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.
Radio systems need a transmitter to modulate (change) some property of the energy produced to impress a signal on it, for example using amplitude modulation or angle modulation (which can be frequency modulation or phase modulation). Radio systems also need an antenna to convert electric currents into radio waves, and radio waves into an electric current. An antenna can be used for both transmitting and receiving. The electrical resonance of tuned circuits in radios allow individual frequencies to be selected. The electromagnetic wave is intercepted by a tuned receiving antenna. A radio receiver receives its input from an antenna and converts it into a form that is usable for the consumer, such as sound, pictures, digital data, measurement values, navigational positions, etc. 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.
An audio signal (top) may be carried by an AM or FM radio wave.
Degen DE1103, an advanced world mini-receiver with single sideband modulation and dual conversion
Bakelite radio at the Bakelite Museum, Orchard Mill, Williton, Somerset, UK.
Radio communication. Information such as sound is converted by a transducer such as a microphone to an electrical signal, which modulates a radio wave sent from a transmitter. A receiver intercepts the radio wave and extracts the information-bearing electronic signal, which is converted back using another transducer such as a speaker.
2008 Pure One Classic digital radio
A Fisher 500 AM/FM hi-fi receiver from 1959.
||When buying a used car, punch the buttons on the radio. If all the stations are rock and roll, there's a good chance the transmission is shot.
Sir Michael Terence Wogan, KBE DL (born August 3 1938) more commonly known as Terry Wogan, is a veteran Irish radio and television broadcaster, who has worked for the British Broadcasting Corporation in the United Kingdom for most of his career. He has been a leading media personality in Ireland and the UK since the late 1960s, and is often referred to as a "national treasure" of both the United Kingdom and his native Ireland.
Terry Wogan, the son of a grocery store manager in Limerick, was educated at the Jesuit school of Crescent College from the age of eight. He experienced a strong religious upbringing, later commenting that "There were hundreds of churches, all these missions breathing fire and brimstone, telling you how easy it was to sin, how you'd be in hell. We were brainwashed into believing." Despite this, he has often expressed his fondness for the city of his birth, commenting on one occasion that "Limerick never left me, whatever it is, my identity is Limerick."
- Radio December 12, 2006 "...to create, expand, and maintain wikipedia articles related to radio, including radio propagation and reception, radio programming, radio personalities, and the business of radio." (Example: Mutual Broadcasting System)
- Amateur Radio August 24, 2006 "...to improve Wikipedia's articles related to Amateur radio, maintain the amateur radio category and its sub-categories for clean organization, and to produce and maintain templates for Amateur radio-related topic identification." (Example: Amateur radio)
- Radio Stations February 15, 2005 "...to coordinate the activities of creating and maintaining articles about radio stations." (Example: Pulse FM Kingborough & Huon)
- Podcasting January 21, 2007 "...to make Wikipedia's knowledge of notable Podcast and podcast-related information as complete as possible." (Example: Podcast)
||Music radio, Old-time radio, Radio comedy, Radio documentary, Radio drama, Top 40
||BBC Radio, Blue Network, Columbia Broadcasting System, Mutual Broadcasting System, National Broadcasting Company, Sirius Satellite Radio, XM Satellite Radio
||Fred Allen, Gracie Allen, Don Ameche, Jack Benny, Edgar Bergen, Jagadish Chandra Bose, George Burns, Ronald Colman, Jim Connors, Frank Conrad, Norman Corwin, Frankie Crocker, Alice Faye, Stan Freberg, Vaughn Harper, Phil Harris, Bob Hope, Hal Jackson, Spike Jones, Hans von Kaltenborn, Kay Kyser, Frances Langford, Guglielmo Marconi, Elizabeth McLeod, J. Carrol Naish, Ozzie Nelson, Arch Oboler, Dorothy Parker, Virginia Payne, Harold Peary, David Sarnoff, Red Skelton, Kate Smith, Howard Stern, Nikola Tesla, Jonathan Toubin, Lurene Tuttle, Rudy Vallée, Fred Waring, Orson Welles
||Abbott and Costello, Amos 'n' Andy, Arch Oboler's Plays, Burns and Allen, Cavalcade of America, CBS Radio Mystery Theater, Dragnet, Duffy's Tavern, Fibber McGee and Molly, The Goldbergs, The Howard Stern Show, Inner Sanctum Mysteries, The Jack Benny Program, Life with Luigi, Lights Out, Lux Radio Theater, Opie and Anthony, The Archers, The Hitchhiker's Guide to the Galaxy, The Phil Harris-Alice Faye Show, Quiz Kids, The Screen Guild Theater, The Shadow, Suspense, Theater Guild on the Air, Twenty Questions, The Whistler, Yours Truly, Johnny Dollar
||Amateur radio, AM broadcasting, FM broadcasting, International broadcasting, Internet Radio, Digital Radio Mondiale, HD Radio, Digital Audio Broadcasting and GNU Radio, Software-defined radio, Transistor radio, Vacuum tube