Welcome to Wikipedia's portal for Radio.
Radio is the wireless transmission of signals, by modulation of electromagnetic waves with frequencies below those of visible light.
Electromagnetic radiation travels via oscillating electromagnetic fields that pass through the air and the vacuum of space. It does not require a medium of transport. Information is carried by systematically changing (modulating) some property of the radiated waves, such as their amplitude or their frequency. When radio waves pass an electrical conductor, the oscillating fields induce an alternating current in the conductor.
The word 'radio' is used to describe this phenomenon, and television, radio, and cell phone transmissions are all classified as radio frequency emissions.
Modulation is the process where speech, music and the like are impressed onto the carrier wave of a transmission. Detection or demodulation is the reverse process which takes place in a receiver. The speech, music etc. is recovered and may then be amplified and applied to an ear piece or a loud speaker. The most common forms of modulation are Amplitude Modulation (AM) and Frequency Modulation (FM) both of which use different modulation and detection circuits. Cell phones, digital radio and digital television use more complex modulation and demodulation systems.
The simplest AM receiver is the Crystal Set or Crystal Radio. Demodulation is achieved by a semiconductor diode. One of the earliest forms of detection consisted of a thin copper wire in contact with a small chunk of Galena Rock. Adequate signals could be heard in headphones for up to 50 km with simple arrangements.
The electromagnetic spectrum
is the range of all possible electromagnetic radiation
. Also, the "electromagnetic spectrum" (usually just spectrum
) of an object is the range of electromagnetic radiation that it emits
, or transmits.
The electromagnetic spectrum, extends from the frequencies used in electric power grids (at the long-wavelength end) to gamma radiation (at the short-wavelength end), covering wavelengths from thousands of kilometres down to fractions of the size of an atom. It is commonly said that EM waves beyond these limits are uncommon, although this is not actually true. The 22-year sunspot cycle, for instance, produces radiation with a period of 22 years, or a frequency of 1.4*10−9 Hz. At the other extreme, photons of arbitrarily high frequency may be produced by colliding electrons with positrons at appropriate energy. 1024 Hz photons can be produced today with man-made accelerators. In our universe the short wavelength limit is likely to be the Planck length, and the long wavelength limit is the size of the universe itself (see physical cosmology), though in principle the spectrum is infinite.
This photo shows an early 1930s wooden radio receiver in the classic "cathedral" shape, which was designed and built by Philco. Philco, at the time of this radio's construction, was the leading manufacturer of radios. Photo Credit: User:Gmaxwell
BBC Radio 2 is one of the BBC's national radio stations and is the most popular station in the UK. It broadcasts throughout the UK on FM radio between 88 and 91 MHz from its studios in Western House, adjacent to Broadcasting House in central London. Programmes are also relayed on DAB, Sky Digital, Cable TV, Freeview and the Internet.
The station started at 7:00am on September 30, 1967, and succeeded the Light Programme, with some of the Light's music shows transferring to the newly-launched Radio 1. The first show however had actually started at 5.30am (on the Light programme) but continued on with Breakfast Special from Paul Hollingdale as Radio 1 split off.
||Nobody seems to know yet how television is going to affect the radio, movies, love, housekeeping or the church, but it has definitely revived vaudeville.
John Peel, OBE (30 August 1939 – 25 October 2004), was a British disc jockey, radio presenter, and journalist.
He was one of the original DJs of Radio 1 in 1967 and the only one remaining on Radio 1 at the time of his death. Known for the extraordinary range of his taste in music and the occasional mistakes (such as playing records at the wrong speed) that marked his shows, John Peel was one of the most popular and respected DJs and broadcasters in the world. He was one of the first to play reggae and punk on British radio. His profound influence on alternative rock, pop, and dance music is widely acknowledged. The BBC also released albums of his BBC shows, bands like Joy Division, The Fall, Clash. Live and upfront in the BBC studio.
- 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, Alice Faye, Stan Freberg, Phil Harris, Bob Hope, 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, 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