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.
Amateur radio or ham radio is a hobby that is practised by over 16,000 licensed users in India. Licences are granted by the Wireless and Planning and Coordination Wing (WPC), a branch of the Ministry of Communications and Information Technology. In addition, the WPC allocates frequency spectrum in India. The Indian Wireless Telegraphs (Amateur Service) Rules, 1978 lists five licence categories:
To obtain a licence in the first four categories, candidates must pass the Amateur Station Operator's Certificate examination conducted by the WPC. This exam is held monthly in Delhi, Mumbai, Kolkata and Chennai, every two months in Ahmedabad, Nagpur and Hyderabad, and every four months in some smaller cities. The examination consists of two 50-mark written sections: Radio theory and practice, Regulations; and a practical test consisting of a demonstration of Morse code proficiency in sending and receiving. After passing the examination, the candidate must clear a police interview. After clearance, the WPC grants the licence along with the user-chosen call sign. This procedure can take up to one year. This licence is valid for up to five years.
Each licence category has certain privileges allotted to it, including the allotment of frequencies, output power, and the emission modes. This article list the various frequencies allotted to various classes, and the corresponding emission modes and input DC power.
||The whole country was tied together by radio. We all experienced the same heroes and comedians and singers. They were giants.
Fred Allen (born John Florence Sullivan on May 31, 1894 in Cambridge, Massachusetts, died March 17, 1956 in New York City) was an American comedian whose absurdist, pointed radio show (1934–1949) made him one of the most popular and forward-looking humorists in the so-called classic era of American radio.
His best-remembered gag may be his long-running mock feud with friend and fellow comedian Jack Benny. Allen has been considered one of the more accomplished, daring and relevant humorists of his time. A master ad libber, he constantly battled censorship and developed routines the style and substance of which influenced future comic talents. Perhaps more than any of his generation, Fred Allen wielded influence that outlived both his contemporaries and the medium that made him famous.
- 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