The Radio Portal
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.
BBC Local Radio is the BBC's regional radio service for England and the Channel Islands, consisting of 40 stations. Initially, stations had to be co-funded by the BBC and local authorities, which only some Labour-controlled areas proved willing to do. Radio Leicester was the first to launch on 8 November 1967, followed by Sheffield, Merseyside and Nottingham. By the early 1970s, the local authority funding requirement was dropped, and stations spread across the country; many city-based stations later expand their remit to cover an entire county. Today, stations are asked to target their coverage to Dave and Sue, two fictional fifty-five-year-olds.
||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.
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