio station and promoted Frank Hash, the editor of the newspaper, to be WTWA's manager. Hash then bought the newspaper and radio station in 1957. In 1962, Gene Harden, WTWA's longtime manager, bought the station from Hash. In an unusual turn of events, Harden sold WTWA to its founder, Walter Brown in 1977. Brown, by then longtime owner of WSPA-AM/FM/TV in Spartanburg, had returned to radio ownership in Thomson, building WTHO-AM/FM in 1972. WTHO-AM was a daytime-only station at 1530 on the dial, inferior to WTWA's 1,000 full-time facility at 1240. Upon his purchase of WTWA, Brown sent the 1530 license to the FCC for cancellation

text: Radio broadcasting is a unidirectional wireless transmission over radio waves intended to reach a wide audience. Stations can be linked in radio networks to broadcast a common radio format, either in broadcast syndication or simulcast or both. Audio broadcasting also can be done via cable radio, local wire television networks, satellite radio, and internet radio via streaming media on the Internet. The signal types can be either analog audio or digital audio.

text: Radio broadcasting is a unidirectional

text: wireless

text: transmission over

text: radio waves

text: intended to reach a wide

text: audience

text: . Stations can be linked in

text: radio network

text: s to broadcast a common

text: radio format

text: , either in

text: broadcast syndication

text: or

text: simulcast

text: or both. Audio broadcasting also can be done via

text: cable radio

text: , local wire

text: television network

text: s,

text: satellite radio

text: , and

text: internet radio

text: via

text: streaming media

text: on the

text: Internet

text: . The signal types can be either

text: analog audio

text: or

text: digital audio

text: In 1944, NBC television introduced its first official logo, a microphone surrounded by lightning bolts, which was a modification of the original 1926 logo used by the NBC radio network. Lightning bolts were also part of the logo of corporate parent RCA, as well as that of one-time sister company RKO Pictures. The waves placed on the left side were meant for the radio network, and the right waves were meant for the television network. A network identification featuring this logo includes the voiceover, "This is NBC, the National Broadcasting Company", followed by the NBC chimes. On the network's flagship television station WNBT (now WNBC), this was accompanied by the voiceover, "WNBT, New York". At the beginning of telecasts, a card was shown with an unusual NBC logo with the letters in cursive and enclosed in a rectangle (a logo also used at the end of broadcasts in the early 1950s). This was replaced by another card depicting an NBC cameraman operating an RCA camera was shown underneath the text "NBC Television Presents". The letters "NBC" lighting in tune with the chimes indicated time for station identification or the end of a telecast.

text: In 1944, NBC television introduced its first official logo, a microphone surrounded by lightning bolts, which was a modification of the original 1926 logo used by the NBC radio network. Lightning bolts were also part of the logo of corporate parent

text: RCA

text: , as well as that of one-time sister company

text: RKO Pictures

text: . The waves placed on the left side were meant for the radio network, and the right waves were meant for the television network. A network identification featuring this logo includes the voiceover, "This is NBC, the National Broadcasting Company", followed by the

text: NBC chimes

text: . On the network's

text: flagship television station

text: WNBT (now

text: WNBC

text: ), this was accompanied by the voiceover, "WNBT, New York". At the beginning of telecasts, a card was shown with an unusual NBC logo with the letters in cursive and enclosed in a rectangle (a logo also used at the end of broadcasts in the early 1950s). This was replaced by another card depicting an NBC cameraman operating an RCA camera was shown underneath the text "NBC Television Presents". The letters "NBC" lighting in tune with the chimes indicated time for station identification or the end of a telecast.

text: Terrestrial television was the first technology used for television broadcasting, with the first long-distance public television broadcast from Washington, D.C., on 7 April 1927. The BBC began broadcasting in 1929, and had a regular schedule of television programmes in 1930.  However these early experimental systems had insufficient picture quality to attract the public, due to their mechanical scan technology, and television didn't become widespread until after World War II with the advent of electronic scan technology.  The television broadcasting business followed the model of radio networks, with local television stations in cities and towns affiliated with television networks, either commercial (in USA) or government-controlled (in Europe), which provided content.  Television broadcasts were in black and white until the 1960s, when color television broadcasting began.

text: Terrestrial television was the first technology used for television broadcasting, with the first long-distance

text: public television

text: broadcast from Washington, D.C., on 7 April 1927. The

text: BBC

text: began broadcasting in 1929, and had a regular schedule of

text: television program

text: mes in 1930.  However these early experimental systems had insufficient picture quality to attract the public, due to their

text: mechanical scan

text: technology, and television didn't become widespread until after

text: World War II

text: with the advent of

text: electronic scan

text: technology.  The television broadcasting business followed the model of

text: radio network

text: s, with local television stations in cities and towns affiliated with

text: television network

text: s, either commercial (in USA) or government-controlled (in Europe), which provided content.  Television broadcasts were in

text: black and white

text: until the 1960s, when

text: color television

text: broadcasting began.

text: Raechel Donahue is a rock radio pioneer generally associated with her husband Tom Donahue, who died in 1975. She was the original entertainment reporter for CNN, briefly served as VJ for Cable Music Channel and a longtime radio personality in San Francisco on KSAN and in Los Angeles on KMET, KROQ-FM, KIIS-FM, and in 2006 was heard on SIRIUS Satellite Radio (SIRIUS), Classic Vinyl and Sirus Gold.  In 2009 she had a daily audio blog on the All Star Radio Network called Brush With Fame and a weekend show on the Dial-Global Radio Network.  Author, journalist and voiceover artist for film, television and commercials, she is featured in the Rock and Roll Hall of Fame main hall and in The Paley Center for Media. She was honored by the latter in both the New York and Los Angeles exhibitions entitled She Made It: Women Creating Television and Radio. She is also a major figure (along with husband Tom) in Jim Ladd's semi-biographical account of the history of KMET, "Radio Waves: Life and Revolution on the FM Dial". Currently, Raechel works as a documentary film maker; "Airplay", was released in the summer of 2007 and "Drawn to Yellowstone" was by Wyoming PBS in 2009 and the self-produced documentary about World War II Japanese internment camps, "Heart Mountain: An All American Town," was played on public television stations across America and in 175 countries and territories by the Armed Forces Network. Donahue has written hundreds of articles about travel and food for USAToday.com, eHow, AZCentral and other publications. Since 2012, Raechel has hosted the weekend show on internet radio station Boss Boss Radio, playing Top 40 hits from the Boss Radio era 1964 thru 1980.

text: Raechel Donahue is a rock radio pioneer generally associated with her husband

text: Tom Donahue

text: , who died in 1975. She was the original entertainment reporter for

text: CNN

text: , briefly served as VJ for

text: Cable Music Channel

text: and a longtime radio personality in

text: San Francisco

text: on

text: KSAN

text: and in

text: Los Angeles

text: on

text: KMET

text: KROQ-FM

text: KIIS-FM

text: , and in 2006 was heard on

text: SIRIUS Satellite Radio

text: (SIRIUS),

text: Classic Vinyl

text: and

text: Sirus Gold

text: .  In 2009 she had a daily audio blog on the All Star Radio Network called Brush With Fame and a weekend show on the Dial-Global Radio Network.  Author, journalist and voiceover artist for film, television and commercials, she is featured in the

text: Rock and Roll Hall of Fame

text: main hall and in

text: The Paley Center for Media

text: . She was honored by the latter in both the New York and Los Angeles exhibitions entitled She Made It: Women Creating Television and Radio. She is also a major figure (along with husband Tom) in

text: Jim Ladd

text: 's semi-biographical account of the history of

text: KMET

text: , "Radio Waves: Life and Revolution on the FM Dial". Currently, Raechel works as a documentary film maker; "Airplay", was released in the summer of 2007 and "Drawn to Yellowstone" was by Wyoming PBS in 2009 and the self-produced documentary about World War II Japanese internment camps, "Heart Mountain: An All American Town," was played on public television stations across America and in 175 countries and territories by the Armed Forces Network. Donahue has written hundreds of articles about travel and food for USAToday.com, eHow, AZCentral and other publications. Since 2012, Raechel has hosted the weekend show on internet radio station Boss Boss Radio, playing Top 40 hits from the Boss Radio era 1964 thru 1980.

text: BBC Radio Devon broadcasts to Exeter locally on FM (95.8) and AM (990 AM/MW), although the majority of programming comes from Plymouth. In the evenings, BBC Radio Devon joins the South West Regional service. Heart South West, formerly Gemini FM and Devonair, covers the city on 97.0 FM, with East Devon and Torbay using their own frequencies. Both Heart and BBC Devon broadcast from the St. Thomas transmitter, which also provides the city with television coverage; AM radio is broadcast from Pearce's Hill next to J31 of the M5. Other radio stations include Exeter FM, an easy listening station broadcasting on 107.3 FM, Phonic.FM which provides a "no adverts no playlist" alternative on 106.8 FM or online at www.phonic.fm, VI, a station broadcasting from the West of England School and College on 1386 AM/MW. The University has a well established student station, Xpression FM, which broadcasts on 87.7 FM using two low-powered transmitters, although it can be heard over much of the north of the city.

text: BBC Radio Devon

text: broadcasts to Exeter locally on FM (95.8) and AM (990 AM/MW), although the majority of programming comes from Plymouth. In the evenings, BBC Radio Devon joins the South West Regional service.

text: Heart South West

text: , formerly

entity_section: Former commercial radio stations in Exeter and Torbay

text: Gemini FM

text: and

text: Devonair

text: , covers the city on 97.0 FM, with

text: East Devon

text: and

text: Torbay

text: using their own frequencies. Both Heart and BBC Devon broadcast from the St. Thomas transmitter, which also provides the city with television coverage; AM radio is broadcast from Pearce's Hill next to J31 of the M5. Other radio stations include

text: Exeter FM

text: , an easy listening station broadcasting on 107.3 FM, Phonic.FM which provides a "no adverts no playlist" alternative on 106.8 FM or online at www.phonic.fm, VI, a station broadcasting from the West of England School and College on 1386 AM/MW. The University has a well established student station,

text: Xpression FM

text: , which broadcasts on 87.7 FM using two low-powered transmitters, although it can be heard over much of the north of the city.

text: Dead air is defined as "a period of silence especially during a radio broadcast," which has been extended, in some formal definitions, to include both audio and video signals (and so to this extent, to television as well as radio broadcasts). Hence, generalizing, the term can be understood to refer to any unintended period of silence interrupting any media broadcast, during which no signal, audio or video, is transmitted. Technically, the absence of sound in a radio transmission implies that only an unmodulated carrier wave is being transmitted, for modes that send one, or absence of the transmitting signal altogether for modes that do not.

text: Dead air is defined as "a period of silence especially during a radio broadcast," which has been extended, in some formal definitions, to include both audio and video signals (and so to this extent, to television as well as radio broadcasts). Hence, generalizing, the term can be understood to refer to any unintended period of silence interrupting any media broadcast, during which no signal, audio or video, is transmitted. Technically, the absence of sound in a radio transmission implies that only an unmodulated

text: carrier wave

text: is being transmitted, for

text: modes

text: that send one, or absence of the transmitting signal altogether for modes that do not.

text: and a wave direction spectrum

text: and a wave direction spectrum

text: Radio stations are on AM, FM and DAB+ frequencies. ABC stations include News Radio (585AM), 720 ABC Perth, Radio National (810AM), Classic FM (97.7FM) and Triple J (99.3FM). The six local commercial stations are: 92.9, Nova 93.7, Mix 94.5, 96fm, on FM and 882 6PR and 1080 6IX on AM. DAB+ has mostly the same as both FM and AM plus national stations from the ABC/SBS, Radar Radio and Novanation, along with local stations My Perth Digital and HotCountry Perth. Major community radio stations include RTRFM (92.1FM), Sonshine FM (98.5FM), SportFM (91.3FM) and Curtin FM (100.1FM).

text: Radio stations are on AM, FM and DAB+ frequencies. ABC stations include

text: News Radio

text: 720 ABC Perth

text: Radio National

text: Classic FM

text: (97.7FM) and

text: Triple J

text: (99.3FM). The six local commercial stations are:

text: Nova 93.7

text: Mix 94.5

text: , on FM and

text: 882 6PR

text: and

text: 1080 6IX

text: on AM. DAB+ has mostly the same as both FM and AM plus national stations from the ABC/SBS, Radar Radio and Novanation, along with local stations My Perth Digital and HotCountry Perth. Major community radio stations include

text: RTRFM

text: (92.1FM), Sonshine FM (98.5FM), SportFM (91.3FM) and Curtin FM (100.1FM).

text: Some energy is also lost from the system as a whole and from the arc as a broad spectrum of electromagnetic radiation, in the form of radio waves and light. These radio waves can cause undesirable clicks and pops on nearby radio receivers.

text: In 1995, with the addition of Radio 98.9 FM, catering largely to the urban youth, the National Broadcasting Service (i.e. the radio frequencies)  were relocated to the TTT compound at 11A Maraval Road in POS. Yet a further frequency came on board shortly thereafter - 91.1 FM. This frequency was for a while also used to rebroadcast NBS Radio 610 AM as an FM signal. Under the rebranded International Communications Network (ICN), 91.1 FM eventually changed its format entirely to East Indian programming in 1998. Radio 610 continued to broadcast on the AM dial, but progressively lost its traditional listening audience due to a weakening of the quality of its broadcast signal and a reduction in allocated financial resources to upgrade its equipment and programming.

text:
(current format as WBZ-FM)|share              = |share as of        = |share source       = |format             = Sports radio
HD2: WBCN
HD3: WBZ simulcast|language           = |power              = |erp                = 9,000 watts|haat               = 349 meters|class              = B|facility_id        = 1901|coordinates        = |callsign_meaning   = from heritage sister station WBZ (AM)|former_callsigns   = WNAC-FM (1948–1958)
WRKO-FM (1958–1968)
WROR (1968–1991)
WBMX(-FM) (1991–2009)|former_frequencies = |affiliations       = CBS Sports Radio
New England Patriots Radio Network
Boston Bruins Radio Network
Boston Celtics Radio Network|owner              = CBS Radio|licensee           = CBS Radio Stations Inc.|sister_stations    = WBMX, WBZ, WBZ-TV, WODS, WSBK-TV, WZLX|webcast            = Listen Live
HD2: Listen Live|website            =

text: (current format as WBZ-FM)|share              = |share as of        = |share source       = |format             =

text: Sports radio

text: WBCN

text: WBZ

text: simulcast|language           = |power              = |erp                = 9,000

text: watt

text: s|haat               = 349 meters|class              = B|facility_id        = 1901|coordinates        = |callsign_meaning   = from heritage sister station

text: WBZ (AM)

text:
|former_callsigns   = WNAC-FM (1948–1958)
WRKO-FM (1958–1968)
WROR (1968–1991)

text: WBMX(-FM)

text: (1991–2009)|former_frequencies = |affiliations       =

text: CBS Sports Radio

text: <br>

text: New England Patriots Radio Network

text: <br>

text: Boston Bruins Radio Network

text: <br>

text: Boston Celtics Radio Network

text: |owner              =

text: CBS Radio

text: |licensee           = CBS Radio Stations Inc.|sister_stations    =

text: WBMX

text: WBZ

text: WBZ-TV

text: WODS

text: WSBK-TV

text: WZLX

text: |webcast            = Listen Live<br>HD2: Listen Live|website            =

text: In Asia, television has traditionally been state-controlled, although the number of private stations is increasing, as is competition from satellite and cable television. Japan's NHK is a non-commercial network similar to the BBC, funded by a television license fee, and has more editorial independence over news and current affairs than broadcasters like India's state-run Doordarshan or China's China Central Television (CCTV). In Malaysia, television was dominated by Radio Televisyen Malaysia (RTM), a government-owned agency, from 1963 until 1984. From 1984, however, private television stations started emerging, with TV3 being the only private broadcaster for ten years until the introduction of MetroVision, which was operated between 1995 and 1999. As of December 2013, there are 5 private stations and 3 government-owned ones in the country. Even though TV Alhijrah and WBC has begun broadcasting in recent years, RTM and Media Prima still controls most of the free-to-air television market. Free-to-air television in Singapore is currently monopolised by MediaCorp, with 8 channels broadcast there.

text: In

text: Asia

text: , television has traditionally been state-controlled, although the number of private stations is increasing, as is competition from

text: satellite

text: and

text: cable television

text: Japan

text: 's

text: NHK

text: is a non-commercial network similar to the

text: BBC

text: , funded by a

text: television license

text: fee, and has more

text: editorial independence

text: over news and current affairs than broadcasters like

text: India

text: 's state-run

text: Doordarshan

text: or

text: China's

text: China Central Television

text: (CCTV). In

text: Malaysia

text: , television was dominated by

text: Radio Televisyen Malaysia

text: (RTM), a government-owned agency, from 1963 until 1984. From 1984, however, private television stations started emerging, with

text: being the only private broadcaster for ten years until the introduction of

text: MetroVision

text: , which was operated between 1995 and 1999. As of December 2013, there are 5 private stations and 3 government-owned ones in the country. Even though

text: TV Alhijrah

text: and

text: WBC

text: has begun broadcasting in recent years, RTM and Media Prima still controls most of the free-to-air television market.

text: Free-to-air

text: television in

text: Singapore

text: is currently monopolised by

text: MediaCorp

text: , with 8 channels broadcast there.

text: At most wavelengths, however, the information carried by electromagnetic radiation is not directly detected by human senses. Natural sources produce EM radiation across the spectrum, and technology can also manipulate a broad range of wavelengths. Optical fiber transmits light that, although not necessarily in the visible part of the spectrum (it is usually infrared), can carry information. The modulation is similar to that used with radio waves.

text: At most wavelengths, however, the information carried by electromagnetic radiation is not directly detected by human senses. Natural sources produce EM radiation across the spectrum, and technology can also manipulate a broad range of wavelengths.

text: Optical fiber

text: transmits light that, although not necessarily in the visible part of the spectrum (it is usually infrared), can carry information. The modulation is similar to that used with radio waves.

text: In radio and electronics, an antenna (plural antennae or antennas), or aerial, is an electrical device which converts electric power into radio waves, and vice versa.  It is usually used with a radio transmitter or radio receiver.  In transmission, a radio transmitter supplies an electric current oscillating at radio frequency  (i.e. a high frequency alternating current (AC)) to the antenna's terminals, and the antenna radiates the energy from the current as electromagnetic waves (radio waves). In reception, an antenna intercepts some of the power of an electromagnetic wave in order to produce a tiny voltage at its terminals, that is applied to a receiver to be amplified.

text: In

text: radio

text: and

text: electronics

text: , an antenna (plural antennae or antennas), or aerial, is an electrical device which converts

text: electric power

text: into

text: radio wave

text: s, and vice versa.  It is usually used with a

text: radio transmitter

text: or

text: radio receiver

text: .  In

text: transmission

text: , a radio transmitter supplies an electric current oscillating at

text: radio frequency

text: (i.e. a high frequency

text: alternating current

text: (AC)) to the antenna's terminals, and the antenna radiates the energy from the current as

text: electromagnetic wave

text: s (radio waves). In

text: reception

text: , an antenna intercepts some of the power of an electromagnetic wave in order to produce a tiny voltage at its terminals, that is applied to a receiver to be

text: amplified

text: Stephen Hill's found the new-age radio show Hearts of Space in 1973. In 1983, was picked up by NPR for syndication to 230 affiliates nationally, and year later was started a record label Hearts of Space Records. On Valentine's Day in 1987, the former Los Angeles rock radio station KMET changed to a full-time New-age music format with new call letters KTWV, branded as The Wave. During The Wave's new-age period, management told the station employees to refer to The Wave as a "mood service" rather than a "radio station". DJs stopped announcing the titles of the songs, and instead, to maintain an uninterrupted mood, listeners could call a 1-800 phone number to find out what song was playing. News breaks were also re-branded and referred to as "wave breaks". Other New-age-specialty radio programs included Forest's Musical Starstreams and John Diliberto's Echoes. Most major cable television networks have channels that play music without visuals, including channels for New age, such as the "Soundscapes" channel on Music Choice. The two satellite radio companies Sirius Satellite Radio & XM Satellite Radio each had their own channels that played new-age music. Sirius—Spa (Sirius XM) (73), XM—Audio Visions (77). When the two merged in November 2008 and became SiriusXM, the Spa name was retained for the music channel with the majority of Audio Vision’s music library being used.

text: Stephen Hill

text: 's found the new-age radio show

text: Hearts of Space

text: in 1973. In 1983, was picked up by

text: NPR

text: for syndication to 230 affiliates nationally, and year later was started a record label

text: Hearts of Space Records

text: . On Valentine's Day in 1987, the former Los Angeles rock radio station KMET changed to a full-time New-age music format with new call letters

text: KTWV

text: , branded as The Wave. During The Wave's new-age period, management told the station employees to refer to The Wave as a "mood service" rather than a "radio station". DJs stopped announcing the titles of the songs, and instead, to maintain an uninterrupted mood, listeners could call a 1-800 phone number to find out what song was playing. News breaks were also re-branded and referred to as "wave breaks". Other New-age-specialty radio programs included Forest's

text: Musical Starstreams

text: and John Diliberto's

text: Echoes

text: . Most major

text: cable television

text: networks have channels that play music without visuals, including channels for New age, such as the "Soundscapes" channel on

text: Music Choice

text: . The two satellite radio companies

text: Sirius Satellite Radio

text: XM Satellite Radio

text: each had their own channels that played new-age music. Sirius—

text: Spa (Sirius XM)

text: (73), XM—

text: Audio Visions

text: (77). When the two merged in November 2008 and became

text: SiriusXM

text: , the Spa name was retained for the music channel with the majority of Audio Vision’s music library being used.

text: The meaning and usage of the word "radio" has developed in parallel with developments within the field of communications and can be seen to have three distinct phases: electromagnetic waves and experimentation; wireless communication and technical development; and radio broadcasting and commercialization. In an 1864 presentation, published in 1865, James Clerk Maxwell proposed his theories and mathematical proofs on electromagnetism that showed that light and other phenomenon were all types of electromagnetic waves propagating through free space. In 1886–88 Heinrich Rudolf Hertz conducted a series of experiments that proved the existence of Maxwell's electromagnetic waves, using a frequency in what would later be called the radio spectrum. Many individuals—inventors, engineers, developers and businessmen—constructed systems based on their own understanding of these and other phenomenon, some predating Maxwell and Hertz's discoveries. Thus "wireless telegraphy" and radio wave-based systems can be attributed to multiple "inventors". Development from a laboratory demonstration to a commercial entity spanned several decades and required the efforts of many practitioners.

text: The meaning and usage of the word "radio" has developed in parallel with developments within the field of communications and can be seen to have three distinct phases: electromagnetic waves and experimentation; wireless communication and technical development; and radio broadcasting and commercialization. In an 1864 presentation, published in 1865,

text: James Clerk Maxwell

text: proposed his theories and mathematical proofs on

text: electromagnetism

text: that showed that light and other phenomenon were all types of electromagnetic waves propagating through

text: free space

text: . In 1886–88

text: Heinrich Rudolf Hertz

text: conducted a series of experiments that proved the existence of Maxwell's electromagnetic waves, using a frequency in what would later be called the

text: radio spectrum

text: . Many individuals—inventors, engineers, developers and businessmen—constructed systems based on their own understanding of these and other phenomenon, some predating Maxwell and Hertz's discoveries. Thus "wireless telegraphy" and radio wave-based systems can be attributed to multiple "inventors". Development from a laboratory demonstration to a commercial entity spanned several decades and required the efforts of many practitioners.

text: Because of their potential to cause interference and their resulting wasteful use of radio spectrum resources, there is an international prohibition against the use of class B damped wave radio emissions, established by the International Telecommunications Union in 1938.  However the definition of "damped waves" in these regulations is unclear when applied to modern technology, and recently there have been moves to amend this prohibition to exempt emerging radio technologies such as ultra-wideband transmission systems.

text: Because of their potential to cause interference and their resulting wasteful use of

text: radio spectrum

text: resources, there is an international prohibition against the use of class B damped wave radio emissions, established by the

text: International Telecommunications Union

text: in 1938.  However the definition of "damped waves" in these regulations is unclear when applied to modern technology, and recently there have been moves to amend this prohibition to exempt emerging radio technologies such as

text: ultra-wideband transmission systems

text: In 1998, Bose introduced the Wave Radio/CD, essentially Wave Radio with a CD player. The end of the waveguides were tapered by 2%.

text: Kana had made some appearances for Pro Wrestling Wave in 2008, but did not start working regularly for the promotion until the end of 2010, when NEO Japan Ladies Pro Wrestling folded. On July 24, 2011, Kana defeated Ayumi Kurihara in the finals to win the 2011 Catch the Wave tournament. On October 30, Kana and Kurihara defeated Ran Yu-Yu and Toshie Uematsu to win the Dual Shock Wave 2011 tournament and become the first ever Wave Tag Team Champions. While a tag team champion with Kurihara, Kana also regularly teamed with Mio Shirai as Triple Tails.S and on February 1, 2012, Kurihara, Mika Iida and Shuu Shibutani were made official members of Triple Tails. Four days later, Kana and Kurihara lost the Wave Tag Team Championship to Ran Yu-Yu and Toshie Uematsu. On March 6, the new incarnation of Triple Tails was named White Tails, in reference to Wave's top villainous alliance, Black Dahlia. On November 27, Kana defeated Yumi Ohka in a singles match, after which she declared herself the new "ace" of Wave. On February 17, Kana, as the 2011 Catch the Wave winner, was granted entrance into the Wave Single Championship tournament, defeating Mio Shirai in her semifinal match. On March 17, Kana was defeated in the finals of the tournament by Yumi Ohka.

text: Kana had made some appearances for Pro Wrestling Wave in 2008, but did not start working regularly for the promotion until the end of 2010, when NEO Japan Ladies Pro Wrestling folded. On July 24, 2011, Kana defeated Ayumi Kurihara in the finals to win the

text: 2011 Catch the Wave

text: tournament. On October 30, Kana and Kurihara defeated

text: Ran Yu-Yu

text: and

text: Toshie Uematsu

text: to win the

text: Dual Shock Wave 2011

text: tournament and become the first ever

text: Wave Tag Team Champions

text: . While a tag team champion with Kurihara, Kana also regularly teamed with

text: Mio Shirai

text: as Triple Tails.S and on February 1, 2012, Kurihara, Mika Iida and

text: Shuu Shibutani

text: were made official members of Triple Tails. Four days later, Kana and Kurihara lost the Wave Tag Team Championship to Ran Yu-Yu and Toshie Uematsu. On March 6, the new incarnation of Triple Tails was named White Tails, in reference to Wave's top

text: villainous

text: alliance, Black Dahlia. On November 27, Kana defeated

text: Yumi Ohka

text: in a singles match, after which she declared herself the new "

entity_name: Glossary of professional wrestling terms

text: ace

text: " of Wave. On February 17, Kana, as the 2011 Catch the Wave winner, was granted entrance into the

text: Wave Single Championship

text: tournament

text: , defeating Mio Shirai in her semifinal match. On March 17, Kana was defeated in the finals of the tournament by Yumi Ohka.

text: In practice, the propagation characteristics of these radio waves vary substantially depending on the exact frequency and the strength of the transmitted signal (a function of both the transmitter and the antenna characteristics). Broadcast FM radio, at comparatively low frequencies of around 100 MHz, are less affected by the presence of buildings and forests.

text: In practice, the propagation characteristics of these radio waves vary substantially depending on the exact frequency and the strength of the transmitted signal (a function of both the transmitter and the antenna characteristics). Broadcast

text: FM

text: radio, at comparatively low frequencies of around 100 MHz, are less affected by the presence of buildings and forests.

text: On 1 March 1976, two high-power medium-wave stations in the Brunei-Muara District began transmission, expanding the coverage of radio and television services to almost 100% of the country.

text: On 1 March 1976, two high-power medium-wave stations in the

text: Brunei-Muara District

text: began transmission, expanding the coverage of radio and television services to almost 100% of the country.

text: A typical parabolic antenna consists of a metal parabolic reflector with a small feed antenna suspended in front of the reflector at its focus, pointed back toward the reflector. The reflector is a metallic surface formed into a paraboloid of revolution and usually truncated in a circular rim that forms the diameter of the antenna.  In a transmitting antenna, radio frequency current from a transmitter is supplied through a transmission line cable to the feed antenna, which converts it into radio waves.  The radio waves are emitted back toward the dish by the feed antenna and reflect off the dish into a parallel beam. In a receiving antenna the incoming radio waves bounce off the dish and are focused to a point at the feed antenna, which converts them to electric currents which travel through a transmission line to the radio receiver.

text: A typical parabolic antenna consists of a metal

text: parabolic reflector

text: with a small

text: feed antenna

text: suspended in front of the reflector at its focus, pointed back toward the reflector. The reflector is a metallic surface formed into a

text: paraboloid

text: of revolution and usually truncated in a circular rim that forms the diameter of the antenna.  In a transmitting antenna,

text: radio frequency

text: current

text: from a

text: transmitter

text: is supplied through a

text: transmission line

text: cable to the

text: feed antenna

text: , which converts it into radio waves.  The radio waves are emitted back toward the dish by the feed antenna and reflect off the dish into a parallel beam. In a receiving antenna the incoming radio waves bounce off the dish and are focused to a point at the feed antenna, which converts them to electric currents which travel through a

text: transmission line

text: to the

text: radio receiver

text: Perkins is the PM drive time jazz radio personality and host for WRTI-FM Temple University Radio in Philadelphia. He has been with the station since 1997. His knowledge of jazz programming was instrumental to a significant increase in weekday Jazz listenership and a doubling of the Sunday Jazz audience for his time slot. Previously (1988 to 1997) Perkins hosted a well known Jazz radio show Saturday nights on WHYY-FM. Starting in Philadelphia Radio in 1969, Perkins joined WDAS/WDAS-FM as a Newsman and became the News Director after two years. He also became the Editorial Director after another year. His distinctive deep voice and progressive points of view became an on-air signature for the fast-growing FM and AM operations at WDAS/WDAS-FM over 19 years during the 1970s and 80s. Perkins got his career started in Detroit radio over five years from 1964 to 1969. After breaking in as a DJ and announcer at WGPR-FM, he then expanded to news at WCHB-AM while also working as jazz program director for its twin, WCHD-FM. Then he continued to grow working as newsman and assistant director at WJLB-AM in Detroit before his career path returned him to Philadelphia.

text: Perkins is the PM drive time jazz radio personality and host for WRTI-FM

text: Temple University

text: Radio in Philadelphia. He has been with the station since 1997. His knowledge of jazz programming was instrumental to a significant increase in weekday Jazz listenership and a doubling of the Sunday Jazz audience for his time slot. Previously (1988 to 1997) Perkins hosted a well known Jazz radio show Saturday nights on

text: WHYY-FM

text: . Starting in Philadelphia Radio in 1969, Perkins joined

text: WDAS

text: WDAS-FM

text: as a Newsman and became the News Director after two years. He also became the Editorial Director after another year. His distinctive deep voice and progressive points of view became an on-air signature for the fast-growing FM and AM operations at

text: WDAS

text: WDAS-FM

text: over 19 years during the 1970s and 80s. Perkins got his career started in Detroit radio over five years from 1964 to 1969. After breaking in as a DJ and announcer at WGPR-FM, he then expanded to news at WCHB-AM while also working as jazz program director for its twin, WCHD-FM. Then he continued to grow working as newsman and assistant director at WJLB-AM in Detroit before his career path returned him to Philadelphia.

text: In Siegen, the Westdeutscher Rundfunk (WDR) maintains a studio where regional radio and television news for South Westphalia is produced. The daily broadcast goes out in the "South Westphalia" regional window following the programme Aktuelle Stunde (a newsmagazine show) on WDR's third channel. Moreover, WDR also runs a transmission facility for VHF radio and television (once also medium wave) at the Giersberg.

text: In Siegen, the

text: Westdeutscher Rundfunk

text: (WDR) maintains a studio where regional radio and television news for South Westphalia is produced. The daily broadcast goes out in the "South Westphalia" regional window following the programme Aktuelle Stunde (a newsmagazine show) on WDR's third channel. Moreover, WDR also runs a transmission facility for

text: VHF

text: radio and television (once also

text: medium wave

text: ) at the Giersberg.

text: Among CBC Radio One stations on the AM dial around Canada, CBU (AM) serves the largest area of population, since 940 CBM (AM) in Montreal became CBME-FM 88.5 in 1998, followed by 740 CBL (AM) Toronto's move to the FM dial in 1999 as CBLA-FM on 99.1 FM.

text: Among CBC Radio One stations on the AM dial around Canada, CBU (AM) serves the largest area of population, since 940 CBM (AM) in

text: Montreal

text: became

text: CBME-FM

text: 88.5 in

text: , followed by 740 CBL (AM)

text: Toronto

text: 's move to the FM dial in

text: as

text: CBLA-FM

text: on 99.1 FM.

text: The release of the EAN by the Aerospace Defense Command or the Federal Preparedness Agency would initiate a process by which the common carriers would link otherwise independent networks such as ABC, CBS, and NBC into a single national network that even independent stations could receive programming from. "Broadcast stations would have used the two-tone Attention Signal on their assigned broadcast frequency to alert other broadcast stations to stand by for a message from the President." The transmission of programming on a broadcast station's assigned frequency, and the fact that television networks/stations and FM radio stations could participate, distinguished EBS from CONELRAD. EBS radio stations would not necessarily transmit on 640 or 1240 on the AM dial, and FM radio and television would carry the same audio program as AM radio stations did.

text: The release of the EAN by the Aerospace Defense Command or the Federal Preparedness Agency would initiate a process by which the common carriers would link otherwise independent networks such as

text: ABC

text: CBS

text: , and

text: NBC

text: into a single national network that even

text: independent stations

text: could receive programming from. "Broadcast stations would have used the two-tone Attention Signal on their assigned broadcast frequency to alert other broadcast stations to stand by for a message from the President." The transmission of programming on a broadcast station's assigned frequency, and the fact that television networks/stations and FM radio stations could participate, distinguished EBS from

text: CONELRAD

text: . EBS radio stations would not necessarily transmit on 640 or 1240 on the AM dial, and FM radio and television would carry the same audio program as AM radio stations did.

text: This managerial philosophy made the NatLab very different from all the other Philips facilities and laboratories. Unlike the other Philips labs, NatLab was more like the AT&T Bell Laboratories in the United States. The research was also not limited to industrial research; a good deal of fundamental research was also performed at NatLab, such as that of Bernard D. H. Tellegen and Balthasar van der Pol. Van der Pol was hired in 1922 to start a research program into radio technology. This research program resulted in publishable results in the areas of propagation of radio waves, electrical circuit theory, harmonics and a number of related, mathematical problems. Van der Pol also studied the effect of the curvature of the Earth on radio wave propagation.

text: This managerial philosophy made the NatLab very different from all the other Philips facilities and laboratories. Unlike the other Philips labs, NatLab was more like the AT&T Bell Laboratories in the United States. The research was also not limited to industrial research; a good deal of fundamental research was also performed at NatLab, such as that of

text: Bernard D. H. Tellegen

text: and

text: Balthasar van der Pol

text: . Van der Pol was hired in 1922 to start a research program into

text: radio technology

text: . This research program resulted in publishable results in the areas of propagation of radio waves, electrical circuit theory,

text: harmonics

text: and a number of related,

text: mathematical

text: problems. Van der Pol also studied the effect of the curvature of the Earth on radio wave propagation.

text: Parabolic antennas are also classified by the type of feed, that is, how the radio waves are supplied to the antenna:

text: Parabolic antennas are also classified by the type of

text: feed

text: , that is, how the radio waves are supplied to the antenna:

text: Selectivity became more important as spark transmitters were replaced by continuous wave transmitters which transmitted on a narrow band of frequencies, and broadcasting led to a proliferation of closely spaced radio stations crowding the radio spectrum.   Resonant transformers continued to be used as the bandpass filter in vacuum tube radios, and new forms such as the variometer were invented.    Another advantage of the double-tuned transformer for AM reception was that when properly adjusted it had a "flat top" frequency response curve as opposed to the "peaked" response of a single tuned circuit.  This allowed it to pass the sidebands of AM modulation on either side of the carrier with little distortion, unlike a single tuned circuit which attenuated the higher audio frequencies.   Until recently the bandpass filters in the superheterodyne circuit used in all modern receivers were made with resonant transformers, called IF transformers.

text: Selectivity became more important as spark transmitters were replaced by

text: continuous wave

text: transmitters which transmitted on a narrow band of frequencies, and broadcasting led to a proliferation of closely spaced radio stations crowding the radio spectrum.   Resonant transformers continued to be used as the bandpass filter in vacuum tube radios, and new forms such as the

text: variometer

text: were invented.    Another advantage of the double-tuned transformer for AM reception was that when properly adjusted it had a "flat top" frequency response curve as opposed to the "peaked" response of a single tuned circuit.  This allowed it to pass the

text: sideband

text: s of AM modulation on either side of the

text: carrier

text: with little distortion, unlike a single tuned circuit which attenuated the higher audio frequencies.   Until recently the bandpass filters in the superheterodyne circuit used in all modern receivers were made with resonant transformers, called

text: IF transformers

text: Since radio waves go over borders, international agreements control radio transmissions. In European countries like Germany often the national Post Office is the regulating authority. In the United States broadcast and industrial transmitters are regulated by the Federal Communications Commission (FCC). In Canada technical aspects of broadcast and radio transmitters are controlled by Industry Canada, but broadcast content is regulated separately by the Canadian Radio-television and Telecommunications Commission (CRTC). In Australia transmitters, spectrum, and content are controlled by the Australian Communications and Media Authority (ACMA). The International Telecommunication Union (ITU) helps managing the radio-frequency spectrum internationally.

text: Since radio waves go over borders, international agreements control radio transmissions. In European countries like

text: Germany

text: often the national Post Office is the regulating authority. In the

text: United States

text: broadcast and industrial transmitters are regulated by the

text: Federal Communications Commission

text: (FCC). In

text: Canada

text: technical aspects of broadcast and radio transmitters are controlled by

entity_name: Innovation, Science and Economic Development Canada

text: Industry Canada

text: , but broadcast content is regulated separately by the

text: (CRTC). In Australia transmitters, spectrum, and content are controlled by the

entity_name: Australian Communications and Media Authority

text: Australian Communications and Media Authority

text: (ACMA). The

text: International Telecommunication Union

text: (ITU) helps managing the radio-frequency spectrum internationally.

text: The first primitive radio transmitters (called Hertzian oscillators) were built by German physicist Heinrich Hertz in 1887 during his pioneering investigations of radio waves.  These generated radio waves by a high voltage spark between two conductors.  Beginning in 1895 Guglielmo Marconi developed the first practical radio communication systems using spark transmitters.  They couldn't transmit audio and instead transmitted information by telegraphy, the operator spelling out text messages in Morse code.    These spark-gap transmitters were used during the first three decades of radio (1887-1917), called the wireless telegraphy or "spark" era.  Because they generated damped waves, spark transmitters were electrically "noisy"; their energy was spread over a broad band of frequencies, creating radio noise which interfered with other transmitters.  Two short-lived competing transmitter technologies came into use after the turn of the century, which were the first continuous wave transmitters: the Alexanderson alternator and Poulsen arc transmitters, which were used into the 1920s.

text: The first primitive radio transmitters (called Hertzian oscillators) were built by German physicist

text: Heinrich Hertz

text: in 1887 during his pioneering investigations of radio waves.  These generated radio waves by a high voltage

text: spark

text: between two conductors.  Beginning in 1895

text: Guglielmo Marconi

text: developed the first practical radio communication systems using spark transmitters.  They couldn't transmit

text: audio

text: and instead transmitted information by

text: telegraphy

text: , the operator spelling out text messages in

text: Morse code

text: .    These

text: spark-gap transmitter

text: s were used during the first three decades of radio (1887-1917), called the

text: wireless telegraphy

text: or "spark" era.  Because they generated

text: damped wave

text: s, spark transmitters were electrically "noisy"; their energy was spread over a broad band of

text: frequencies

text: , creating

text: radio noise

text: which interfered with other transmitters.  Two short-lived competing transmitter technologies came into use after the turn of the century, which were the first

text: continuous wave

text: transmitters: the

text: Alexanderson alternator

text: and

text: Poulsen arc

text: transmitters, which were used into the 1920s.

text: 1888: Heinrich Hertz demonstrates the existence of electromagnetic waves by building an apparatus that produced and detected UHF radio waves (or microwaves in the UHF region). He also found that radio waves could be transmitted through different types of materials and were reflected by others, the key to radar. His experiments explain reflection, refraction, polarization, interference, and velocity of electromagnetic waves.

text: Heinrich Hertz

text: demonstrates the existence of electromagnetic waves by building an apparatus that produced and detected UHF radio waves (or microwaves in the UHF region). He also found that radio waves could be transmitted through different types of materials and were reflected by others, the key to

text: radar

text: . His experiments explain

text: reflection

text: refraction

text: polarization

text: interference

text: , and

text: velocity

text: of electromagnetic waves.

text: It was originally used to transmit Southern Television, and later TVS, until the end of VHF television transmissions in the UK at the beginning of 1985. It now transmits Wave 105, 103.2 Capital FM, Sam FM, Isle of Wight Radio, the local Arqiva (NOW S. Hampshire) DAB multiplex and the national Digital One DAB multiplex.

text: It was originally used to transmit

text: Southern Television

text: , and later

text: TVS

text: , until the end of

text: VHF

text: television

text: transmissions in the UK at the beginning of 1985. It now transmits

text: Wave 105

text: 103.2 Capital FM

text: Sam FM

text: Isle of Wight Radio

text: , the local

text: Arqiva

text: (NOW S. Hampshire) DAB multiplex and the national

text: Digital One

text: DAB multiplex.

text: Diffraction refers to various phenomena which occur when a wave encounters an obstacle or a slit. It is defined as the bending of light around the corners of an obstacle or aperture into the region of geometrical shadow of the obstacle. In classical physics, the diffraction phenomenon is described as the interference of waves according to the Huygens–Fresnel principle. These characteristic behaviors are exhibited when a wave encounters an obstacle or a slit that is comparable in size to its wavelength. Similar effects occur when a light wave travels through a medium with a varying refractive index, or when a sound wave travels through a medium with varying acoustic impedance. Diffraction occurs with all waves, including sound waves, water waves, and electromagnetic waves such as visible light, X-rays and radio waves.

text: Diffraction refers to various phenomena which occur when a wave encounters an obstacle or a slit. It is defined as the bending of light around the corners of an obstacle or aperture into the region of geometrical shadow of the obstacle. In classical physics, the diffraction phenomenon is described as the

text: interference

text: of waves according to the

text: Huygens–Fresnel principle

text: . These characteristic behaviors are exhibited when a wave encounters an obstacle or a slit that is comparable in size to its

text: wavelength

text: . Similar effects occur when a light wave travels through a medium with a varying

text: refractive index

text: , or when a

text: sound wave

text: travels through a medium with varying

text: acoustic impedance

text: . Diffraction occurs with all waves, including sound waves,

text: water waves

text: , and

text: electromagnetic waves

text: such as

text: visible light

text: X-ray

text: s and

text: radio waves

text: Antennas are required by any radio receiver or transmitter to couple its electrical connection to the electromagnetic field. Radio waves are electromagnetic waves which carry signals through the air (or through space) at the speed of light with almost no transmission loss. Radio transmitters and receivers are used to convey signals (information) in systems including broadcast (audio) radio, television, mobile telephones, Wi-Fi (WLAN) data networks, trunk lines and point-to-point communications links (telephone, data networks), satellite links, many remote controlled devices such as garage door openers, and wireless remote sensors, among many others. Radio waves are also used directly for measurements in technologies including radar, GPS, and radio astronomy. In each and every case, the transmitters and receivers involved require antennas, although these are sometimes hidden (such as the antenna inside an AM radio or inside a laptop computer equipped with Wi-Fi).

text: Antennas are required by any radio receiver or transmitter to couple its electrical connection to the electromagnetic field.

text: Radio

text: waves are

text: electromagnetic waves

text: which carry signals through the air (or through space) at the

text: speed of light

text: with almost no

text: transmission loss

text: . Radio transmitters and receivers are used to convey signals (information) in systems including broadcast (audio) radio,

text: television

text: mobile telephones

text: Wi-Fi

text: WLAN

text: ) data networks,

text: trunk lines

text: and point-to-point communications links (telephone, data networks), satellite links, many

text: remote controlled

text: devices such as

text: garage door opener

text: s, and wireless remote sensors, among many others. Radio waves are also used directly for measurements in technologies including

text: radar

text: GPS

text: , and

text: radio astronomy

text: . In each and every case, the transmitters and receivers involved require antennas, although these are sometimes hidden (such as the antenna inside an AM radio or inside a laptop computer equipped with Wi-Fi).

text: In order to receive radio signals, for instance from AM/FM radio stations, a radio antenna must be used. However, since the antenna will pick up thousands of radio signals at a time, a radio tuner is necessary to tune in a particular signal. This is typically done via a resonator (in its simplest form, a circuit with a capacitor, inductor, or crystal oscillator, but many modern radios use Phase Locked Loop systems). The resonator is configured to resonate at a particular frequency, allowing the tuner to amplify sine waves at that radio frequency and ignore other sine waves. Usually, either the inductor or the capacitor of the resonator is adjustable, allowing the user to change the frequency at which it resonates.

text: In order to receive radio signals, for instance from

text: AM

text: FM

text: radio stations, a

text: radio antenna

text: must be used. However, since the antenna will pick up thousands of radio signals at a time, a

text: radio tuner

text: is necessary to tune in a particular signal. This is typically done via a

text: resonator

text: (in its simplest form, a circuit with a

text: capacitor

text: inductor

text: , or

text: crystal oscillator

text: , but many modern radios use

text: Phase Locked Loop

text: systems). The resonator is configured to resonate at a particular frequency, allowing the tuner to amplify sine waves at that radio frequency and ignore other sine waves. Usually, either the inductor or the capacitor of the resonator is adjustable, allowing the user to change the frequency at which it resonates.

text: The prediction that light represented a transmission of energy in wave form through a "luminiferous ether", and the seeming confirmation of that prediction with Helmholtz student Heinrich Hertz's 1888 detection of electromagnetic radiation, was a major triumph for physical theory and raised the possibility that even more fundamental theories based on the field could soon be developed. Experimental confirmation of Maxwell's theory was provided by Hertz, who generated and detected electric waves in 1886 and verified their properties, at the same time foreshadowing their application in radio, television, and other devices. In 1887, Heinrich Hertz discovered the photoelectric effect. Research on the electromagnetic waves began soon after, with many scientists and inventors conducting experiments on their properties. In the mid to late 1890s Guglielmo Marconi developed a radio wave based wireless telegraphy system (see invention of radio).

text: The prediction that light represented a transmission of energy in wave form through a "

text: luminiferous ether

text: ", and the seeming confirmation of that prediction with Helmholtz student

text: Heinrich Hertz

text: 's 1888 detection of

text: electromagnetic radiation

text: , was a major triumph for physical theory and raised the possibility that even more fundamental theories based on the field could soon be developed. Experimental confirmation of Maxwell's theory was provided by Hertz, who generated and detected electric waves in 1886 and verified their properties, at the same time foreshadowing their application in radio, television, and other devices. In 1887, Heinrich Hertz discovered the

text: photoelectric effect

text: . Research on the electromagnetic waves began soon after, with many scientists and inventors conducting experiments on their properties. In the mid to late 1890s

text: Guglielmo Marconi

text: developed a

text: radio wave

text: based

text: wireless telegraphy

text: system (see

text: invention of radio

text: In the United States, television is available via broadcast (also known as "over-the-air") – the earliest method of receiving television programming, which merely requires an antenna and an equipped internal or external tuner capable of picking up channels that transmit on the two principal broadcast bands, very high frequency (VHF) and ultra high frequency (UHF), in order to receive the signal – and four conventional types of multichannel subscription television: cable, unencrypted satellite ("free-to-air"), direct-broadcast satellite television and IPTV (internet protocol television). There are also competing video services on the World Wide Web, which have become an increasingly popular mode of television viewing since the late 2000s, particularly with younger audiences as an alternative or a supplement to the aforementioned traditional forms of viewing television content.

text: In the United States, television is available via

text: broadcast

text: (also known as "over-the-air") – the earliest method of receiving television programming, which merely requires an

text: antenna

text: and an equipped internal or external tuner capable of picking up channels that transmit on the two principal broadcast bands,

text: very high frequency

text: (VHF) and

text: ultra high frequency

text: (UHF), in order to receive the signal – and four conventional types of multichannel subscription television:

text: cable

text: unencrypted satellite

text: free-to-air

text: direct-broadcast satellite television

text: and

text: IPTV

text: (internet protocol television). There are also competing video services on the

text: World Wide Web

text: , which have become an increasingly popular mode of television viewing since the late 2000s, particularly with younger audiences as an alternative or a supplement to the aforementioned traditional forms of viewing television content.

text: FEBC currently operates a total of 41 AM and FM stations worldwide and also broadcast international programs in 149 languages via short wave radio from two major transmitter sites, several locations in the Philippines, and one in Saipan ().

text: FEBC currently operates a total of 41 AM and FM stations worldwide and also broadcast international programs in 149 languages via short wave radio from two major transmitter sites, several locations in the Philippines, and one in

text: Saipan

text: Most Apex stations operated under experimental licenses, and were affiliated with and subsidized by commercially licensed stations. In 1934, Buffalo, New York's W8XH, WBEN's ultra short wave station, became the first 5-meter station to air a regular schedule. It is a direct predecessor of current Buffalo FM adult contemporary station WTSS. In 1936, Milwaukee's W9XAZ (a service of The Milwaukee Journal's WTMJ (AM), which eventually became current day FM station WKTI-FM at 94.5) became the first Apex station to originate its own programming on a regular basis. By 1939, Apex stations were operating in 34 cities in 22 states. Apex radio broadcasting's goal of high fidelity sound was later realized by frequency modulation (FM), which operated at 42–50 MHz (later 88–106 MHz, 88–108 MHz later still, and currently 87.8–108 MHz), immediately above the Apex band of frequencies. The FCC in 1939 began encouraging Apex stations broadcasting in AM to consider the change to the technically superior FM system.

text: Most Apex stations operated under experimental licenses, and were affiliated with and subsidized by commercially licensed stations. In 1934,

text: Buffalo, New York

text: 's

text: WBEN

text: 's ultra short wave station, became the first 5-meter station to air a regular schedule. It is a direct predecessor of current Buffalo FM adult contemporary station

text: WTSS

text: . In 1936,

text: Milwaukee

text: 's W9XAZ (a service of

text: The Milwaukee Journal

text: 's

text: WTMJ (AM)

text: , which eventually became current day FM station

text: WKTI-FM

text: at 94.5) became the first Apex station to originate its own programming on a regular basis. By 1939, Apex stations were operating in 34 cities in 22 states. Apex radio broadcasting's goal of high fidelity sound was later realized by

text: frequency modulation

text: (FM), which operated at 42–50 MHz (later 88–106 MHz, 88–108 MHz later still, and currently 87.8–108 MHz), immediately above the Apex band of frequencies. The FCC in 1939 began encouraging Apex stations

text: broadcasting in AM

text: to consider the change to the technically superior

text: FM system

text: The station first signed on the air on November 24, 1948, originally broadcasting on VHF channel 5. The station's transmitter originally broadcast at 24,100 watts. WAVE was the first television station to sign on in the state of Kentucky, and the 41st to debut in the United States. It was founded by the Norton family, who had signed on WAVE radio (970 AM, now WGTK) in 1932. The station has been a primary NBC affiliate since its debut, owing to its sister radio station's longtime affiliation with the NBC Red Network; however, it also initially carried secondary affiliations with ABC, CBS and the DuMont Television Network.

text: The station first signed on the air on November 24, 1948, originally broadcasting on VHF channel 5. The station's transmitter originally broadcast at 24,100 watts. WAVE was the first television station to sign on in the state of Kentucky, and the 41st to debut in the United States. It was founded by the Norton family, who had signed on WAVE radio (970 AM, now

text: WGTK

text: ) in 1932. The station has been a primary NBC affiliate since its debut, owing to its sister radio station's longtime affiliation with the

text: NBC Red Network

text: ; however, it also initially carried secondary affiliations with

text: ABC

text: CBS

text: and the

text: DuMont Television Network

text: A medium wave radio station is operated by All India Radio, with most programs in Tamil, English and Hindi. Five FM radio stations operate from Coimbatore - Rainbow FM from All India Radio, Suryan FM from Sun Network, Radio Mirchi, Radio City, and Hello FM. All these private radio stations air exclusively Tamil based programs, including film music. The range of these stations cover Coimbatore, Erode and Nilgiri districts of Tamil Nadu, and Palakkad and Wayanad districts of Kerala. Television relay started in 1985 from Delhi Doordarshan. In 1986, after inception of a repeater tower at Kodaikanal, telecast from Madras Doordarshan commenced. The people of Coimbatore witnessed the 1980 Olympics and 1983 Cricket World Cup on a giant screen in VOC Park when the city-based UMS developed a dish antenna for satellite signal reception. Currently television reception is through DTH or by cable, while Doordarshan reception is still available using an external antenna. In 2005, Doordarshan opened its studio in Coimbatore.

text: A medium wave radio station is operated by

text: All India Radio

text: FM radio

text: stations operate from Coimbatore -

text: Rainbow FM

text: from All India Radio,

text: Suryan FM

text: from

text: Sun Network

text: Radio Mirchi

text: Radio City

text: , and

text: Hello FM

text: Tamil

text: based programs, including film music. The range of these stations cover Coimbatore,

text: Erode

text: and

text: Nilgiri

text: districts of

text: Tamil Nadu

text: , and

text: Palakkad

text: and

text: Wayanad

text: districts of Kerala. Television relay started in 1985 from Delhi

text: Doordarshan

text: Kodaikanal

text: , telecast from Madras Doordarshan commenced. The people of Coimbatore witnessed the

text: 1980 Olympics

text: and

text: 1983 Cricket World Cup

text: on a giant screen in VOC Park when the city-based UMS developed a dish antenna for satellite signal reception. Currently television reception is through

text: DTH

text: WNYC (AM) broadcasts on 820 kHz.  It is a member of NPR and carries local and national news/talk programs.  Some hours the programming is simulcast on WNYC-FM & some hours different shows air on each station. WNYC is owned by New York Public Radio which is also the owner of WNYC-FM, WQXR-FM, New Jersey Public Radio, and the Jerome L. Greene Performance Space. Combined, New York Public Radio owns WNYC, WNYC-FM, WQXR-FM, WQXW, WNJT-FM, WNJP, WNJY, and WNJO.

text: WNYC (AM) broadcasts on 820

text: kHz

text: .  It is a member of

text: NPR

text: and carries local and national news/talk programs.  Some hours the programming is

text: simulcast

text: on

text: WNYC-FM

text: & some hours different shows air on each station. WNYC is owned by

text: New York Public Radio

text: which is also the owner of

text: WNYC-FM

text: WQXR-FM

text: New Jersey Public Radio

text: WQXR-FM

text: WQXW

text: WNJT-FM

text: WNJP

text: WNJY

text: , and

text: WNJO

text: The term spectrum was expanded to apply to other waves, such as sound waves that could also be measured as a function of frequency, frequency spectrum and power spectrum of a signal. The term now applies to any signal that can be measured or decomposed along a continuous variable such as energy in electron spectroscopy or mass to charge ratio in mass spectrometry. Spectrum is also used to refer to a graphical representation of the signal as a function of the dependent variable.

text: The term spectrum was expanded to apply to other

text: wave

text: s, such as

text: sound wave

text: s that could also be measured as a function of frequency,

text: frequency spectrum

text: and

text: power spectrum

text: of a signal. The term now applies to any signal that can be measured or decomposed along a continuous variable such as energy in

text: electron spectroscopy

text: or mass to charge ratio in

text: mass spectrometry

text: . Spectrum is also used to refer to a graphical representation of the signal as a function of the dependent variable.

text: Despite moving the long wave Daventry transmissions to Droitwich, and increasing the transmitters power, long wave reception from the Midlands remained poor in Cornwall. To this day, BBC Radio Four is not audible on long wave in most of Cornwall, and reception relies on a couple of low power repeater transmitters on medium wave (e.g. Lanner/Redruth MF on 756 KHz). Initially, the BBC National Programme replaced several local and regional services. However, although it launched BBC Regional Programme for the West in 1933, it transmitted it from the Washford transmitter. In the 1960s, it started an opt out from the then new BBC Radio Four (formerly the BBC Home Service during the morning daily news programme (Today), called Morning Sou'West. This opt out continued, long after other regional services had ceased on the BBC (only National services for Wales, Scotland and Northern Ireland remained). However, the opt-out stopped with the long-overdue launch of BBC Radio Cornwall and BBC Radio Devon on 17 January 1983.

text: Despite moving the

text: long wave

text: Daventry

text: transmissions to

text: Droitwich

text: , and increasing the transmitters power,

text: long wave

text: reception from the Midlands remained poor in Cornwall. To this day,

text: BBC Radio Four

text: is not audible on

text: long wave

text: in most of Cornwall, and reception relies on a couple of low power repeater transmitters on medium wave (e.g.

text: Lanner/Redruth MF

text: on 756

text: KHz

text: ). Initially, the

text: BBC National Programme

text: replaced several local and regional services. However, although it launched

text: BBC Regional Programme

text: for the

text: West

text: in 1933, it transmitted it from the

text: Washford

text: transmitter. In the 1960s, it started an opt out from the then new

text: BBC Radio Four

text: (formerly the

text: BBC Home Service

text: during the morning daily news programme (

text: Today

text: ), called

text: Morning Sou'West

text: . This opt out continued, long after other regional services had ceased on the BBC (only National services for

text: Wales

text: Scotland

text: and

text: Northern Ireland

text: remained). However, the opt-out stopped with the long-overdue launch of

text: BBC Radio Cornwall

text: and

text: BBC Radio Devon

text: on 17 January 1983.

text: Television broadcasting started in 1958 with every country in the former Yugoslavia having its own station. In Serbia, the state television station was known as Television Belgrade (RTB) and became known as Radio Television of Serbia after the breakup of Yugoslavia. The second channel was launched in 1972 and the Third in 1989. Under the Communists and Slobodan Milošević, state broadcasting was controlled by the ruling party. The RTS headquarters were bombed during the NATO action against Yugoslavia. The system developed from a public monopoly, with regional centres (TV Novi Sad, TV Pristina) into a dual, public and private system. The government, while suppressing the development of alternative statewide channels, allowed the broadcasts of regional and local commercial stations (who could profit from unlimited advertisement time to sell), as well as new pro-government local TV outlets. After the fall of Milošević, RTS became known as Nova RTS as an assertion of independence while B92 commenced broadcasting.

text: Television broadcasting started in 1958 with every country in the former Yugoslavia having its own station. In Serbia, the state television station was known as Television Belgrade (RTB) and became known as Radio Television of Serbia after the breakup of Yugoslavia. The second channel was launched in 1972 and the Third in 1989. Under the

text: Communists

text: and Slobodan Milošević, state broadcasting was controlled by the ruling party. The RTS headquarters were bombed during the NATO action against Yugoslavia. The system developed from a public monopoly, with regional centres (

text: TV Novi Sad

text: TV Pristina

text: ) into a dual, public and private system. The government, while suppressing the development of alternative statewide channels, allowed the broadcasts of regional and local commercial stations (who could profit from unlimited advertisement time to sell), as well as new pro-government local TV outlets. After the fall of Milošević, RTS became known as Nova RTS as an assertion of independence while B92 commenced broadcasting.

text: Fessenden, more than any other person, is responsible for developing amplitude modulation (AM) radio transmission around 1900.  While working to develop AM transmitters, he realized that the radio wave detectors used in existing radio receivers were not suitable to receive AM signals.  The radio transmitters of the time transmitted information by radiotelegraphy; the transmitter was turned on and off by the operator using a switch called a telegraph key producing pulses of radio waves, to transmit text data using Morse code.  Thus receivers didn't have to extract an audio signal from the radio signal, but only detected the presence or absence of the radio frequency to produce "clicks" in the earphone representing the pulses of Morse code.  The device that did this was called a "detector".  The detector used in receivers of that day, called a coherer, simply acted as a switch, that conducted current in the presence of radio waves, and thus did not have the capability to demodulate, or extract the audio signal from, an amplitude modulated radio wave.

text: Fessenden, more than any other person, is responsible for developing

text: amplitude modulation

text: (AM) radio transmission around 1900.  While working to develop AM transmitters, he realized that the radio wave detectors used in existing radio receivers were not suitable to receive AM signals.  The radio transmitters of the time transmitted information by

text: radiotelegraphy

text: ; the transmitter was turned on and off by the operator using a switch called a

text: telegraph key

text: producing pulses of radio waves, to transmit text data using

text: Morse code

text: .  Thus receivers didn't have to extract an audio signal from the radio signal, but only detected the presence or absence of the radio frequency to produce "clicks" in the earphone representing the pulses of Morse code.  The device that did this was called a "detector".  The detector used in receivers of that day, called a

text: coherer

text: , simply acted as a switch, that conducted current in the presence of radio waves, and thus did not have the capability to

text: demodulate

text: , or extract the audio signal from, an amplitude modulated radio wave.

text: WPEN and WMGK Philadelphia were among the company's earliest major-market clients. Within a few years, JAM jingles were used by many of the most listened-to radio stations of all time including WABC, WPLJ, and WHTZ in New York, WLS AM and WLS FM in Chicago, KIIS AM & FM in Los Angeles, and BBC Radio 1 and Radio 2 in the UK. JAM also created themes and jingles for many syndicated radio programs, including those hosted by Casey Kasem, Dick Clark, Rick Dees, Dick Bartley, Bob Costas, Scott Shannon, Dan Ingram and others. In addition, JAM has worked for various TV clients including ABC, NBC (David Letterman), VH-1 and more.

text: WPEN and WMGK Philadelphia were among the company's earliest major-market clients. Within a few years, JAM jingles were used by many of the most listened-to radio stations of all time including

text: WABC

text: WPLJ

text: , and

text: WHTZ

text: in New York,

text: WLS AM

text: and

text: WLS FM

text: in Chicago,

text: KIIS AM & FM

text: in Los Angeles, and

text: BBC

text: Radio 1

text: and

text: Radio 2

text: in the UK. JAM also created themes and jingles for many syndicated radio programs, including those hosted by

text: Casey Kasem

text: Dick Clark

text: Rick Dees

text: Dick Bartley

text: Bob Costas

text: Scott Shannon

text: Dan Ingram

text: and others. In addition, JAM has worked for various TV clients including

text: ABC

text: NBC

text: David Letterman

text: and more.

text: The television in Greece began in 1966. Nevertheless the first TV series was aired in 1970 and was the series To Spiti me ton Foinika, aired by YENED. The next series was O Kyrios Synigoros in the same year. The first years of television there were only public channels. The first channels were the channel EIR and the TED, the channel of armed forces. Few years later TED renamed to YENED and EIR became EIRT. The public channels renamed again after the coming of PASOK in the power and they became ERT1 and ERT2. Famous TV-series of the period of public television are: O Agnostos Polemos, I Geitonia Mas, Louna Park, Christ Recrucified, Methoriakos Stathmos, oi Pantheoi. In 1989, Greek television entered in a new period, the period of private television. The first private TV channels started to broadcast in 1989. After the creation of private channels the most series were played by them. The period 1995–2009 is the best period of the Greek television and frequently characterized as the golden age of the Greek TV. Then, many series were shot with expensive productions. After 2010, the Greek debt crisis affected the Greek television and the productions decreased dramatically.

text: The television in Greece began in 1966. Nevertheless the first TV series was aired in 1970 and was the series

text: To Spiti me ton Foinika

text: , aired by

text: YENED

text: . The next series was

text: O Kyrios Synigoros

text: in the same year. The first years of television there were only

text: public channels

text: . The first channels were the channel EIR and the TED, the channel of armed forces. Few years later TED renamed to YENED and EIR became EIRT. The public channels renamed again after the coming of

text: PASOK

text: in the power and they became ERT1 and ERT2. Famous TV-series of the period of public television are:

text: O Agnostos Polemos

text: I Geitonia Mas

text: Louna Park

text: Christ Recrucified

text: Methoriakos Stathmos

text: oi Pantheoi

text: . In 1989, Greek television entered in a new period, the period of private television. The first private TV channels started to broadcast in 1989. After the creation of private channels the most series were played by them. The period 1995–2009 is the best period of the Greek television and frequently characterized as the golden age of the Greek TV. Then, many series were shot with expensive productions. After 2010, the

text: Greek debt crisis

text: affected the Greek television and the productions decreased dramatically.

text: In 1890, Édouard Branly demonstrated what he later called the "radio-conductor," which Lodge in 1893 named the coherer, the first sensitive device for detecting radio waves. Shortly after the experiments of Hertz, Branly discovered that loose metal filings, which in a normal state have a high electrical resistance, lose this resistance in the presence of electric oscillations and become practically conductors of electricity. This Branly showed by placing metal filings in a glass box or tube, and making them part of an ordinary electric circuit. According to the common explanation, when electric waves are set up in the neighborhood of this circuit, electromotive forces are generated in it which appear to bring the filings more closely together, that is, to cohere, and thus their electrical resistance decreases, from which cause this piece of apparatus was termed by Sir Oliver Lodge a coherer. Hence the receiving instrument, which may be a telegraph relay, that normally would not indicate any sign of current from the small battery, can be operated when electric oscillations are set up. Branly further found that when the filings had once cohered they retained their low resistance until shaken apart, for instance, by tapping on the tube. The coherer, however, was not sensitive enough to be used reliably as radio developed.

text: In 1890,

text: Édouard Branly

text: demonstrated what he later called the "radio-conductor," which Lodge in 1893 named the

text: coherer

text: , the first sensitive device for detecting radio waves. Shortly after the experiments of Hertz, Branly discovered that loose metal filings, which in a normal state have a high electrical resistance, lose this resistance in the presence of electric oscillations and become practically conductors of electricity. This Branly showed by placing metal filings in a glass box or tube, and making them part of an ordinary electric circuit. According to the common explanation, when electric waves are set up in the neighborhood of this circuit, electromotive forces are generated in it which appear to bring the filings more closely together, that is, to cohere, and thus their electrical resistance decreases, from which cause this piece of apparatus was termed by

text: Sir Oliver Lodge

text: a coherer. Hence the receiving instrument, which may be a telegraph relay, that normally would not indicate any sign of current from the small battery, can be operated when electric oscillations are set up. Branly further found that when the filings had once cohered they retained their low resistance until shaken apart, for instance, by tapping on the tube. The coherer, however, was not sensitive enough to be used reliably as radio developed.

text: Ground conductivity is an extremely important factor in determining the field strength and propagation of surface wave (ground wave) radio transmissions.  Low frequency (30–300 kHz) and medium frequency (300–3000 kHz) radio transmissions are particularly reliant on good ground conductivity as their primary propagation is by surface wave.  It also  affects the real world radiation pattern of high frequency (3-30 MHz) antennas, as the so called "takeoff angle" is not an inherent property of the antenna but a result of a ground reflection. For this reason ITU publishes an extensive world atlas of ground conductivities.

text: Ground conductivity is an extremely important factor in determining the field strength and propagation of

text: surface wave

text: (ground wave) radio transmissions.

text: Low frequency

text: (30–300 kHz) and

text: medium frequency

text: (300–3000 kHz) radio transmissions are particularly reliant on good ground conductivity as their primary propagation is by surface wave.  It also  affects the real world radiation pattern of

text: high frequency

text: (3-30 MHz) antennas, as the so called "takeoff angle" is not an inherent property of the antenna but a result of a ground reflection. For this reason ITU publishes an extensive world atlas of ground conductivities.

text: A television set, also called a television receiver, television, TV set, TV, or "telly", is a device that combines a tuner, display, an amplifier, and speakers for the purpose of viewing television and hearing its audio components. Introduced in late 1920's in mechanical form, television sets became a popular consumer product after World War II in electronic form, using cathode ray tubes. The addition of color to broadcast television after 1953 further increased the popularity of television sets and an outdoor antenna became a common feature of suburban homes. The ubiquitous television set became the display device for recorded media in the 1970s, such as Betamax and VHS, which enabled viewers to record TV shows and watch prerecorded movies. In the subsequent decades, TVs were used to watch DVDs and Blu-ray Discs of movies and other content. Major TV manufacturers announced the discontinuation of CRT, DLP, plasma and fluorescent-backlit LCDs by the mid-2010s. Televisions since 2010s mostly use LEDs. LEDs are expected to be gradually replaced by OLEDs in near future.

text: A television set, also called a television receiver, television, TV set, TV, or "telly", is a device that combines a tuner, display, an amplifier, and speakers for the purpose of viewing television and hearing its audio components. Introduced in late 1920's in

text: mechanical

text: cathode ray tube

text: s. The addition of color to broadcast television after 1953 further increased the popularity of television sets and an outdoor antenna became a common feature of suburban homes. The ubiquitous television set became the display device for recorded media in the 1970s, such as

text: Betamax

text: and

text: VHS

text: , which enabled viewers to record TV shows and watch prerecorded movies. In the subsequent decades, TVs were used to watch

text: DVD

text: s and

text: Blu-ray Disc

text: s of movies and other content. Major TV manufacturers announced the discontinuation of CRT, DLP, plasma and fluorescent-backlit LCDs by the mid-2010s. Televisions since 2010s mostly use

text: LEDs

text: . LEDs are expected to be gradually replaced by OLEDs in near future.

text: Pittsburgh radio has long been dominated by KDKA 1020 AM. However, as of early 2006 the station is no longer No. 1 in the ratings. KQV 1410 AM, now an all-news outlet, was Pittsburgh's dominant Top 40 station throughout the 1960s. On the FM dial, album-rock WDVE (102.5 DVE), modern rock WXDX (105.9 The X), adult contemporary WBZZ (Star 100.7), pop and hip-hop WKST-FM (96.1 KissFM) and Pittsburgh Sports Talk on (93.7 The Fan) KDKA-FM FM talk radio is available in the Pittsburgh market at WPGB (104.7 FM NewsTalk). Pittsburgh is also home to three public radio stations: WESA, the local NPR station; WQED-FM, a listener-supported commercial-free classical music station; and WYEP 91.3FM, the nation's third-largest independent "adult album alternative" (AAA) station, which hosts the locally produced environmental radio show The Allegheny Front and also carries some NPR programming. The Radio Information Service, broadcasting on a subcarrier of WESA provides special programming for the blind and print impaired. Additionally, Pittsburgh hosts the non-commercial radio stations WRCT (affiliated with Carnegie Mellon University) and WPTS (affiliated with the University of Pittsburgh).

text: Pittsburgh radio has long been dominated by KDKA 1020 AM. However, as of early 2006 the station is no longer No. 1 in the ratings.

text: KQV

text: 1410 AM, now an all-news outlet, was Pittsburgh's dominant Top 40 station throughout the 1960s. On the

text: FM

text: dial, album-rock

text: WDVE

text: (102.5 DVE), modern rock

text: WXDX

text: (105.9 The X), adult contemporary

text: WBZZ

text: (Star 100.7), pop and hip-hop

text: WKST-FM

text: (96.1 KissFM) and Pittsburgh Sports Talk on (93.7 The Fan)

text: KDKA-FM

text: FM talk radio is available in the Pittsburgh market at

text: WPGB

text: (104.7 FM NewsTalk). Pittsburgh is also home to three public radio stations:

text: WESA

text: , the local

text: NPR

text: station;

text: WQED-FM

text: , a listener-supported commercial-free classical music station; and

text: WYEP

text: 91.3FM, the nation's third-largest independent "adult album alternative" (AAA) station, which hosts the locally produced environmental radio show The Allegheny Front and also carries some NPR programming. The

text: Radio Information Service

text: , broadcasting on a

text: subcarrier

text: of WESA provides special programming for the blind and print impaired. Additionally, Pittsburgh hosts the non-commercial radio stations

text: WRCT

text: (affiliated with

text: Carnegie Mellon University

text: ) and

text: WPTS

text: (affiliated with the

text: University of Pittsburgh

text: In a radio antenna, the feed line is the cable or other transmission line that connects the antenna with the radio transmitter or receiver.   In a transmitting antenna, it feeds the radio frequency (RF) current from the transmitter to the antenna, where it is radiated as radio waves.  In a receiving antenna it transfers the tiny RF voltage induced in the antenna by the radio wave to the receiver.  In order to carry RF current efficiently, feed lines are made of specialized types of cable called transmission line.    The most widely used types of feed line are coaxial cable, twin-lead, ladder line, and at microwave frequencies, waveguide.

text: In a radio

text: antenna

text: , the feed line is the cable or other

text: transmission line

text: that connects the antenna with the radio

text: transmitter

text: or

text: receiver

text: .   In a transmitting antenna, it feeds the

text: radio frequency

text: (RF)

text: current

text: from the transmitter to the antenna, where it is radiated as

text: radio wave

text: s.  In a receiving antenna it transfers the tiny RF voltage induced in the antenna by the radio wave to the receiver.  In order to carry RF current efficiently, feed lines are made of specialized types of cable called

text: transmission line

text: .    The most widely used types of feed line are

text: coaxial cable

text: twin-lead

text: ladder line

text: , and at

text: microwave

text: frequencies,

text: waveguide

text: FM started in Australia in 1947 but did not catch on and was shut down in 1961 to expand the television band: some TV stations were allocated within the VHF band (98–108 MHz). The official policy on FM at the time was to eventually introduce it on another band, which would have required FM tuners custom-built for Australia. This policy was finally reversed and FM broadcasting was reopened in 1975 using the VHF band, after the few encroaching TV stations had been moved. Subsequently, it developed steadily until in the 1980s many AM stations transferred to FM due to its superior sound quality. Today, as elsewhere in the developed world, most urban Australian broadcasting is on FM, although AM talk stations are still very popular. Regional broadcasters still commonly operate AM stations due to the additional range the broadcasting method offers. Some stations in major regional centres simulcast on AM and FM bands. Digital radio using the DAB+ standard has been rolled out to capital cities.

text: FM started in

text: Australia

text: in 1947 but did not catch on and was shut down in 1961 to expand the

text: television

text: band: some TV stations were allocated within the VHF band (98–108 MHz). The official policy on FM at the time was to eventually introduce it on another band, which would have required FM tuners custom-built for Australia. This policy was finally reversed and FM broadcasting was reopened in 1975 using the VHF band, after the few encroaching TV stations had been moved. Subsequently, it developed steadily until in the 1980s many AM stations transferred to FM due to its superior sound quality. Today, as elsewhere in the developed world, most urban Australian broadcasting is on FM, although AM talk stations are still very popular. Regional broadcasters still commonly operate AM stations due to the additional range the broadcasting method offers. Some stations in major regional centres simulcast on AM and FM bands. Digital radio using the DAB+ standard has been rolled out to capital cities.

text: Vacuum diode rectifiers were widely used in power supplies in vacuum tube consumer electronic products, such as phonographs, radios, and televisions, for example the All American Five radio receiver, to provide the high DC plate voltage needed by other vacuum tubes.  "Full-wave" versions with two separate plates were popular because they could be used with a center-tapped transformer to make a full-wave rectifier.  Vacuum rectifiers were made for very high voltages, such as the high voltage power supply for the cathode ray tube of television receivers, and the kenotron used for power supply in X-ray equipment.  However, compared to modern semiconductor diodes, vacuum rectifiers have high internal resistance due to space charge and therefore high voltage drops, causing high power dissipation and low efficiency.  They are rarely able to handle currents exceeding 250 mA owing to the limits of plate power dissipation, and cannot be used for low voltage applications,  such as battery chargers. Another limitation of the vacuum tube rectifier is that the heater power supply often requires special arrangements to insulate it from the high voltages of the rectifier circuit.

text: Vacuum diode rectifiers were widely used in power supplies in vacuum tube consumer electronic products, such as phonographs, radios, and televisions, for example the

text: All American Five

text: radio receiver, to provide the high DC plate voltage needed by other vacuum tubes.  "Full-wave" versions with two separate plates were popular because they could be used with a center-tapped transformer to make a full-wave rectifier.  Vacuum rectifiers were made for very high voltages, such as the high voltage power supply for the

text: cathode ray tube

text: of

text: television

text: receivers, and the kenotron used for power supply in

text: X-ray

text: equipment.  However, compared to modern semiconductor diodes, vacuum rectifiers have high internal resistance due to

text: space charge

text: and therefore high voltage drops, causing high power dissipation and low efficiency.  They are rarely able to handle currents exceeding 250 mA owing to the limits of plate power dissipation, and cannot be used for low voltage applications,  such as battery chargers. Another limitation of the vacuum tube rectifier is that the heater power supply often requires special arrangements to insulate it from the high voltages of the rectifier circuit.

text: The core focus of the Spectrum Policy Task Force is to ensure the efficient and effective use of the radio spectrum. The radio spectrum currently being used plays a vital role in a vast amount of government and commercial services. These services include radio and television broadcasts, satellite communications, wireless networks, public safety communications, weather forecasting, etc. The radio spectrum is the section of the electromagnetic spectrum that spans from about 3 kilohertz to 300 gigahertz. Television broadcasts, radios, mobile phones, and military and government communication systems are best operated in the 100 MHZ to 3GHz radio spectrum. The current use of the spectrum is mostly focused on the lower 1% of these frequencies. With the gradual increases in technological innovation and wireless communication, the usable part of the radio spectrum has also been greatly expanded. From here on, there will only be gradual increases in the technology and devices that depend on the radio spectrum for their functionality. The National Telecommunication and Information Administration (NTIA) deals with radio spectrum policies on the international level as well as federal government use of the radio spectrum. The allocation of the radio spectrum differs around the globe, but since electromagnetic waves travel the same way through the air, spectrum management decisions are generally coordinated internationally. The Federal Communication Commission’s (FCC) primary focus is on all the nonfederal, state, and local governments’ use of the spectrum. To manage the spectrum, both the NTIA and FCC used the “command-and-control” approach; they dictated how each segment of the radio spectrum is used and who is eligible to use it. The command-and-control approach worked in the initial days of wireless communication, but in order to meet the needs of new technology innovations and modern mobile devices using wireless communication, a policy was required that was more consumer-oriented. The FCC formed a task force—the Spectrum Policy Task Force—whose primary role was to evaluate changes in the spectrum policy, ensure the efficient and effective use of the spectrum, and derive public benefit from the use of the spectrum.

text: The core focus of the Spectrum Policy Task Force is to ensure the efficient and effective use of the radio spectrum. The radio spectrum currently being used plays a vital role in a vast amount of government and commercial services. These services include radio and television

text: broadcasts

text: , satellite communications,

text: wireless network

text: s, public safety communications,

text: weather forecasting

text: , etc. The radio spectrum is the section of the

text: electromagnetic spectrum

text: that spans from about 3

text: kilohertz

text: to 300

text: gigahertz

text: . Television broadcasts, radios,

text: mobile phone

text: s, and

text: military

text: and government communication systems are best operated in the 100

text: MHZ

text: to 3

text: GHz

text: radio spectrum. The current use of the spectrum is mostly focused on the lower 1% of these frequencies. With the gradual increases in technological innovation and wireless communication, the usable part of the radio spectrum has also been greatly expanded. From here on, there will only be gradual increases in the technology and devices that depend on the radio spectrum for their functionality.

entity_name: National Telecommunications and Information Administration

text: The National Telecommunication and Information Administration (NTIA)

text: deals with radio spectrum policies on the international level as well as federal government use of the radio spectrum. The allocation of the radio spectrum differs around the globe, but since

text: electromagnetic wave

text: s travel the same way through the air, spectrum management decisions are generally coordinated internationally. The Federal Communication Commission’s (FCC) primary focus is on all the nonfederal, state, and local governments’ use of the spectrum. To manage the spectrum, both the NTIA and FCC used the “

text: command-and-control

text: ” approach; they dictated how each segment of the radio spectrum is used and who is eligible to use it. The command-and-control approach worked in the initial days of wireless communication, but in order to meet the needs of new technology innovations and modern

text: mobile device

text: s using wireless communication, a policy was required that was more consumer-oriented. The FCC formed a task force—the Spectrum Policy Task Force—whose primary role was to evaluate changes in the spectrum policy, ensure the efficient and effective use of the spectrum, and derive public benefit from the use of the spectrum.

text: According to Milliyet newspaper total number of radio stations in Turkey is 1078 (2010 figure). The main broadcaster is  Turkish Radio and Television Corporation (abbreviated TRT), a public broadcaster. TRT broadcasts 7 national, 6 regional and 5 international radio channels. TRT uses long wave, medium wave and FM band for the domestic broadcast. The short wave is reserved for international services (Voice of Turkey). The private companies however prefer FM band.

text: According to

text: Milliyet

text: newspaper total number of radio stations in Turkey is 1078 (2010 figure). The main broadcaster is

entity_name: Turkish Radio and Television Corporation

text: Turkish Radio and Television Corporation

text: (abbreviated TRT), a public broadcaster. TRT broadcasts 7 national, 6 regional and 5 international radio channels. TRT uses

text: long wave

text: medium wave

text: and

text: FM band

text: for the domestic broadcast. The

text: short wave

text: is reserved for international services (

text: Voice of Turkey

text: ). The private companies however prefer FM band.

text: Although this concept is based on an antenna receiving a radio frequency wave, knowing A directly supplies the (power) gain of that antenna. Due to reciprocity, an antenna's gain in receiving and transmitting are identical. Therefore A can just as well be used to compute the performance of a transmitting antenna. Note that A is a function of the direction of the radio wave relative to the orientation of the antenna, since the gain of an antenna varies according to its radiation pattern. When no direction is specified, A is understood to refer to its maximum value, with the antenna oriented so its main lobe, the axis of maximum sensitivity, is directed toward the source.

text: Although this concept is based on an antenna receiving a radio frequency wave, knowing A directly supplies the

text: (power) gain

text: of that antenna. Due to

text: reciprocity

text: , an antenna's gain in receiving and transmitting are identical. Therefore A can just as well be used to compute the performance of a transmitting antenna. Note that A is a function of the direction of the radio wave relative to the orientation of the antenna, since the gain of an antenna varies according to its

text: radiation pattern

text: . When no direction is specified, A is understood to refer to its maximum value, with the antenna oriented so its

text: main lobe

text: , the axis of maximum sensitivity, is directed toward the source.

text: The size of the counterpoise used for radio work depends on the wavelength of the transmit frequency.  With a monopole antenna the counterpoise functions as a ground plane, reflecting the radio waves radiated downward by the antenna.  To perform adequately, the counterpoise should extend at least half a wavelength from the antenna tower in all directions. In designing a counterpoise for an AM radio station, for example, AM broadcast-band radio waves are a maximum of  long. Therefore, the counterpoise should extend  from the tower to make a circle  in diameter.   Counterpoises are also used in high-voltage systems, such as lightning rods and Tesla coils.

text: The size of the counterpoise used for radio work depends on the

text: wavelength

text: of the transmit frequency.  With a monopole antenna the counterpoise functions as a

text: ground plane

text: , reflecting the radio waves radiated downward by the antenna.  To perform adequately, the counterpoise should extend at least half a wavelength from the antenna tower in all directions. In designing a counterpoise for an AM

text: radio station

text: , for example, AM broadcast-band radio waves are a maximum of  long. Therefore, the counterpoise should extend  from the tower to make a circle  in diameter.   Counterpoises are also used in high-voltage systems, such as

text: lightning rod

text: s and

text: Tesla coils

text: Sigma Designs develops and markets the Z-Wave protocol for home control. Z-Wave is a wireless radio frequency communications technology designed for control and status reading applications in residential and light commercial environments. Z-Wave has an alliance and more than 1,500 interoperable products in a certification program. On May 23, 2011, Sigma announced Japanese manufacturer Mitsumi as a licensed second source for Z-Wave technology. The company secured Verizon as a partner, with the telecom giant expected to roll out home control and security services through Z-Wave in the fall of 2011.

text: Sigma Designs develops and markets the

text: Z-Wave

text: protocol for home control. Z-Wave is a wireless

text: radio frequency

text: communications technology designed for control and status reading applications in residential and light commercial environments. Z-Wave has an alliance and more than 1,500 interoperable products in a certification program. On May 23, 2011, Sigma announced Japanese manufacturer

text: Mitsumi

text: as a licensed second source for Z-Wave technology. The company secured

text: Verizon

text: as a partner, with the telecom giant expected to roll out home control and security services through Z-Wave in the fall of 2011.

text: Anderson began as a DJ on Whiston Hospital Radio in Prescot, Merseyside. A year later, she joined Rock FM and went on to present radio shows across England, including Ocean FM, Power FM, Wave 105 and BBC Radio Solent (2009–2012).

text: Anderson began as a DJ on

text: Whiston

text: Hospital Radio

text: in

text: Prescot

text: Merseyside

text: . A year later, she joined

text: Rock FM

text: and went on to present radio shows across England, including

text: Ocean FM

text: Power FM

text: Wave 105

text: and

text: BBC Radio Solent

text: When a radio antenna is mounted above a conductive surface such as the earth, the radio waves directed down toward the surface reflect off it.  The radiation received at a distant point is the sum of two contributions: the waves that travel directly from the antenna to the point, and the waves that reach the point after reflecting off the ground plane.  Because of the reflection, these second waves appear to come from a second antenna behind the plane, just as a visible object in front of a flat mirror forms a virtual image that seems to lie behind the mirror.  The radiation pattern of the antenna is exactly the same as it would be if the ground plane were replaced by a mirror image of the antenna, located an equal distance behind the plane.   This second apparent source of radio waves is the image antenna.

text: When a radio antenna is mounted above a conductive surface such as the

text: earth

text: , the radio waves directed down toward the surface reflect off it.  The radiation received at a distant point is the sum of two contributions: the waves that travel directly from the antenna to the point, and the waves that reach the point after reflecting off the ground plane.  Because of the reflection, these second waves appear to come from a second antenna behind the plane, just as a visible object in front of a flat

text: mirror

text: forms a

text: virtual image

text: that seems to lie behind the mirror.  The

text: radiation pattern

text: of the antenna is exactly the same as it would be if the ground plane were replaced by a mirror image of the antenna, located an equal distance behind the plane.   This second apparent source of radio waves is the image antenna.

text: The Federal Communications Commission (FCC) in 1970 had limited the number of radio station one person or company could own to 1 AM and 1 FM locally, and 7 AM and 7 FM stations nationally. But due to extensive concentration of media ownership stemming from the Telecommunications Act of 1996, radio companies could own not more than 8 local stations. Among the major radio companies in the U.S. today are iHeartMedia (formerly Clear Channel Communications), Cumulus Media, Townsquare Media, and CBS Radio. See IBOC and HD Radio.

text: The

text: Federal Communications Commission

text: (FCC) in 1970 had limited the number of radio station one person or company could own to 1 AM and 1 FM locally, and 7 AM and 7 FM stations nationally. But due to extensive

text: concentration of media ownership

text: stemming from the

text: Telecommunications Act of 1996

text: , radio companies could own not more than 8 local stations. Among the major radio companies in the U.S. today are

text: iHeartMedia

text: (formerly Clear Channel Communications),

text: Cumulus Media

text: Townsquare Media

text: , and

text: CBS Radio

text: . See

text: IBOC

text: and

text: HD Radio

text: A television station is a type of broadcast station that broadcasts both audio and video to television receivers in a particular area.  Traditionally, TV stations made their broadcasts by sending specially-encoded radio signals over the air, called terrestrial television.  Individual television stations are usually granted licenses by a government agency to use a particular section of the radio spectrum (a channel) through which they send their signals.  Some stations use LPTV broadcast translators to retransmit to further areas.

text: A television station is a type of broadcast station that

text: broadcast

text: s both

text: audio

text: and

text: video

text: to

text: television

text: receiver

text: s in a particular area.  Traditionally, TV stations made their broadcasts by sending specially-encoded

text: radio

text: signals over the air, called

text: terrestrial television

text: .  Individual television stations are usually granted

text: license

text: s by a

text: government agency

text: to use a particular section of the

text: radio spectrum

text: (a

text: channel

text: ) through which they send their signals.  Some stations use

text: LPTV

text: broadcast translator

text: s to

text: retransmit

text: to further areas.

text: In radio, longwave, also written as long wave (in British and American parlance) or long-wave, and commonly abbreviated LW, refers to parts of the radio spectrum with relatively long wavelengths.  The term is an historic one, dating from the early 20th century, when the radio spectrum was considered to consist of long (LW), medium (MW) and short (SW) radio wavelengths.  Most modern radio systems and devices use wavelengths which would then have been considered 'ultra-short'.

text: In radio, longwave, also written as long wave (in

text: British

text: and

text: American

text: parlance) or long-wave, and commonly abbreviated LW, refers to parts of the

text: radio spectrum

text: with relatively long

text: wavelength

text: s.  The term is an historic one, dating from the early 20th century, when the radio spectrum was considered to consist of long (LW), medium (MW) and short (SW) radio wavelengths.  Most modern radio systems and devices use wavelengths which would then have been considered 'ultra-short'.

text: Radar applications use relatively high power pulse transmitters and sensitive receivers, so radar is operated on bands not used for other purposes.  Most radar bands are in the microwave part of the spectrum, although certain important applications for meteorology make use of powerful transmitters in the UHF band.Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Radio waves have frequencies as high as 300 GHz to as low as 3 kHz, though some definitions describe waves above 1 or 3 GHz as microwaves, or include waves of any lower frequency. At 300 GHz, the corresponding wavelength is 1 mm (0.039 in), and at 3 kHz is 100 km (62 mi). Like all other electromagnetic waves, they travel at the speed of light. Naturally occurring radio waves are generated by lightning, or by astronomical objects.

text: Radar

text: applications use relatively high power pulse transmitters and sensitive receivers, so radar is operated on bands not used for other purposes.  Most radar bands are in the

text: microwave

text: part of the spectrum, although certain important applications for

text: meteorology

text: make use of powerful transmitters in the UHF band.Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Radio waves have frequencies as high as 300 GHz to as low as 3 kHz, though some definitions describe waves above 1 or 3 GHz as microwaves, or include waves of any lower frequency. At 300 GHz, the corresponding wavelength is 1 mm (0.039 in), and at 3 kHz is 100 km (62 mi). Like all other electromagnetic waves, they travel at the speed of light. Naturally occurring radio waves are generated by lightning, or by astronomical objects.

text: The sale rumors were confirmed on October 16, 2012, when Family Radio announced that it would sell WFME to Atlanta-based Cumulus Media; the originally undisclosed price was later confirmed to be $40 million. In addition, Family Radio acquired Cumulus' WDVY (106.3 FM) in Mount Kisco, New York. The FCC approved the sale/station trade January 4, 2013, making 94.7 FM a sister station to Cumulus' two existing New York market stations, WABC and WPLJ. Four days later, on January 8, 2013, Cumulus completed the purchase of WFME. Family Radio programming on 94.7 FM ended at 3:40 p.m. on January 11, 2013; prior to signing off of the frequency, station manager Charlie Menut stated that the network's programming would be transferred to 106.3 FM, which became the new WFME on January 15, and that efforts to acquire an AM frequency that would cover the New York City area were being made. Two years later, in February 2015, Family Radio programming returned to the area via its acquisition of WQEW (1560 AM), a former Radio Disney outlet.

text: The sale rumors were confirmed on October 16, 2012, when Family Radio announced that it would sell WFME to

text: Atlanta

text: -based

text: Cumulus Media

text: ; the originally undisclosed price was later confirmed to be $40 million. In addition, Family Radio acquired Cumulus' WDVY (106.3 FM) in

text: Mount Kisco, New York

text: . The FCC approved the sale/station trade January 4, 2013, making 94.7 FM a sister station to Cumulus' two existing New York market stations,

text: WABC

text: and

text: WPLJ

text: . Four days later, on January 8, 2013, Cumulus completed the purchase of WFME. Family Radio programming on 94.7 FM ended at 3:40 p.m. on January 11, 2013; prior to signing off of the frequency, station manager Charlie Menut stated that the network's programming would be transferred to 106.3 FM, which became

text: the new WFME

text: on January 15, and that efforts to acquire an AM frequency that would cover the New York City area were being made. Two years later, in February 2015, Family Radio programming returned to the area via its acquisition of

text: WQEW

text: (1560 AM), a former

text: Radio Disney

text: outlet.

text: In Canada, the Canadian Radio-television and Telecommunications Commission maintains a comparative process in issuing permits, n-suring that a variety of programming is available in each area, and that as many groups as possible have access to free speech over radio waves.

text: In Canada, the

text: maintains a comparative process in issuing permits, n-suring that a variety of programming is available in each area, and that as many groups as possible have access to

text: free speech

text: over

text: radio waves

text: Between 1956–1965 Radio Free Scotland (RFS) broadcast through the PAL audio channel of BBC television (then on VHF) after God Save the Queen finished in the evening, and, later on, on 262 metres medium wave on the radio.

text: Between 1956–1965 Radio Free Scotland (RFS) broadcast through the PAL audio channel of

text: BBC

text: television

text: (then on VHF) after

text: God Save the Queen

text: finished in the evening, and, later on, on 262 metres

text: medium wave

text: on the

text: radio

text: The concept of refractive index is widely used within the full electromagnetic spectrum, from X-rays to radio waves. It can also be used with wave phenomena such as sound. In this case the speed of sound is used instead of that of light and a reference medium other than vacuum must be chosen.

text: The concept of refractive index is widely used within the full

text: electromagnetic spectrum

text: , from

text: X-ray

text: s to

text: radio wave

text: s. It can also be used with

text: wave

text: phenomena such as

text: sound

text: . In this case the speed of sound is used instead of that of light and a reference medium other than vacuum must be chosen.

text: All Canadian FM stations have an "–FM" suffix, except for low-power rebroadcasters which have semi-numeric "VF" call signs. Higher-power rebroadcasters are generally licensed under the call sign of the originating station, followed by a numeric suffix and, for FM re-broadcasters of an AM station, a "–FM" suffix. For example, CJBC-1-FM rebroadcasts CJBC (860 Toronto), whereas CJBC-FM-1 rebroadcasts CJBC-FM (90.3 Toronto). Some rebroadcasters, however, may have their own distinct call signs. Canadian television stations always use the "-TV" suffix, with the exception of those CBC-owned stations which have a call sign in the "CB-(-)T" format. Canadian digital transitional television undertakings have "-DT" suffixes, even where the base call sign is a CBC/Radio-Canada O&O in pattern "CB(insert third letter)T", "CB(insert third letter)ET" or "CB(insert third letter)FT" (respectively for English language or French language television). For instance, Ici Radio-Canada Télé's O&O CBOFT-DT would represent "CBC Ottawa Français Télévision - Digital Television". Canada does not use the "-LP" or "-CA" suffixes that are in use in the United States but makes limited use of "-SW" for privately owned shortwave radio stations.

text: All Canadian FM stations have an "–FM" suffix, except for low-power rebroadcasters which have semi-numeric "VF" call signs. Higher-power rebroadcasters are generally licensed under the call sign of the originating station, followed by a numeric suffix and, for FM re-broadcasters of an AM station, a "–FM" suffix. For example, CJBC-1-FM rebroadcasts

text: CJBC

text: (860 Toronto), whereas CJBC-FM-1 rebroadcasts

text: CJBC-FM

text: (90.3 Toronto). Some rebroadcasters, however, may have their own distinct call signs. Canadian television stations always use the "-TV" suffix, with the exception of those CBC-owned stations which have a call sign in the "CB-(-)T" format. Canadian

entity_name: Digital terrestrial television in Canada

text: digital transitional television

text: undertakings have "-DT" suffixes, even where the base call sign is a CBC/Radio-Canada O&O in pattern "CB(insert third letter)T", "CB(insert third letter)ET" or "CB(insert third letter)FT" (respectively for

text: English language

text: or

text: French language

text: television). For instance, Ici Radio-Canada Télé's O&O

text: CBOFT-DT

text: would represent "CBC Ottawa Français Télévision - Digital Television". Canada does not use the "-LP" or "-CA" suffixes that are in use in the United States but makes limited use of "-SW" for privately owned

text: shortwave radio

text: stations.

text: Nanaimo is also served by the Jim Pattison Group's CHWF-FM (The Wolf) and CKWV-FM (The Wave), as well as CHLY-FM, an independent community campus radio station and Vista Radio's CKAY-FM (Coast FM). CBC Radio One is heard over CBU from Vancouver, providing Nanaimo with local programming from Vancouver instead of from Victoria.

text: Nanaimo is also served by the

text: Jim Pattison Group

text: 's

text: CHWF-FM

text: (The Wolf) and

text: CKWV-FM

text: (The Wave), as well as

text: CHLY-FM

text: , an independent community

text: campus radio

text: station and

text: Vista Radio

text: 's

text: CKAY-FM

text: (Coast FM).

text: CBC Radio One

text: is heard over

text: CBU

text: from Vancouver, providing Nanaimo with local programming from Vancouver instead of from

text: Victoria

text: By the 1980s, AM radio was in severe decline. Top 40 radio had already migrated to the higher fidelity of FM, and the few remaining AM formats, particularly country music, were headed in the same direction or, in the case of formats such as MOR, falling out of favor entirely. Talk radio, not needing the high fidelity that music does, became an attractive format for AM radio station operators. However, in order to capitalize on this, operators needed compelling content.

text: By the 1980s,

text: AM radio

text: was in severe decline.

text: Top 40

text: radio had already migrated to the higher fidelity of

text: FM

text: , and the few remaining AM formats, particularly

text: country music

text: , were headed in the same direction or, in the case of formats such as

text: MOR

text: , falling out of favor entirely. Talk radio, not needing the high fidelity that music does, became an attractive format for AM radio station operators. However, in order to capitalize on this, operators needed compelling content.

text: Most commercial television stations are owned independently, but many are either affiliated with a television network or are owned-and-operated (O&O) by a television network. Another form a television station may take is non-commercial educational (NCE) and considered public broadcasting. To avoid concentration of media ownership of television stations, government regulations in most countries generally limit the ownership of television stations by television networks or other media operators, but these regulations vary considerably. Some countries have set up nationwide television networks, in which individual television stations act as mere repeaters of nationwide programs. In those countries, the local television station has no station identification and, from a consumer's point of view, there is no practical distinction between a network and a station, with only small regional changes in programming, such as local television news.

text: Most

text: commercial television

text: stations are owned independently, but many are either

text: affiliate

text: d with a

text: television network

text: or are

text: owned-and-operated

text: (O&O) by a television network. Another form a television station may take is

text: non-commercial educational

text: (NCE) and considered

text: public broadcasting

text: . To avoid

text: concentration of media ownership

text: of television stations, government regulations in most countries generally limit the ownership of television stations by television networks or other media operators, but these regulations vary considerably. Some countries have set up nationwide television networks, in which individual television stations act as mere

text: repeater

text: s of nationwide

text: programs

text: . In those countries, the local television station has no

text: station identification

text: and, from a consumer's point of view, there is no practical distinction between a network and a station, with only small regional changes in programming, such as local

text: television news

text: A radio telescope is a specialized antenna and radio receiver used to receive radio waves from astronomical radio sources in the sky in radio astronomy. Radio telescopes are the main observing instrument used in radio astronomy, which studies the radio frequency portion of the electromagnetic spectrum emitted by astronomical objects, just as optical telescopes are the main observing instrument used in traditional optical astronomy which studies the light wave portion of the spectrum coming from astronomical objects. Radio telescopes are typically large parabolic ("dish") antennas similar to those employed in tracking and communicating with satellites and space probes.  They may be used singly, or linked together electronically in an array.  Unlike optical telescopes, radio telescopes can be used in the daytime as well as at night.  Since astronomical radio sources such as stars, nebulas and galaxies are very far away, the radio waves coming from them are extremely weak, so radio telescopes require very large antennas to collect enough radio energy to study them, and extremely sensitive receiving equipment.  Radio observatories are preferentially located far from major centers of population to avoid electromagnetic interference (EMI) from radio, television, radar, motor vehicles, and other EMI emitting devices.

text: A radio telescope is a specialized

text: antenna

text: and

text: radio receiver

text: used to receive

text: radio wave

text: s from

text: astronomical radio source

text: s in the sky in

text: radio astronomy

text: . Radio telescopes are the main observing instrument used in radio astronomy, which studies the

text: radio frequency

text: portion of the

text: electromagnetic spectrum

text: emitted by astronomical objects, just as

text: optical telescope

text: s are the main observing instrument used in traditional

text: optical astronomy

text: which studies the

text: light wave

text: portion of the spectrum coming from astronomical objects. Radio telescopes are typically large

text: parabolic

text: ("dish") antennas similar to those employed in tracking and communicating with

text: satellite

text: s and space probes.  They may be used singly, or linked together electronically in an array.  Unlike optical telescopes, radio telescopes can be used in the daytime as well as at night.  Since astronomical radio sources such as

text: star

text: s,

text: nebula

text: s and

text: galaxies

text: are very far away, the radio waves coming from them are extremely weak, so radio telescopes require very large antennas to collect enough radio energy to study them, and extremely sensitive receiving equipment.  Radio

text: observatories

text: are preferentially located far from major centers of population to avoid

text: electromagnetic interference

text: (EMI) from radio,

text: television

text: radar

text: , motor vehicles, and other EMI emitting devices.

text: A television program () is a segment of content intended for broadcast on over-the-air, cable television, or Internet television, other than a commercial,  trailer, or any other segment of content not serving as attraction for viewership. It may be a single production, or more commonly, a series of related productions (also called a television series or a television show).

text: A television program () is a segment of content intended for broadcast on over-the-air, cable television, or

text: Internet television

text: , other than a

text: commercial

text: ,  trailer, or any other segment of content not serving as attraction for viewership. It may be a single production, or more commonly, a series of related productions (also called a television series or a television show).

text: Barron's work with Henry Rishbeth on radio wave propagation was pioneering in furthering the understanding of how radio waves were reflected at the ionospheric boundary.

text: Barron's work with

text: Henry Rishbeth

text: on radio wave propagation was pioneering in furthering the understanding of how radio waves were reflected at the ionospheric boundary.

text: Very low frequency or VLF is the radio frequencies (RF) in the range of 3 to 30 kHz. Since there is not much bandwidth in this band of the radio spectrum, only the very simplest signals are used, such as for radio navigation. Also known as the myriameter band or myriameter wave as the wavelengths range from ten to one myriameter (an obsolete metric unit equal to 10 kilometers).

text: Very low frequency or VLF is the radio frequencies (RF) in the range of 3 to 30 kHz. Since there is not much bandwidth in this band of the radio spectrum, only the very simplest signals are used, such as for radio navigation. Also known as the

text: myriameter

text: band or myriameter wave as the wavelengths range from ten to one myriameter (an obsolete metric unit equal to 10 kilometers).

text: The station began life as Pennine Radio which was part of the Yorkshire Radio Network, but when it split its AM and FM frequencies, the medium wave licence became Classic Gold. Following a take over it was then relaunched as Great Yorkshire Radio, and then Great Yorkshire Gold.

text: The station began life as

text: Pennine Radio

text: which was part of the

text: Yorkshire Radio Network

text: , but when it split its AM and FM frequencies, the medium wave licence became

text: Classic Gold

text: . Following a take over it was then relaunched as Great Yorkshire Radio, and then Great Yorkshire Gold.

text: The radio station was funded by the Student Union at the University of Essex, and changed identity to RED - 1404 AM in 2006. URE first broadcast on the 1 March 1971, on 301 metres medium wave (originally 998 kHz, later 999 kHz AM). It later broadcast on 963 kHz AM, 1404 kHz AM, 1602 kHz AM, and 87.7 MHz FM.

text: The radio station was funded by the

text: Student Union

text: at the University of Essex, and changed identity to

text: RED - 1404 AM

text: in 2006. URE first broadcast on the 1 March 1971, on 301 metres medium wave (originally 998 kHz, later 999 kHz AM). It later broadcast on 963 kHz AM, 1404 kHz AM, 1602 kHz AM, and 87.7 MHz FM.

text: Most materials of the type affecting radio wave transmission over NLOS links are intermediate: they are neither good insulators nor good conductors. Radio waves incident upon an obstruction comprising a thin intermediate material are partly reflected at both the incident and exit boundaries and partly absorbed, depending on the thickness. If the obstruction is thick enough the radio wave might be completely absorbed. Because of the absorption, these are often called lossy materials, although the degree of loss is usually extremely variable and often very dependent on the level of moisture present. They are often heterogeneous and comprise a mixture of materials with various degrees of conductor and insulator properties. Such examples are hills, valley sides, mountains (with substantial vegetation) and buildings constructed from stone, brick or concrete but without reinforced steel. The thicker they are the greater the loss. For example, a wall absorbs much less RF power from a normally incident wave than a building constructed from the same material.

text: In radio and telecommunication, a traveling-wave antenna is a class of antenna that use a traveling wave on a guiding structure as the main radiating mechanism.    Their distinguishing feature is that the radio-frequency current that generates the radio waves travels through the antenna in one direction.  This is in contrast to a resonant antenna, such as the monopole or dipole, in which the antenna acts as a resonator, with radio currents traveling in both directions, bouncing back and forth between the ends of the antenna.  An advantage of traveling wave antennas is that since they are nonresonant they often have a wider bandwidth than resonant antennas.  Common types of traveling wave antenna are the Beverage antenna and the rhombic antenna.

text: In

text: radio

text: and

text: telecommunication

text: , a traveling-wave antenna is a class of

text: antenna

text: that use a traveling wave on a guiding structure as the main radiating mechanism.    Their distinguishing feature is that the radio-frequency current that generates the radio waves travels through the antenna in one direction.  This is in contrast to a resonant antenna, such as the

text: monopole

text: or

text: dipole

text: , in which the antenna acts as a

text: resonator

text: , with radio currents traveling in both directions, bouncing back and forth between the ends of the antenna.  An advantage of traveling wave antennas is that since they are nonresonant they often have a wider

text: bandwidth

text: than resonant antennas.  Common types of traveling wave antenna are the

text: Beverage antenna

text: and the

text: rhombic antenna

text: The station first signed on the air on March 27, 1950. Originally broadcasting on VHF channel 9; it was the second television station to sign on in the Louisville market and the state of Kentucky (after NBC affiliate WAVE-TV, which signed on in November 1948). WHAS-TV was founded by the Bingham family, publishers of morning newspaper The Courier-Journal, afternoon newspaper The Louisville Times and operator of WHAS (840 AM), Louisville's oldest radio station. It operated from brand-new studios in the Courier-Journal/Times Building at 6th & Broadway, in downtown Louisville-even though WHAS-TV's construction permit (1946) was issued before WAVE-TV's (1947), the Bingham family waited until the new TV facility was finished to begin telecasting, 16 months after WAVE, who adapted an existing building at Preston and Broadway.The station originally operated as a primary CBS affiliate, owing to its sister radio station's longtime affiliation with the CBS Radio Network, with a secondary affiliation with ABC.  It moved to VHF channel 11 on February 7, 1953, one of several channel shifts resulting from the Federal Communications Commission's 1952 Sixth Report and Order. Under the same decree, WAVE-TV relocated from channel 5 to channel 3.

text: The station first signed on the air on March 27, 1950. Originally broadcasting on VHF channel 9; it was the second television station to sign on in the Louisville market and the state of Kentucky (after

text: NBC

text: affiliate

text: WAVE-TV

text: , which signed on in November 1948). WHAS-TV was founded by the Bingham family, publishers of morning newspaper

text: The Courier-Journal

text: , afternoon newspaper

text: The Louisville Times

text: and operator of

text: WHAS

text: (840 AM), Louisville's oldest radio station. It operated from brand-new studios in the Courier-Journal/Times Building at 6th & Broadway, in downtown Louisville-even though WHAS-TV's construction permit (1946) was issued before WAVE-TV's (1947), the Bingham family waited until the new TV facility was finished to begin telecasting, 16 months after WAVE, who adapted an existing building at Preston and Broadway.The station originally operated as a primary

text: CBS

text: affiliate, owing to its sister radio station's longtime affiliation with the

text: CBS Radio Network

text: , with a secondary affiliation with ABC.  It moved to VHF channel 11 on February 7, 1953, one of several channel shifts resulting from the

text: Federal Communications Commission

text: 's 1952 Sixth Report and Order. Under the same decree, WAVE-TV relocated from channel 5 to channel 3.

text: Curtain arrays are a class of large  multielement directional wire  radio transmitting antennas, used in the shortwave radio bands.   They are a type of reflective array antenna, consisting of multiple wire dipole antennas,  suspended in a plane, often in front of a "curtain" reflector made of a flat vertical screen of many long parallel wires. These are suspended by support wires strung between pairs of tall steel towers, up to  high. They are used for long-distance skywave (or skip) transmission; they transmit a beam of radio waves at a shallow angle into the sky, which is reflected by the ionosphere back to Earth beyond the horizon. Curtain antennas are mostly used by international short wave radio stations to broadcast to large areas at transcontinental distances.

text: Curtain arrays are a class of large  multielement

text: directional

text: wire  radio transmitting

text: antenna

text: s, used in the

text: shortwave

text: radio bands.   They are a type of

text: reflective array antenna

text: , consisting of multiple wire

text: dipole antenna

text: s,  suspended in a plane, often in front of a "curtain" reflector made of a flat vertical screen of many long parallel wires. These are suspended by support wires strung between pairs of tall steel towers, up to  high. They are used for long-distance

text: skywave

text: (or skip) transmission; they transmit a beam of radio waves at a shallow angle into the sky, which is reflected by the

text: ionosphere

text: back to Earth beyond the horizon. Curtain antennas are mostly used by international short wave

text: radio station

text: s to broadcast to large areas at transcontinental distances.

text: In astronomy, interplanetary scintillation refers to random fluctuations in the intensity of radio waves of celestial origin, on the timescale of a few seconds. It is analogous to the twinkling one sees looking at stars in the sky at night, but in the radio part of the electromagnetic spectrum rather than the visible one. Interplanetary scintillation is the result of radio waves traveling through fluctuations in the density of the electron and protons that make up the solar wind.

text: In

text: astronomy

text: , interplanetary scintillation refers to random fluctuations in the intensity of

text: radio wave

text: s of

text: celestial

text: origin, on the timescale of a few seconds. It is analogous to the

text: twinkling

text: one sees looking at

text: star

text: s in the

text: sky

text: at night, but in the radio part of the

text: electromagnetic spectrum

text: rather than the

text: visible one

text: . Interplanetary scintillation is the result of radio waves traveling through fluctuations in the density of the

text: electron

text: and

text: proton

text: s that make up the

text: solar wind

text: Today, Radio Marti broadcasts a 24-hour radio program over short-wave transmitters in Delano, California, and Greenville, North Carolina, and a medium-wave transmitter in Marathon, Florida (GC: ). Its studios are located in Miami, Florida. Cuba jams both the medium-wave and shortwave signals, but the shortwave program is heard in Canada and throughout Central America and South America. On occasion, the medium-wave transmitter at 1180 kHz can be heard as far north as Washington, D.C.

text: Today, Radio Marti broadcasts a 24-hour radio program over

text: short-wave

text: transmitters in

text: Delano

text: California

text: , and

text: Greenville

text: North Carolina

text: , and a

text: medium-wave

text: transmitter in

text: Marathon

text: , Florida (GC: ). Its studios are located in Miami, Florida. Cuba jams both the medium-wave and shortwave signals, but the shortwave program is heard in

text: Canada

text: and throughout

text: Central America

text: and

text: South America

text: . On occasion, the medium-wave transmitter at 1180 kHz can be heard as far north as

text: Washington, D.C.

text: Most of Des Moines' commercial radio stations are owned by one of four companies. iHeartMedia owns five radio stations in the area, including WHO 1040 am, a 50,000-watt AM news/talk station that has the highest ratings in the area and once employed future President Ronald Reagan as a sportscaster. In addition to WHO, iHeartMedia owns KDRB 100.3 FM (adult hits), KKDM 107.5 FM (contemporary hits), KDXA 106.3 FM (alternative rock), and KXNO 1460 am (sports radio). (They also own news/talk station KASI 1430 am and hot adult contemporary station KCYZ 105.1 FM, both of which broadcast from Ames.) Cumulus Media owns five stations that broadcast from facilities in Urbandale: KBGG 1700 am (sports), KGGO 94.9 FM (classic rock), KHKI 97.3 FM (country music), KJJY 92.5 FM (country music), and KWQW 98.3 FM (classic hip hop). Saga Communications owns seven stations in the area: KAZR 103.3 FM (rock), KIOA 93.3 FM (oldies), KIOA-HD2 99.9FM & 93.3 HD2 (Rhythmic Top 40), KMYR 104.1 FM (soft adult contemporary), KPSZ 940 am (contemporary Christian music), KRNT 1350 am (ESPN Radio), and KSTZ 102.5 FM (adult contemporary hits). Other stations in the Des Moines area include religious stations KNWI 107.1 FM, KWKY 1150 am, and KPUL 101.7 FM.

text: Most of Des Moines' commercial radio stations are owned by one of four companies.

text: iHeartMedia

text: owns five radio stations in the area, including

text: WHO

text: 1040 am, a 50,000-watt AM

text: news/talk

text: station that has the highest ratings in the area and once employed future President

text: Ronald Reagan

text: as a sportscaster. In addition to WHO, iHeartMedia owns

text: KDRB

text: 100.3 FM (

text: adult hits

text: KKDM

text: 107.5 FM (

text: contemporary hits

text: KDXA

text: 106.3 FM (

text: alternative rock

text: ), and

text: KXNO

text: 1460 am (

text: sports radio

text: ). (They also own news/talk station

text: KASI

text: 1430 am and

text: hot adult contemporary

text: station

text: KCYZ

text: 105.1 FM, both of which broadcast from

text: Ames

text: Cumulus Media

text: owns five stations that broadcast from facilities in

text: Urbandale

text: KBGG

text: 1700 am (sports),

text: KGGO

text: 94.9 FM (

text: classic rock

text: KHKI

text: 97.3 FM (

text: country music

text: KJJY

text: 92.5 FM (country music), and

text: KWQW

text: 98.3 FM (

text: classic hip hop

text: ). Saga Communications owns seven stations in the area:

text: KAZR

text: 103.3 FM (

text: rock

text: KIOA

text: 93.3 FM (

text: oldies

text: 99.9FM & 93.3 HD2 (

text: Rhythmic Top 40

text: KMYR

text: 104.1 FM (

text: soft adult contemporary

text: KPSZ

text: 940 am (

text: contemporary Christian music

text: KRNT

text: 1350 am (

text: ESPN Radio

text: ), and

text: KSTZ

text: 102.5 FM (

text: adult contemporary hits

text: ). Other stations in the Des Moines area include religious stations

text: KNWI

text: 107.1 FM,

text: KWKY

text: 1150 am, and

text: KPUL

text: 101.7 FM.

text: The term wave is often intuitively understood as referring to a transport of spatial disturbances that are generally not accompanied by a motion of the medium occupying this space as a whole.  In a wave, the energy of a vibration is moving away from the source in the form of a disturbance within the surrounding medium . However, this motion is problematic for a standing wave (for example, a wave on a string), where energy is moving in both directions equally, or for electromagnetic (e.g., light) waves in a vacuum, where the concept of medium does not apply and interaction with a target is the key to wave detection and practical applications. There are water waves on the ocean surface; gamma waves and light waves emitted by the Sun; microwaves used in microwave ovens and in radar equipment; radio waves broadcast by radio stations; and sound waves generated by radio receivers, telephone handsets and living creatures (as voices), to mention only a few wave phenomena.

text: The term wave is often intuitively understood as referring to a transport of spatial disturbances that are generally not accompanied by a motion of the medium occupying this space as a whole.  In a wave, the

text: energy

text: of a

text: vibration

text: is moving away from the source in the form of a disturbance within the surrounding medium . However, this motion is problematic for a

text: standing wave

text: (for example, a wave on a string), where

text: energy

text: is moving in both directions equally, or for electromagnetic (e.g., light) waves in a

text: vacuum

text: , where the concept of medium does not apply and interaction with a target is the key to wave detection and practical applications. There are

text: water waves

text: on the ocean surface;

text: gamma waves

text: and

text: light waves

text: emitted by the Sun;

text: microwaves

text: used in microwave ovens and in

text: radar

text: equipment;

text: radio waves

text: broadcast by radio stations; and

text: sound waves

text: generated by radio receivers, telephone handsets and living creatures (as voices), to mention only a few wave phenomena.

text: For all radio transmissions above 30 MHz (which are not reflected by the ionosphere) there is a possibility of meteor reflection of the radio signal. Meteors leave a trail of ionised particles and electrons as they pass through the upper atmosphere (a process called ablation) which reflect transmission radio waves which would usually flow into space. These reflected waves are from transmitters which are below the horizon of the received meteor reflection.  In Europe this means the brief scattered wave may carry a foreign voice which can interfere with radio receivers.  Meteor reflected radio waves last between 0.05 seconds and 1 second, depending on the size of the meteor.

text: XEW-AM is a radio station in Mexico City, Mexico, broadcasting on the AM frequency of 900 kHz; it is branded as W-Radio. XEW-AM serves as the originating station for other "W-Radio" stations around Mexico that carry some of its programs.  The programming on XEW-AM is also simulcast on Mexico City FM radio station 96.9 XEW-FM.

text: XEW-AM is a

text: radio station

text: in

text: Mexico City

text: Mexico

text: , broadcasting on the

text: AM

text: frequency of

text: 900 kHz

text: ; it is branded as W-Radio. XEW-AM serves as the originating station for other "W-Radio" stations around Mexico that carry some of its programs.  The programming on XEW-AM is also simulcast on Mexico City FM radio station 96.9 XEW-FM.

text: To prevent interference between different users, the artificial generation and use of radio waves is strictly regulated by law, coordinated by an international body called the International Telecommunications Union (ITU), which defines radio waves as "electromagnetic waves of frequencies arbitrarily lower than 3 000 GHz, propagated in space without artificial guide". The radio spectrum is divided into a number of radio bands on the basis of frequency, allocated to different uses.

text: To prevent

text: interference

text: between different users, the artificial generation and use of radio waves is strictly regulated by law, coordinated by an international body called the

text: International Telecommunications Union

text: (ITU), which defines radio waves as "

text: electromagnetic wave

text: s of

text: frequencies

text: arbitrarily lower than 3 000

text: GHz

text: , propagated in space without artificial guide". The

text: radio spectrum

text: is divided into a number of

text: radio band

text: s on the basis of frequency, allocated to different uses.

text: In 1980, AM radio stations captured 77 percent of the Mexican radio audience. However, in the five years that followed, the tables turned in favor of FM, which had a 64.9 percent market share as opposed to AM's 35.1 percent. The FM band's stereo capabilities and the increased prevalence of portable radios with improved sound quality would lead to the development of AM as a specialized talk radio band, with music radio stations migrating to FM.

text: NCN runs three radio services: Fresh 100.1 FM, re-branded in 2012, formerly Radio Roraima (formerly Channel 1), which uses the radio frequency 760 AM (760 kilohertz on the medium wave band; no longer broadcasting); Voice of Guyana (formerly Channel 2), which uses the radio frequency 560 AM (560 kilohertz on the medium wave band); and an 102.1FM service — Hot FM — which uses the radio frequency 98.1 FM. All three services are controlled by the government.

text: NCN runs three radio services: Fresh 100.1 FM, re-branded in 2012, formerly Radio Roraima (formerly Channel 1), which uses the radio frequency 760 AM (760 kilohertz on the

text: medium wave

text: band; no longer broadcasting); Voice of Guyana (formerly Channel 2), which uses the radio frequency 560 AM (560 kilohertz on the medium wave band); and an

text: service — Hot FM — which uses the radio frequency 98.1 FM. All three services are controlled by the government.

text: FM broadcasting in the USA began in the 1930s. Although many broadcast radio stations had already been established in the AM frequency range, the use of FM radio offered higher sound quality. However until the 1970s, FM broadcast frequencies were primarily seen as investments in the future, with most of the self-supporting commercial stations simulcasting with AM stations. Few automobiles in the U.S. were equipped to receive FM signals until the early 1970s.

text: FM broadcasting in the USA

text: began in the 1930s. Although many broadcast radio stations had already been established in the

text: AM frequency range

text: , the use of

text: FM radio

text: offered higher sound quality. However until the 1970s, FM broadcast frequencies were primarily seen as investments in the future, with most of the self-supporting commercial stations

text: simulcast

text: ing with AM stations. Few

text: automobile

text: s in the U.S. were equipped to receive FM signals until the early 1970s.

text: The radio stations in San Diego include nationwide broadcaster, Clear Channel Communications; CBS Radio, Midwest Television, Lincoln Financial Media, Finest City Broadcasting, and many other smaller stations and networks. Stations include: KOGO AM 600, KFMB AM 760, KCEO AM 1000, KCBQ AM 1170, K-Praise, KLSD AM 1360 Air America, KFSD 1450 AM, KPBS-FM 89.5, Channel 933, Star 94.1, FM 94/9, FM News and Talk 95.7, Q96 96.1, KyXy 96.5, Free Radio San Diego (AKA Pirate Radio San Diego) 96.9FM FRSD, KSON 97.3/92.1, KXSN 98.1, Jack-FM 100.7, 101.5 KGB-FM, KLVJ 102.1, Rock 105.3, and another Pirate Radio station at 106.9FM, as well as a number of local Spanish-language radio stations.

text: The radio stations in San Diego include nationwide broadcaster,

text: Clear Channel Communications

text: CBS Radio

text: , Midwest Television,

text: Lincoln Financial Media

text: , Finest City Broadcasting, and many other smaller stations and networks. Stations include:

text: KOGO AM 600

text: KFMB AM 760

text: KCEO AM 1000

text: KCBQ AM 1170

text: K-Praise

text: KLSD AM 1360

text: Air America

text: KFSD 1450 AM

text: KPBS-FM

text: Channel 933

text: Star 94.1

text: FM 94/9

text: FM News and Talk 95.7

text: KyXy

text: Free Radio San Diego

text: (AKA

text: Pirate Radio

text: San Diego) 96.9FM FRSD,

text: KSON

text: KXSN

text: Jack-FM 100.7

text: , 101.5

text: KGB-FM

text: KLVJ

text: Rock 105.3

text: , and another

text: Pirate Radio

text: station at 106.9FM, as well as a number of local Spanish-language radio stations.

text: If unobstructed, radio waves will travel in a straight line from the transmitter to the receiver. But if there are reflective surfaces along the path, such as bodies of water or smooth terrain, the radio waves reflecting off those surfaces may arrive either out of phase or in phase with the signals that travel directly to the receiver.  Waves that reflect off surfaces within  an odd Fresnel zone are out of phase with the direct-path wave and reduce the power of the received signal.  Waves that reflect off surfaces within an even Fresnel zone are in phase with the direct-path wave and can enhance the power of the received signal. Sometimes this results in the counter-intuitive finding that reducing the height of an antenna increases the signal-to-noise ratio. (This conflicts with many sources, which state that the direct path is zone 1; therefore, obstructing odd-numbered zones can have a constructive effect and vice-versa. For example, obstructing zone 2 would deflect some of it into the direct zone 1, thus adding destructively and weakening the signal.)

text: If unobstructed, radio waves will travel in a straight line from the transmitter to the receiver. But if there are reflective surfaces along the path, such as bodies of water or smooth terrain, the radio waves reflecting off those surfaces may arrive either out of phase or in phase with the signals that travel directly to the receiver.  Waves that reflect off surfaces within  an odd Fresnel zone are out of phase with the direct-path wave and reduce the power of the received signal.  Waves that reflect off surfaces within an even Fresnel zone are in phase with the direct-path wave and can enhance the power of the received signal. Sometimes this results in the counter-intuitive finding that reducing the height of an antenna increases the

text: signal-to-noise ratio

text: . (This conflicts with many sources, which state that the direct path is zone 1; therefore, obstructing odd-numbered zones can have a constructive effect and vice-versa. For example, obstructing zone 2 would deflect some of it into the direct zone 1, thus adding destructively and weakening the signal.)

text: Plasmas can have a wide range of values in both temperature and density; plasma temperatures range from close to absolute zero and to well beyond 10 kelvins (for comparison, tungsten melts at 3700 kelvins), and plasma may contain less than one particle per cubic metre, or be denser than lead. Electron temperature is usually expressed as electronvolt (eV), and 1 eV is equivalent to 11,604 K. Common plasmas temperature and density in fluorescent light tubes and semiconductor manufacturing processes are around several eV and 10per cm. For a wide range of parameters and frequencies, plasma is electrically conductive, and its response to low-frequency electromagnetic waves is similar to that of a metal: a plasma simply reflects incident low-frequency radiation. Low-frequency means it is lower than the characteristic electron plasma frequency. The use of plasmas to control the reflected electromagnetic radiation from an object (Plasma stealth) is feasible at suitable frequency where the conductivity of the plasma allows it to interact strongly with the incoming radio wave, and the wave can either be absorbed and converted into thermal energy, or reflected, or transmitted depending on the relationship between the radio wave frequency and the characteristic plasma frequency. If the frequency of the radio wave is lower than the plasma frequency, it is reflected. if it is higher, it transmit. If these two are equal, then resonance occurs. There are also another mechanism where reflection can be reduced. If the electromagnetic wave passes through the plasma, and is reflected by the metal, and the reflected wave and incoming wave are roughly equal in power, then they may form two phasors. When these two phasors are of opposite phase they can cancel each other out. In order to obtain substantial attenuation of radar signal, the plasma slab needs adequate thickness and density.

text: Plasmas can have a wide range of values in both temperature and density; plasma temperatures range from close to absolute zero and to well beyond 10

text: kelvin

text: In 1990 the plant was taken over by the Deutsche Telekom AG. At first it was planned to shut down the facility: so the cage aerial at the 359.7 metres high main mast was dismantled and the transmitting power of the long wave transmitter was reduced occasionally to 100 kilowatts. In the second half of the 1990s a reorientation occurred. The long wave transmitter was modernized and the main antenna tower received a new cage aerial. Also the transmitting power of the long wave transmitter was increased again to 500 kW. In the year 2000 a 120 metre high, guyed, grounded mast of lattice steel carrying a cage aerial for medium wave was built. He took over the function of the former Transmitter Berlin-Koepenick and served apart from the spreading of the program of MEGARADIO also for transmitting of programs of the Voice of Russia, partly in the Simulcast mode. The long wave transmitter changed over on 29 August 2005 as first German large transmitter to Digital Radio Mondiale. The long wave transmitter ceased operation on December 31, 2014 as part of the general shutdown in Germany of AM radio services to the public. The mast continues to support VHF radio antennas providing FM broadcast services.

text: In

text: the plant was taken over by the

text: Deutsche Telekom AG

text: . At first it was planned to shut down the facility: so the cage aerial at the 359.7 metres high main mast was dismantled and the transmitting power of the long wave transmitter was reduced occasionally to 100 kilowatts. In the second half of the 1990s a reorientation occurred. The long wave transmitter was modernized and the main antenna tower received a new cage aerial. Also the transmitting power of the long wave transmitter was increased again to 500 kW. In the year 2000 a 120 metre high, guyed, grounded mast of lattice steel carrying a cage aerial for

text: medium wave

text: was built. He took over the function of the former

text: Transmitter Berlin-Koepenick

text: and served apart from the spreading of the program of

text: MEGARADIO

text: also for transmitting of programs of the

text: Voice of Russia

text: , partly in the

text: Simulcast

text: mode. The long wave transmitter changed over on 29 August 2005 as first German large transmitter to

text: Digital Radio Mondiale

text: . The long wave transmitter ceased operation on December 31, 2014 as part of the general shutdown in Germany of AM radio services to the public. The mast continues to support VHF radio antennas providing FM broadcast services.

text: By the early 1990s, Egypt had only 4 FM stations in Greater Cairo (2 in Alexandria), but the number increased to 6 in Greater Cairo (4 in Alexandria) by the end of the decade. The increase in the number was merely a rebroadcast of the already AM radio stations. In 2000, AM stations (on the medium wave band) started a phase of simulcasting to FM band, as of 2013, only one or two stations broadcast on AM without FM simulcasts.

text: By the early 1990s, Egypt had only 4 FM stations in

text: Greater Cairo

text: (2 in

text: Alexandria

text: ), but the number increased to 6 in Greater Cairo (4 in Alexandria) by the end of the decade. The increase in the number was merely a rebroadcast of the already AM radio stations. In 2000,

text: AM

text: stations (on the

text: medium wave

text: band) started a phase of simulcasting to

text: FM

text: band, as of 2013, only one or two stations broadcast on AM without FM simulcasts.

text: Spectroscopy can detect a much wider region of the EM spectrum than the visible range of 400 nm to 700 nm. A common laboratory spectroscope can detect wavelengths from 2 nm to 2500 nm. Detailed information about the physical properties of objects, gases, or even stars can be obtained from this type of device. Spectroscopes are widely used in astrophysics. For example, many hydrogen atoms emit a radio wave photon that has a wavelength of 21.12 cm. Also, frequencies of 30 Hz and below can be produced by and are important in the study of certain stellar nebulae and frequencies as high as  have been detected from astrophysical sources.

text: Spectroscopy

text: can detect a much wider region of the EM spectrum than the visible range of 400 nm to 700 nm. A common laboratory spectroscope can detect wavelengths from 2 nm to 2500 nm. Detailed information about the physical properties of objects, gases, or even stars can be obtained from this type of device. Spectroscopes are widely used in

text: astrophysics

text: . For example, many

text: hydrogen

text: atom

text: s

text: emit

text: a

text: radio wave

text: photon that has a wavelength of 21.12 cm. Also, frequencies of 30

text: Hz

text: and below can be produced by and are important in the study of certain stellar nebulae and frequencies as high as  have been detected from astrophysical sources.

text: In December 2012 the company rebranded itself as Wave to emphasize its broadened spectrum of services.

text: Waves are usually described by variations in some parameter through space and time—for example, height in a water wave, pressure in a sound wave, or the electromagnetic field in a light wave. The value of this parameter is called the amplitude of the wave, and the wave itself is a function specifying the amplitude at each point.

text: Waves are usually described by variations in some parameter through space and time—for example, height in a water wave,

text: pressure

text: in a sound wave, or the

text: electromagnetic field

text: in a light wave. The value of this parameter is called the

text: amplitude

text: of the wave, and the wave itself is a

text: function

text: specifying the amplitude at each point.

text: Subpart C deals with devices that are specifically designed to produce coherent radio waves, such as small transmitters.  Specific to broadcasting, 15.239 deals with the FM band, while 15.221 (and 15.219) deal with the AM band.

text: Subpart C deals with devices that are specifically designed to produce coherent radio waves, such as small

text: transmitter

text: s.  Specific to

text: broadcasting

text: , 15.239 deals with the FM band, while 15.221 (and 15.219) deal with the AM band.

text: Radio Nepal () is the state-owned Radio broadcasting organisation of Nepal, which was established on 2 April 1951. Initially, the transmission lasted for 4 hours and 30 minutes through a 250 Watt short-wave transmitter. Over the years, Radio Nepal has strengthened its institutional capacity considerably and diversified itself in terms of programme format, technical efficiency and coverage. Radio Nepal airs programmes on short wave medium wave (AM) and FM frequencies.

text: Radio Nepal () is the state-owned Radio broadcasting organisation of

text: Nepal

text: , which was established on 2 April 1951. Initially, the transmission lasted for 4 hours and 30 minutes through a 250 Watt short-wave transmitter. Over the years, Radio Nepal has strengthened its institutional capacity considerably and diversified itself in terms of programme format, technical efficiency and coverage. Radio Nepal airs programmes on

text: short wave

text: medium wave

text: AM

text: ) and

text: FM

text: frequencies.

text: The next higher part of the radio electromagnetic spectrum, where the frequencies are above 30 GHz and below 100 GHz, are called "millimeter waves" because their wavelengths are conveniently measured in millimeters, and their wavelengths range from 10 mm down to 3.0 mm. Radio waves in this band are usually strongly attenuated by the Earthly atmosphere and particles contained in it, especially during wet weather. Also, in wide band of frequencies around 60 GHz, the radio waves are strongly attenuated by molecular oxygen in the atmosphere. The electronic technologies needed in the millimeter wave band are also much more difficult to utilize than those of the microwave band

text: The next higher part of the radio

text: electromagnetic spectrum

text: , where the frequencies are above 30 GHz and below 100 GHz, are called "

text: millimeter wave

text: s" because their wavelengths are conveniently measured in millimeters, and their wavelengths range from 10 mm down to 3.0 mm. Radio waves in this band are usually strongly

text: attenuate

text: d by the

text: Earthly atmosphere

text: and particles contained in it, especially during wet weather. Also, in wide band of frequencies around 60 GHz, the radio waves are strongly attenuated by

text: molecular oxygen

text: in the atmosphere. The electronic technologies needed in the millimeter wave band are also much more difficult to utilize than those of the microwave band

text: All Mexican radio stations within 320 km of the U.S. border are allowed to transmit their programs on the AM and FM bands utilizing HD Radio technology.  Approximately six Mexican AM and FM stations are already operating with HD Radio technology along Mexico’s border area with the US.  Grupo Imagen commenced HD Radio transmissions on XHDL-FM and XEDA-FM as well as Instituto Mexicano de la Radio on XHIMR-FM, XHIMER-FM and XHOF-FM in Mexico City in June 2012.

text: All Mexican radio stations

text: within 320 km of the U.S. border

text: are allowed to transmit their programs on the AM and FM bands utilizing HD Radio technology.  Approximately six Mexican AM and FM stations are already operating with HD Radio technology along Mexico’s border area with the US.  Grupo Imagen commenced HD Radio transmissions on XHDL-FM and XEDA-FM as well as Instituto Mexicano de la Radio on XHIMR-FM, XHIMER-FM and XHOF-FM in Mexico City in June 2012.

text: AM detectors cannot demodulate  FM and PM signals because both have a constant amplitude.  However an AM radio may detect the sound of an FM broadcast by the phenomenon of slope detection which occurs when the radio is tuned slightly above or below the nominal broadcast frequency. Frequency variation on one sloping side of the radio tuning curve gives the amplified signal a corresponding local amplitude variation, to which the AM detector is sensitive. Slope detection gives inferior distortion and noise rejection compared to the following dedicated FM detectors that are normally used.

text: AM detectors cannot demodulate

text: FM

text: and

text: PM

text: signals because both have a

text: constant amplitude

text: .  However an AM radio may detect the sound of an FM broadcast by the phenomenon of slope detection which occurs when the radio is tuned slightly above or below the nominal broadcast frequency. Frequency variation on one sloping side of the radio tuning curve gives the amplified signal a corresponding local amplitude variation, to which the AM detector is sensitive. Slope detection gives inferior distortion and noise rejection compared to the following dedicated FM detectors that are normally used.

text: It is also used for FM radio transmission of local radio stations BBC Radio London, Radio X, Capital Xtra and Absolute Radio, and a low-powered relay of the four BBC national FM services and Classic FM. It also has medium wave transmitters on 558 kHz (Spectrum Radio), 720 kHz (BBC Radio 4) and 1035 kHz (Kismat Radio). Since the tower is grounded, a wire aerial spun close to it is used for the MW services.

text: It is also used for

text: FM

text: radio transmission of local radio stations

text: BBC Radio London

text: Radio X

text: Capital Xtra

text: and

text: Absolute Radio

text: , and a low-powered relay of the four BBC national FM services and

text: Classic FM

text: . It also has

text: medium wave

text: transmitters on 558

text: kHz

text: Spectrum Radio

text: ), 720 kHz (

text: BBC Radio 4

text: ) and 1035 kHz (

text: Kismat Radio

text: ). Since the tower is grounded, a wire aerial spun close to it is used for the

text: MW

text: services.

text: In 1984 the original Bose Wave system, called the Acoustic Wave Music System (AW-1), was Bose's first-ever tabletop radio. It uses two 2 inch tweeters, and a four inch woofer (which is the only speaker utilizing the Wave Guide), a cassette player, and an AM/FM radio into a mid-sized tabletop stereo system. In 1992 that Bose replaced the cassette player with a CD player (the CD2000), but Bose continued to sell a cassette player version (the CS2010) as an alternative to the CD version until the Acoustic Wave Music System v3 (CD3000) replaced both of them in 1996.

text: In 1984 the original Bose Wave system, called the Acoustic Wave Music System (AW-1), was Bose's first-ever tabletop

text: radio

text: . It uses two 2 inch

text: tweeter

text: s, and a four inch

text: woofer

text: (which is the only speaker utilizing the

text: Wave Guide

text: ), a

text: cassette player

text: , and an

text: AM

text: FM

text: radio into a mid-sized tabletop stereo system. In 1992 that Bose replaced the cassette player with a

text: CD player

text: (the CD2000), but Bose continued to sell a cassette player version (the CS2010) as an alternative to the CD version until the Acoustic Wave Music System v3 (CD3000) replaced both of them in 1996.

text: the differential operators.According to Vakhitov–Kolokolov stability criterion,when k > 2, the spectrum of A has positive point eigenvalues, so that the linearized equation is linearly (exponentially) unstable; for 0 < k ≤ 2, the spectrum of A is purely imaginary, so that the corresponding solitary waves are linearly stable.

text: the

text: differential operators

text: .According to

text: Vakhitov–Kolokolov stability criterion

text: ,when k > 2, the spectrum of A has positive point eigenvalues, so that the linearized equation is linearly (exponentially) unstable; for 0 < k ≤ 2, the spectrum of A is purely imaginary, so that the corresponding solitary waves are linearly stable.

text: which is a function of a wave height spectrum

text: The transfer of energy between the wind blowing over the surface of an ocean and the ocean's upper layer is an important element in wave dynamics.  The spectral wave transport equation is used to describe the change in wave spectrum over changing topography.  It simulates wave generation, wave movement (propagation within a fluid), wave shoaling, refraction, energy transfer between waves, and wave dissipation.  Since surface winds are the primary forcing mechanism in the spectral wave transport equation, ocean wave models use information produced by numerical weather prediction models as inputs to determine how much energy is transferred from the atmosphere into the layer at the surface of the ocean. Along with dissipation of energy through whitecaps and resonance between waves, surface winds from numerical weather models allow for more accurate predictions of the state of the sea surface.<ref name="Bender">{{cite journal|author=Leslie C. Bender|title=Modification of the Physics and Numerics in a Third-Generation Ocean Wave Model|journal=Journal of Atmospheric and Oceanic Technology|date=January 1996|volume=13|issue=3|page=726|doi=10.1175/1520-0426(1996)013

text: spectral wave transport equation

text: wave shoaling

text: refraction

text: , energy transfer between waves, and wave dissipation.  Since surface winds are the primary forcing mechanism in the spectral wave transport equation, ocean wave models use information produced by numerical weather prediction models as inputs to determine how much energy is transferred from the atmosphere into the layer at the surface of the ocean. Along with dissipation of energy through whitecaps and

text: resonance

text: between waves, surface winds from numerical weather models allow for more accurate predictions of the state of the sea surface.<ref name="Bender">{{cite journal|author=Leslie C. Bender|title=Modification of the Physics and Numerics in a Third-Generation Ocean Wave Model|journal=

text: |date=January 1996|volume=13|issue=3|page=726|doi=10.1175/1520-0426(1996)013

text: Transmission of radio and television programs from a radio or television station to home receivers by radio waves is referred to as "over the air" (OTA) or terrestrial broadcasting and in most countries requires a broadcasting license.  Transmissions using a wire or cable, like cable television (which also retransmits OTA stations with their consent), are also considered broadcasts, but do not necessarily require a license (though in some countries, a license is required).  In the 2000s, transmissions of television and radio programs via streaming digital technology have increasingly been referred to as broadcasting as well, though strictly speaking this is incorrect.

text: Transmission of radio and television programs from a radio or television station to home receivers by

text: radio wave

text: s is referred to as "over the air" (OTA) or

text: terrestrial

text: broadcasting and in most countries requires a

text: broadcasting license

text: .  Transmissions using a wire or cable, like

text: cable television

text: (which also retransmits OTA stations with their

text: consent

text: ), are also considered broadcasts, but do not necessarily require a license (though in some countries, a license is required).  In the 2000s, transmissions of television and radio programs via

text: streaming

text: digital technology have increasingly been referred to as broadcasting as well, though strictly speaking this is incorrect.

text: Commercial radio stations broadcasting to the city include The Breeze, previously The Saint and currently broadcasting Hot adult contemporary music, Capital, previously Power FM and Galaxy and broadcasting popular music, Wave 105 and Heart Hampshire, the latter previously Ocean FM and both broadcasting adult contemporary music, and 106 Jack FM (www.jackradio.com), previously The Coast 106. In addition, Southampton University has a radio station called SURGE, broadcasting on AM band as well as through the web.

text: Commercial radio stations broadcasting to the city include

text: The Breeze

text: , previously The Saint and currently broadcasting

text: Hot adult contemporary

text: music,

text: Capital

text: , previously Power FM and Galaxy and broadcasting popular music,

text: Wave 105

text: and

text: Heart Hampshire

text: , the latter previously Ocean FM and both broadcasting

text: adult contemporary music

text: , and 106 Jack FM (www.jackradio.com), previously The Coast 106. In addition, Southampton University has a radio station called

text: SURGE

text: , broadcasting on AM band as well as through the web.

text: The antenna converts the energy in the electromagnetic radio waves to an alternating electric current in the antenna, which is connected to the tuning coil. Since in a crystal radio all the power comes from the antenna, it is important that the antenna collect as much power from the radio wave as possible. The larger an antenna, the more power it can intercept. Antennas of the type commonly used with crystal sets are most effective when their length is close to a multiple of a quarter-wavelength of the radio waves they are receiving. Since the length of the waves used with crystal radios is very long (AM broadcast band waves are 182-566 m or 597–1857 ft. long) the antenna is made as long as possible, from a long wire, in contrast to the whip antennas or ferrite loopstick antennas used in modern radios.

text: The antenna converts the energy in the electromagnetic

text: radio wave

text: s to an

text: alternating

text: electric current

text: in the antenna, which is connected to the tuning coil. Since in a crystal radio all the power comes from the antenna, it is important that the antenna collect as much power from the radio wave as possible. The larger an antenna, the more power it can intercept. Antennas of the type commonly used with crystal sets are most effective when their length is close to a multiple of a quarter-

text: wavelength

text: of the radio waves they are receiving. Since the length of the waves used with crystal radios is very long (

text: AM broadcast

text: band waves are 182-566

text: m

text: or 597–1857 ft. long) the antenna is made as long as possible, from a

text: long wire

text: , in contrast to the

text: whip antenna

text: s or ferrite

text: loopstick antennas

text: used in modern radios.

text: A Medium wave radio station is operated by All India Radio, with programs in Tamil, English and Hindi. Five FM radio stations operate from Coimbatore – Rainbow FM, Suryan FM, Radio Mirchi, Radio City and Hello FM. All these private radio stations air exclusively Tamil based programs, including film music. Television relay started in 1985 from Delhi Doordarshan and in 1986, after inception of the repeater tower at Kodaikanal, telecast from Madras commenced.  In 2005, Doordarshan opened its studio in Coimbatore. Television services are accessible through DTH or digital cable.

text: A

text: Medium wave radio

text: station is operated by

text: All India Radio

text: , with programs in Tamil, English and Hindi. Five

text: FM radio

text: stations operate from Coimbatore – Rainbow FM,

text: Suryan FM

text: Radio Mirchi

text: Radio City

text: and

text: Hello FM

text: Tamil

text: Doordarshan

text: and in 1986, after inception of the repeater tower at

text: Kodaikanal

text: , telecast from Madras commenced.  In 2005, Doordarshan opened its studio in Coimbatore. Television services are accessible through

text: DTH

text: or digital cable.

text: The waves are most often generated with a mechanical wavemaker, although there are also wind–wave flumes with (additional) wave generation by an air flow over the water – with the flume closed above by a roof above the free surface. The wavemaker frequently consists of a translating or rotating rigid wave board. Modern wavemakers are computer controlled, and can generate besides periodic waves also random waves, solitary waves, wave groups or even tsunami-like wave motion. The wavemaker is at one end of the wave flume, and at the other end is the construction being tested, or a wave absorber (a beach or special wave absorbing constructions).

text: The waves are most often generated with a mechanical wavemaker, although there are also wind–wave flumes with (additional) wave generation by an air flow over the water – with the flume closed above by a roof above the free surface. The wavemaker frequently consists of a translating or rotating rigid wave board. Modern wavemakers are computer controlled, and can generate besides

text: periodic

text: waves also

text: random wave

text: s,

text: solitary wave

text: s,

text: wave group

text: s or even

text: tsunami

text: -like wave motion. The wavemaker is at one end of the wave flume, and at the other end is the construction being tested, or a wave absorber (a beach or special wave absorbing constructions).

text: The Grouper line of products were networking devices that used spread-spectrum radio waves to communicate. Groupers could be attached to any PowerBook or used freestanding with any desktop Mac. Placing one Grouper on a wired network would have it serve as a hub for up to 15 other wireless Groupers. Keeping with Digital Ocean's theme, the collection of networked computers was called a school. Wireless devices could access the Grouper-enabled network from within a 250-foot distance indoors to an 800-foot distance outdoors, and the Grouper only used one-sixtieth the power of other comparable wireless devices.

text: On November 6, 2011, the Tri-city Herald reported that a Fargo, N.D., radio owner was paying more than $6 million to purchase 12 stations in the Tri-Cities and Yakima currently owned by New Northwest Broadcasters. Ingstad Radio Washington agreed to purchase — at a discount — more than $16 million in debt owed by Seattle-based New Northwest Broadcasters from a creditor, CIT Group. The Tri-Cities stations included in the sale are: KUJ-FM, a Top-40 hits station; KIOK-FM, a country station; KEGX-FM, a classic rock station; KTCR-AM, talk radio; KKSR-FM, a variety hits station; and KALE-AM, a FOX Sports affiliate. The Yakima stations are: KXDD-FM, a country station; KRSE-FM, a variety hits station; KJOX-AM, an ESPN affiliate; KARY-FM, an oldies station; KBBO-AM, a news radio station and KHHK-FM, a contemporary hit music station. The discounted price for Ingstad is about $6.7 million for all 12 stations.

text: . Thus, the input-plane plane wave spectrum is transformed into the output-plane plane wave spectrum through the multiplicative action of the system transfer function. It is at this stage of understanding that the previous background on the plane wave spectrum becomes invaluable to the conceptualization of Fourier optical systems.

text: When using medium to high frequency radio telecommunication, there are radio waves which travel both parallel to the ground, and towards the ionosphere, referred to as a ground wave and sky wave, respectively. A skip zone is an annular region between the farthest points at which the ground wave can be received and the nearest point at which the refracted sky waves can be received. Within this region, no signal can be received because, due to the conditions of the local ionosphere, the relevant sky waves are not reflected but penetrate the ionosphere.

text: When using medium to high frequency radio

text: telecommunication

text: , there are

text: radio waves

text: which travel both parallel to the ground, and towards the

text: ionosphere

text: , referred to as a

text: ground wave

text: and

text: sky wave

text: , respectively. A skip zone is an annular region between the farthest points at which the ground wave can be received and the nearest point at which the refracted sky waves can be received. Within this region, no signal can be received because, due to the conditions of the local ionosphere, the relevant sky waves are not reflected but penetrate the ionosphere.

text: "There are waves in the navy and waves in your hair,and people wave their hands when they're going anywhere,but the greatest waves there can be are the radio waves on WAVZ"

text: Prior to the 1920s, practical work on radio waves concentrated on the low frequency end of the radio spectrum, as these frequencies were better for long-range communication.  These were far below the frequencies that could propagate in even large waveguides, so there was little experimental work on waveguides during this period, although a few experiments were done.   In a June 1, 1894 lecture, "The work of Hertz", before the Royal Society, Oliver Lodge demonstrated the transmission of 3 inch radio waves from a spark gap through a short cylindrical copper duct. In his pioneering 1894-1900 research on microwaves, Jagadish Chandra Bose used short lengths of pipe to conduct the waves, so some sources credit him with inventing the waveguide.  However, after this, the concept of radio waves being carried by a tube or duct passed out of engineering knowledge.

text: Prior to the 1920s, practical work on radio waves concentrated on the low frequency end of the radio spectrum, as these frequencies were better for long-range communication.  These were far below the frequencies that could propagate in even large waveguides, so there was little experimental work on waveguides during this period, although a few experiments were done.   In a June 1, 1894 lecture, "The work of Hertz", before the

text: Royal Society

text: Oliver Lodge

text: demonstrated the transmission of 3 inch radio waves from a

text: spark gap

text: through a short cylindrical copper duct. In his pioneering 1894-1900 research on microwaves,

text: Jagadish Chandra Bose

text: used short lengths of pipe to conduct the waves, so some sources credit him with inventing the waveguide.  However, after this, the concept of radio waves being carried by a tube or duct passed out of engineering knowledge.

text: Visible-light astronomy encompasses a wide variety of observations via telescopes that are sensitive in the range of visible light (optical telescopes).  It includes imaging, where a picture of some sort is made of the object; photometry, where the amount of light coming from an object is measured, spectroscopy, where the distribution of that light with respect to its wavelength is measured, and polarimetry where the polarisation state of that light is measured.  An example of spectroscopy is the study of spectral lines to understand of what kind of matter light is going through. Visible astronomy also includes looking up at night (skygazing).  Visible-light astronomy is part of optical astronomy, and differs from astronomies based on invisible types of light in the electromagnetic radiation spectrum, such as radio waves, infrared waves, ultraviolet waves, X-ray waves and gamma-ray waves.

text: Visible-light astronomy encompasses a wide variety of

text: observation

text: s via

text: telescope

text: s that are sensitive in the range of

text: visible light

text: optical telescope

text: s).  It includes imaging, where a picture of some sort is made of the object;

text: photometry

text: , where the amount of light coming from an object is measured,

text: spectroscopy

text: , where the distribution of that light with respect to its

text: wavelength

text: is measured, and

text: polarimetry

text: where the

text: polarisation

text: state of that light is measured.  An example of

text: spectroscopy

text: is the study of

text: spectral line

text: s to understand of what kind of

text: matter

text: light is going through. Visible astronomy also includes looking up at night (

text: skygazing

text: ).  Visible-light astronomy is part of optical astronomy, and differs from astronomies based on invisible types of light in the

text: electromagnetic radiation spectrum

text: , such as

text: radio waves

text: infrared waves

text: ultraviolet waves

text: X-ray waves

text: and

text: gamma-ray waves

text: Many publications are available but French-speakers have primarily the daily L'Acadie Nouvelle, published in Caraquet, and the weekly L'Étoile, published in Dieppe. There is also  the weekly L'Aviron published in Campbellton. English-speakers in turn have the daily Telegraph-Journal, published in Saint John, and the weekly Campbellton Tribune. There is no television station in the region but Radio-Canada Acadie (CBAFT-DT), Ici RDI, Rogers TV, and CHAU-DT are the main French television networks. The main French radio stations are the Ici Radio-Canada Première and CIMS-FM from Balmoral. English-speakers have CBC Television, CBC News Network, Global Television Network, and CTV Television Network. English radio stations include CBC Radio and CKNB in Campbellton.

text: Many publications are available but French-speakers have primarily the daily

text: L'Acadie Nouvelle

text: , published in Caraquet, and the weekly L'Étoile, published in

text: Dieppe

text: . There is also  the weekly L'Aviron published in Campbellton. English-speakers in turn have the daily

text: Telegraph-Journal

text: , published in

text: Saint John

text: , and the weekly Campbellton Tribune. There is no television station in the region but

text: Radio-Canada Acadie

text: (CBAFT-DT),

text: Ici RDI

text: Rogers TV

text: , and

text: CHAU-DT

text: are the main French television networks. The main French radio stations are the

text: Ici Radio-Canada Première

text: and

text: CIMS-FM

text: from

text: Balmoral

text: . English-speakers have

text: CBC Television

text: CBC News Network

text: Global Television Network

text: , and

text: CTV Television Network

text: . English radio stations include

text: CBC Radio

text: and

text: CKNB

text: in Campbellton.

text: Optical rogue waves are rare pulses of light analogous to rogue or freak ocean waves. The term optical rogue waves was coined to describe rare pulses of broadband light arising during the process of supercontinuum generation—a noise-sensitive nonlinear process in which extremely broadband radiation is generated from a narrowband input waveform—in nonlinear optical fiber. In this context, optical rogue waves are characterized by an anomalous surplus in energy at particular wavelengths (e.g., those shifted to the red of the input waveform) and/or an unexpected peak power. These anomalous events have been shown to follow heavy-tailed statistics, also known as L-shaped statistics, fat-tailed statistics, or extreme-value statistics. These probability distributions are characterized by long tails: large outliers occur rarely, yet much more frequently than expected from Gaussian statistics and intuition. Such distributions also describe the probabilities of freak ocean waves and various phenomena in both the man-made and natural worlds. Despite their infrequency, rare events wield significant influence in many systems. Aside from the statistical similarities, light waves traveling in optical fibers are known to obey the similar mathematics as water waves traveling in the open ocean (the nonlinear Schrödinger equation), supporting the analogy between oceanic rogue waves and their optical counterparts. More generally, research has exposed a number of different analogies between extreme events in optics and hydrodynamic systems. A key practical difference is that most optical experiments can be done with a table-top apparatus, offer a high degree of experimental control, and allow data to be acquired extremely rapidly. Consequently, optical rogue waves are attractive for experimental and theoretical research and have become a highly studied phenomenon. The particulars of the analogy between extreme waves in optics and hydrodynamics may vary depending on the context, but the existence of rare events and extreme statistics in wave-related phenomena are common ground.

text: Optical rogue waves are rare pulses of light analogous to

text: rogue or freak ocean waves

text: . The term optical rogue waves was coined to describe rare

text: pulses

text: of broadband light arising during the process of

text: supercontinuum

text: generation—a noise-sensitive

text: nonlinear

text: process in which extremely broadband

text: radiation

text: is generated from a narrowband input waveform—in nonlinear optical fiber. In this context, optical rogue waves are characterized by an anomalous surplus in energy at particular

text: wavelength

text: s (e.g., those shifted to the red of the input waveform) and/or an unexpected peak power. These anomalous events have been shown to follow

text: heavy-tailed statistics

text: , also known as L-shaped statistics, fat-tailed statistics, or extreme-value statistics. These probability distributions are characterized by

text: long tail

text: s: large outliers occur rarely, yet much more frequently than expected from Gaussian statistics and intuition. Such distributions also describe the probabilities of freak ocean waves and various phenomena in both the man-made and natural worlds. Despite their infrequency, rare events wield significant influence in many systems. Aside from the statistical similarities, light waves traveling in optical fibers are known to obey the similar mathematics as

text: water waves

text: traveling in the open ocean (the

text: nonlinear Schrödinger equation

text: ), supporting the analogy between oceanic rogue waves and their optical counterparts. More generally, research has exposed a number of different analogies between extreme events in optics and hydrodynamic systems. A key practical difference is that most optical experiments can be done with a table-top apparatus, offer a high degree of experimental control, and allow data to be acquired extremely rapidly. Consequently, optical rogue waves are attractive for experimental and theoretical research and have become a highly studied phenomenon. The particulars of the analogy between extreme waves in

text: optics

text: and

text: hydrodynamics

text: may vary depending on the context, but the existence of

text: rare events

text: and extreme statistics in

text: wave

text: -related phenomena are common ground.

text: In elastodynamics, Love waves, named after Augustus Edward Hough Love, are horizontally polarized surface waves. The Love wave is a result of the interference of many shear waves (S–waves) guided by an elastic layer, which is welded to an elastic half space on one side while bordering a vacuum on the other side. In seismology, Love waves (also known as Q waves (Quer: German for lateral)) are surface seismic waves that cause horizontal shifting of the Earth during an earthquake. Augustus Edward Hough Love predicted the existence of Love waves mathematically in 1911.  They form a distinct class, different from other types of seismic waves, such as P-waves and S-waves (both body waves), or Rayleigh waves (another type of surface wave).  Love waves travel with a lower velocity than P- or S- waves, but faster than Rayleigh waves. These waves are observed only when there is a low velocity layer overlying a high velocity layer/ sub–layers.

text: In

text: elastodynamics

text: , Love waves, named after

text: Augustus Edward Hough Love

text: , are horizontally

text: polarized

text: surface wave

text: s. The Love wave is a result of the

text: interference

text: of many

text: shear wave

text: s (S–waves) guided by an elastic layer, which is welded to an elastic half space on one side while bordering a vacuum on the other side. In

text: seismology

text: , Love waves (also known as Q waves (Quer: German for lateral)) are

text: surface

text: seismic wave

text: s that cause horizontal shifting of the Earth during an

text: earthquake

text: . Augustus Edward Hough Love predicted the existence of Love waves mathematically in 1911.  They form a distinct class, different from other types of

text: seismic wave

text: s, such as

text: P-wave

text: s and

text: S-wave

text: s (both

text: body wave

text: s), or

text: Rayleigh waves

text: (another type of surface wave).  Love waves travel with a lower velocity than P- or S- waves, but faster than Rayleigh waves. These waves are observed only when there is a low velocity layer overlying a high velocity layer/ sub–layers.

text: Radio is the technology of using radio waves to carry information, such as sound, by systematically modulating properties of electromagnetic energy waves transmitted through space, such as their amplitude, frequency, phase, or pulse width. When radio waves strike an electrical conductor, the oscillating fields induce an alternating current in the conductor. The information in the waves can be extracted and transformed back into its original form.

text: Radio is the

text: technology

text: of using

text: radio wave

text: s to carry information, such as sound, by systematically

text: modulating

text: properties of electromagnetic energy waves transmitted through space, such as their

text: amplitude

text: frequency

text: phase

text: , or

text: pulse width

text: . When radio waves strike an

text: electrical conductor

text: , the oscillating fields induce an

text: alternating current

text: in the conductor. The information in the waves can be

text: extracted

text: and transformed back into its original form.

text: Thomasville has one licensed AM radio station, WJDB, and two licensed FM radio stations, WDLG and WJDB-FM.

text: Thomasville has one licensed

text: AM

text: radio station,

text: WJDB

text: , and two licensed

text: FM

text: radio stations,

text: WDLG

text: and

text: WJDB-FM

text: It inhabits low wave energy habitats, such as mangrove swamps, borrow pits, and mooring canals.

text: is sufficiently deep to have a bound state. The condition for there to be just one bound state allows one to solve for the imaginary part of the wave frequency,

text: In response, Octavian increased the personal attacks against Antony, but the Senate and people of Rome were not convinced. Octavian’s chance came when Antony married Cleopatra in 32 BC before he divorced Octavia. That action combined with information that Antony was planning to establish a second Senate in Alexandria created the perfect environment for Octavian to strip Antony of his power.

text: In response, Octavian increased the personal attacks against Antony, but the

text: Senate and people of Rome

text: were not convinced. Octavian’s chance came when Antony married Cleopatra in 32 BC before he divorced Octavia. That action combined with information that Antony was planning to establish a second Senate in Alexandria created the perfect environment for Octavian to strip Antony of his power.

text: Henrietta is an 18th-century novel by Scottish author Charlotte Lennox. The first edition was published in 1758, and the second edition, revised by Lennox was published in 1761.

text: Henrietta is an

text: 18th-century novel

text: by Scottish author

text: Charlotte Lennox

text: . The first edition was published in 1758, and the second edition, revised by Lennox was published in 1761.

text: Euchelus eucastus is a species of sea snail, a marine gastropod mollusk in the family Chilodontidae.

text: Euchelus eucastus is a

text: species

text: of

text: sea snail

text: , a

text: marine

text: gastropod

text: mollusk

text: in the

text: family

text: Chilodontidae

text: Eid al-Fitr and Eid al-Adha are the festivals celebrated by the Muslim community of Biratnagar. Christmas is celebrated by a very small population of Christian minority.

text: Eid al-Fitr

text: and

text: Eid al-Adha

text: are the festivals celebrated by the Muslim community of Biratnagar. Christmas is celebrated by a very small population of Christian minority.

text: The domestic channels are broadcast on FM and AM frequencies. Radio Bulgaria broadcasts principally on shortwave plus one medium-wave frequency. All stations are also available online.

text: The domestic channels are broadcast on

text: FM

text: and

text: AM

text: frequencies. Radio Bulgaria broadcasts principally on

text: shortwave

text: plus one

text: medium-wave

text: frequency. All stations are also available

text: online

text: Radio waves were first predicted by mathematical work done in 1867 by Scottish mathematical physicist James Clerk Maxwell. Maxwell noticed wavelike properties of light and similarities in electrical and magnetic observations. His mathematical theory, now called Maxwell's equations, described light waves and radio waves as waves of electromagnetism that travel in space, radiated by a charged particle as it undergoes acceleration. In 1887, Heinrich Hertz demonstrated the reality of Maxwell's electromagnetic waves by experimentally generating radio waves in his laboratory, showing that they exhibited the same wave properties as light:  standing waves, refraction, diffraction, and polarization.  Radio waves were first used for communication in the mid 1890s by Guglielmo Marconi, who developed the first practical radio transmitters and receivers.

text: Radio waves were first predicted by mathematical work done in 1867 by Scottish mathematical physicist

text: James Clerk Maxwell

text: . Maxwell noticed wavelike properties of light and similarities in electrical and magnetic observations. His mathematical theory, now called

text: Maxwell's equations

text: , described light waves and radio waves as waves of electromagnetism that travel in space, radiated by a charged particle as it undergoes acceleration. In 1887,

text: Heinrich Hertz

text: demonstrated the reality of Maxwell's electromagnetic waves by experimentally generating radio waves in his laboratory, showing that they exhibited the same wave properties as light:

text: standing wave

text: s,

text: refraction

text: diffraction

text: , and

text: polarization

text: .  Radio waves were first used for communication in the mid 1890s by

text: Guglielmo Marconi

text: , who developed the first practical radio

text: transmitter

text: s and

text: receivers

text: Faber and Faber Limited, often abbreviated to Faber, is an independent publishing house in the United Kingdom. Faber has published some of the most well-known literature in the English language, including William Golding's Lord of the Flies. Poet T. S. Eliot was once a Faber editor.

text: Faber and Faber Limited, often abbreviated to Faber, is an independent publishing house in the

text: United Kingdom

text: . Faber has published some of the most well-known literature in the English language, including

text: William Golding

text: 's

text: Lord of the Flies

text: . Poet

text: T. S. Eliot

text: was once a Faber editor.

text: There are several subspecies as follows:

text: There are several

text: subspecies

text: as follows:

text: In 1970, Marcos was sent to England where he lived and studied at Worth School an all-boys Benedictine institution. Thereafter, he pursued his undergraduate degree. He graduated with a Special Diploma in Social Studies from Oxford University in England.

text: In 1970, Marcos was sent to England where he lived and studied at

text: Worth School

text: an all-boys

text: Benedictine

text: institution. Thereafter, he pursued his undergraduate degree. He graduated with a Special Diploma in Social Studies from

text: Oxford University

text: in England.

text: EP argues that to properly understand the functions of the brain, one must understand the properties of the environment in which the brain evolved. That environment is often referred to as the "environment of evolutionary adaptedness" (EEA).

text: Dichocrocis credulalis is a moth in the Crambidae family. It was described by Snellen in 1890. It is found in India (Sikkim).

text: Dichocrocis credulalis is a

text: moth

text: in the

text: Crambidae

text: family. It was described by Snellen in 1890. It is found in

text: India

text: (Sikkim).

text: Top 40 Waves received the award in the category National Radio in 1985. In 1998 both received Ondas Awards for Best Presenter Joaquin Luqui Musical Program and the 40 to 1 for Best TV Specialist Program. The program Your place or mine got in 2000 Ondas Award Most Innovative Radio Program, original and for their service to society. In 2004, the alarm Anda Ya! received the Innovation Award to radio waves. In 2010, Frank White is awarded the Gold Antenna Federation of Radio and Television Spain1

text: Electronic harassment is the unproven belief of the use of electromagnetic waves to harass a victim. Psychologists have identified evidence of auditory hallucinations, delusional disorders, or other mental illnesses in online communities supporting those who claim to be targeted.

text: Electronic harassment is the unproven belief of the use of

text: electromagnetic wave

text: s to harass a victim. Psychologists have identified evidence of

text: auditory hallucination

text: s,

text: delusional disorder

text: s, or other mental illnesses in online communities supporting those who claim to be targeted.

text: This motivated efforts to produce radio frequency oscillations that decayed more slowly; had less damping.  There is an inverse relation between the rate of decay (the time constant) of a damped wave and its bandwidth; the longer the damped waves take to decay toward zero, the narrower the frequency band the radio signal occupies, so the less it interferes with other transmissions. As more transmitters began crowding the radio spectrum, reducing the frequency spacing between transmissions, government regulations began to limit the maximum damping or "decrement" a radio transmitter could have.  Manufacturers produced spark transmitters which generated long "ringing" waves with minimal damping.

text: This motivated efforts to produce radio frequency oscillations that decayed more slowly; had less damping.  There is an inverse relation between the rate of decay (the

text: time constant

text: ) of a damped wave and its bandwidth; the longer the damped waves take to decay toward zero, the narrower the frequency band the radio signal occupies, so the less it interferes with other transmissions. As more transmitters began crowding the radio spectrum, reducing the frequency spacing between transmissions, government regulations began to limit the maximum damping or "decrement" a radio transmitter could have.  Manufacturers produced spark transmitters which generated long "ringing" waves with minimal damping.

text: The Irish Cultural Society of San Antonio, Ancient Order of Hibernians Columkille Division 1, and The Harp & Shamrock Society of Texas, all San Antonio Irish organizations have all been long time supporters and partners of the SAGAC.  This year (2014), that will be commemorated as their crests will be added the 2014 SAGAC San Patricio Jerseys.

text: Gardner's explanation aside, individual interpretations of the exact natures of the gods differ significantly, since priests and priestesses develop their own relationships with the gods through intense personal work and revelation. Many have a duotheistic conception of deity as a Goddess (of Moon, Earth and sea) and a God (of forest, hunting and the animal realm). This concept is often extended into a kind of polytheism by the belief that the gods and goddesses of all cultures are aspects of this pair (or of the Goddess alone). Others hold the various gods and goddesses to be separate and distinct. Janet Farrar and Gavin Bone have observed that Wicca is becoming more polytheistic as it matures, and embracing a more traditional pagan worldview.Many groups and individuals are drawn to particular deities from a variety of pantheons (often Celtic, Greek, or from elsewhere in Europe), whom they honour specifically. Some examples are Cernunnos and Brigit from Celtic mythology,  Hecate, Lugh, and Diana.

text: Gardner's explanation aside, individual interpretations of the exact natures of the gods differ significantly, since priests and priestesses develop their own relationships with the gods through intense personal work and

text: revelation

text: . Many have a

text: duotheistic

text: conception of deity as a Goddess (of Moon, Earth and sea) and a God (of forest, hunting and the animal realm). This concept is often extended into a kind of

text: polytheism

text: by the belief that the gods and goddesses of all cultures are aspects of this pair (or of the Goddess alone). Others hold the various gods and goddesses to be separate and distinct.

text: Janet Farrar

text: and

text: Gavin Bone

text: have observed that Wicca is becoming more polytheistic as it matures, and embracing a more traditional pagan worldview.Many groups and individuals are drawn to particular deities from a variety of

text: pantheons

text: (often

text: Celtic

text: Greek

text: , or from elsewhere in Europe), whom they honour specifically. Some examples are

text: Cernunnos

text: and

text: Brigit

text: from

text: Celtic mythology

text: Hecate

text: Lugh

text: , and

text: Diana

text: Although most measuring devices estimate the significant wave height from a wave spectrum, satellite radar altimeters are unique in measuring directly the significant wave height thanks to the different time of return from wave crests and troughs within the area illuminated by the radar. The maximum ever measured wave height from a satellite is 20.1m during a North Atlantic storm in 2011.

text: Although most measuring devices estimate the significant wave height from a

text: wave spectrum

text: , satellite radar altimeters are unique in measuring directly the significant wave height thanks to the different time of return from wave crests and troughs within the area illuminated by the radar. The maximum ever measured wave height from a satellite is 20.1m during a North Atlantic storm in 2011.

text: Semutophila is a genus of moths belonging to the subfamily Olethreutinae of the family Tortricidae.

text: Semutophila is a genus of

text: moth

text: s belonging to the subfamily

text: Olethreutinae

text: of the family

text: Tortricidae

text: In Greece, Plutarch wrote that Xenocrates discovered the number of different syllables possible in the Greek language. This, however, is unlikely because this is one of the few mentions of Combinatorics in Greece. The number they found, 1.002 × 10 also seems too round to be more than a guess.

text: In Greece,

text: Plutarch

text: wrote that

text: Xenocrates

text: discovered the number of different syllables possible in the Greek language. This, however, is unlikely because this is one of the few mentions of Combinatorics in Greece. The number they found, 1.002 × 10 also seems too round to be more than a guess.

text: Ed Young may refer to:

text: Ed Young may refer to:

text: Libya issued maps from around 1969 showing the Toummo Triangle area (approximately 19,400 square km) as Libyan territory.

text: In 1645, it passed to Swedish control by the Treaty of Brömsebro after the Danish defeat in the Torstenson War. Queen Christina of Sweden granted to her favourite Magnus Gabriel de la Gardie the title of a Count of Arensburg, the German and Swedish name by which Kuressaare was known at that time. The city was burnt to the ground by Russian troops in 1710 during the Great Northern War and suffered heavily from the plague. Abandoned by the Swedish it was incorporated into the Governorate of Livonia of the Russian Empire with the 1721 Treaty of Nystad.

text: In 1645, it passed to

text: Swedish

text: control by the

text: Treaty of Brömsebro

text: after the Danish defeat in the

text: Torstenson War

text: . Queen

text: Christina of Sweden

text: granted to her favourite

text: Magnus Gabriel de la Gardie

text: the title of a Count of Arensburg, the German and

text: Swedish

text: name by which Kuressaare was known at that time. The city was burnt to the ground by Russian troops in 1710 during the

text: Great Northern War

text: and suffered heavily from the

text: plague

text: . Abandoned by the Swedish it was incorporated into the

text: Governorate of Livonia

text: of the

text: Russian Empire

text: with the 1721

text: Treaty of Nystad

text: 1979 saw the launch of a new variety of AM radio station. XEZV-AM came to air in Tlapa de Comonfort, Guerrero, operated by the National Indigenist Institute. "The Voice of the Mountains" was part of an initiative to promote educational and social development in indigenous regions of Mexico. In 1982, four more stations were launched; today, the INI's successor, the CDI, operates the Sistema de Radiodifusoras Culturales Indigenistas composed of 15 medium-wave radio services and several experimental FM radio stations broadcasting in 31 languages.

text: 1979 saw the launch of a new variety of AM radio station.

text: XEZV-AM

text: came to air in

text: Tlapa de Comonfort, Guerrero

text: , operated by the

entity_name: National Commission for the Development of Indigenous Peoples

text: National Indigenist Institute

text: . "The Voice of the Mountains" was part of an initiative to promote educational and social development in indigenous regions of Mexico. In 1982, four more stations were launched; today, the INI's successor, the

text: CDI

text: , operates the

entity_name: Sistema de Radiodifusoras Culturales Indigenistas

text: Sistema de Radiodifusoras Culturales Indigenistas

text: composed of 15 medium-wave radio services and several experimental FM radio stations broadcasting in 31 languages.

text: The Gurindji strike (or Wave Hill Walk-Off) was a walk-off and strike by 200 Gurindji stockmen, house servants and their families in August 1966 at Wave Hill cattle station in Kalkarindji (formerly known as Wave Hill), Northern Territory.

text: The Gurindji strike (or Wave Hill Walk-Off) was a walk-off and strike by 200

text: Gurindji

text: stockmen

text: , house

text: servants

text: and their families in August 1966 at

text: Wave Hill

text: cattle station

text: in

text: Kalkarindji

text: (formerly known as Wave Hill),

text: Northern Territory

text: The story of Radio Joya, as XHFM was known, was cut short on July 28, 1957, when an earthquake led to the total destruction of its studio facilities. However, the concession lived on. In 1958, as Obregón Cruces began to focus on building a new AM radio station, XHFM's concession passed to Francisco Aguirre Jiménez, the founder of Radio Centro. Owing to the low penetration of FM receivers and the preference of advertisers for AM, the station remained off the air until 1974, but during this period, significant changes were occurring. A realignment of Mexico City FM frequencies shifted the first few stations 400 kHz and led to a move to 93.7. Additionally, as was already the case with Radio Centro's other FM stations, the callsign was changed to match one of the company's existing AM outlets and XHFM became XEJP-FM. The XHFM callsign would not return to Mexican radio until 2010, when an unrelated XHFM signed on in Veracruz.

text: The story of Radio Joya, as XHFM was known, was cut short on July 28, 1957, when an earthquake led to the total destruction of its studio facilities. However, the concession lived on. In 1958, as Obregón Cruces began to focus on building

text: a new AM radio station

text: , XHFM's concession passed to Francisco Aguirre Jiménez, the founder of Radio Centro. Owing to the low penetration of FM receivers and the preference of advertisers for AM, the station remained off the air until 1974, but during this period, significant changes were occurring. A realignment of Mexico City FM frequencies shifted the first few stations 400 kHz and led to a move to 93.7. Additionally, as was already the case with Radio Centro's other FM stations, the callsign was changed to match one of the company's existing AM outlets and XHFM became XEJP-FM. The XHFM callsign would not return to Mexican radio until 2010, when

text: an unrelated XHFM

text: signed on in Veracruz.

text: Rock Island Arsenal started work on a new medium tank, based on the design of the M2 Light Tank. Initially designated the T5, the redesigned model (with a 350 hp R-975 radial engine) was re-designated as the M2 Medium Tank in June, 1939. After the first 18 units had been produced at Rock Island Arsenal and evaluated by the Army, the upgraded M2A1 specification was approved with a redesigned turret and a more powerful engine.

text: Rock Island Arsenal

text: started work on a new medium tank, based on the design of the

text: M2 Light Tank

text: . Initially designated the T5, the redesigned model (with a 350 hp R-975 radial engine) was re-designated as the M2 Medium Tank in June, 1939. After the first 18 units had been produced at Rock Island Arsenal and evaluated by the Army, the upgraded M2A1 specification was approved with a redesigned turret and a more powerful engine.

text: Since the interlaced signal contains the two fields of a video frame shot at two different times, it enhances motion perception to the viewer and reduces flicker by taking advantage of the persistence of vision effect. This results in an effective doubling of time resolution as compared with non-interlaced footage (for frame rates equal to field rates). However, interlaced signal requires a display that is natively capable to show the individual fields in a sequential order, and only traditional CRT-based TV sets are capable of displaying interlaced signal, due to the electronic scanning and lack of apparent fixed resolution.

text: Since the interlaced signal contains the two fields of a video frame shot at two different times, it enhances motion perception to the viewer and reduces

text: flicker

text: by taking advantage of the

text: persistence of vision

text: effect. This results in an effective doubling of time resolution as compared with non-interlaced footage (for frame rates equal to field rates). However, interlaced signal requires a display that is natively capable to show the individual fields in a sequential order, and only traditional

text: CRT

text: -based TV sets are capable of displaying interlaced signal, due to the electronic scanning and lack of apparent fixed resolution.

text: Since then she has written ten novels, three screenplays and edited two books of essays. She has worked in television and radio as a producer and presenter: most notably for BBC Television where for seven years (1989–1996) she presented the live nightly culture programme The Late Show.  After that she presented the BBC Radio 3 radio programme Night Waves.

text: Since then she has written ten novels, three screenplays and edited two books of essays. She has worked in television and radio as a producer and presenter: most notably for

text: BBC Television

text: where for seven years (1989–1996) she presented the live nightly culture programme

text: The Late Show

text: .  After that she presented the

text: BBC Radio 3

text: radio programme

text: Night Waves

text: This story began as early as the Tang Dynasty and became popular during the Song Dynasty. It's proved to be impracticable as Lu Xiujing had a visible age difference from the other two.

text: This story began as early as the

text: Tang Dynasty

text: and became popular during the

text: Song Dynasty

text: . It's proved to be impracticable as Lu Xiujing had a visible age difference from the other two.

text: (on a loan from AEK Athens)

text: (on a loan from

text: AEK Athens

text: Horstmann died at age 89 on January 11, 2001, in New Haven, Connecticut due to complications of Alzheimer's disease.

text: Horstmann died at age 89 on January 11, 2001, in

text: New Haven, Connecticut

text: due to complications of

text: Alzheimer's disease

text: The member states of the union are members; however the Council Regulation establishing it provided that other states may become members of it by means of agreements concluded between them and the EU.

text: The

text: member states

text: of the union are members; however the Council Regulation establishing it provided that other states may become members of it by means of agreements concluded between them and the EU.

text: Two generic types of wave turbulence should be distinguished: statistical wave turbulence (SWT) and discrete wave turbulence (DWT).

text: 1926 -Introduction of Radio Technology programme

text: Wave Monkey

text: Wave Monkey

text: Veals was born in Baton Rouge, Louisiana. He went to Istrouma High School. Veals enrolled in Tulane University and played football for the Tulane Green Wave.

text: Veals was born in

text: Baton Rouge, Louisiana

text: . He went to

text: Istrouma High School

text: . Veals enrolled in

text: Tulane University

text: and played football for the

text: Tulane Green Wave

text: Originally known as WTRF, the station signed on the air for the first time in 1947 on both the AM and FM bands. Fittingly, the call sign stood for "Two Radio Frequencies." If briefly became WTRX then, in 1959, WOMP.

text: 33.6 - 3ABN Radio Latino(audio only)

text: 33.6 - 3ABN Radio Latino(audio only)