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.
The Hitchhiker's Guide to the Galaxy is a science fiction comedy radio series written by Douglas Adams (with some material in the first series provided by John Lloyd). It was originally broadcast in the United Kingdom by the BBC, and was soon afterwards broadcast on global short wave radio on the BBC World Service, in 1978. Broadcasting by National Public Radio (one of their first to occur in stereo) in the United States followed in March, 1981, with a repeat broadcast in September. The following year, 1982, the BBC series was carried by CBC Radio (Canadian Broadcasting Corporation).
A pilot programme was commissioned in March 1977, and was recorded by the end of the following June. A second series was commissioned in 1979, and this was transmitted in 1980. Episodes of the first series were specially re-recorded for release on LP records and cassettes. After the 1980 transmissions of the second radio series, the first series was adapted for television; it included some material originally written by Adams for stage adaptations and the aforementioned LP adaptation. This in turn was followed by five novels, a computer game, and adaptations into three series of comic books.
Adams considered writing a third radio series, to be based on his novel Life, the Universe and Everything, in 1993 but the project did not begin for another ten years, after Adams's death. Dirk Maggs, with whom Adams had discussed the new series in 1993, 1997 and 2000, eventually directed and co-produced radio series adaptations of that novel, as well as So Long, and Thanks for All the Fish and Mostly Harmless. These became the third, fourth and fifth radio series. The third series was recorded in 2003 and transmitted in September and October 2004, and the fourth and fifth series were recorded in late 2004 and early 2005 and transmitted in May and June 2005. Recordings of all five series have been released on audio cassette and compact disc, and the third series was released on DVD in 2006, after being "delayed" more than once.
Bakelite radio at the Bakelite Museum, Orchard Mill, Williton, Somerset, UK.
A Fisher 500 AM/FM hi-fi receiver from 1959.
2008 Pure One Classic digital radio
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.
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
||My father hated radio and could not wait for television to be invented so he could hate that too.
Howard Stern (born Howard Allen Stern on January 12, 1954) is an American radio and TV personality, media mogul, humorist, actor, and author. He is best known for his national radio show, which for many years was syndicated on FM radio stations (and a few AM stations) throughout the United States until his last terrestrial radio broadcast on December 16, 2005. He began broadcasting on the subscription-based Sirius satellite radio service on January 9, 2006.
The self-proclaimed "King of All Media" (a humorous reference to Michael Jackson's appellation "The King of Pop") has been dubbed a shock jock for his highly controversial use of scatological, sexual and racial humor. Stern has said that the show was never about shocking people, but primarily intended to offer his honest opinions on a gamut of issues (ranging from world affairs to problems among his own staff). Though controversial, he is one of the highest-paid radio personalities in the United States and the most fined personality in radio broadcast history.
- 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