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Long wave radio broadcasting station, Motala, Sweden
Broadcasting tower in Trondheim, Norway
"On air" redirects here. For other uses, see On air (disambiguation). Radio broadcasting is a one-way wireless transmission over radio waves intended to reach a wide audience. Stations can be linked in radio networks to broadcast a common radio format, either in broadcast syndication or simulcast or both. Audio broadcasting also can be done via cable radio, local wire television networks,satellite radio, and internet radio via streaming media on the Internet. The signal types can be either analog audio or digital audio. Amateur radio (also, ham radio) is a form of radio broadcasting that is the private use of designated radio bands, for purposes of private recreation, non-commercialexchange of messages, experimentation, self-training, and emergency communication. Contents [hide] * 1 History * 2 Types * 2.1 Shortwave * 2.2 AM * 2.3 FM * 2.4 Pirate radio * 2.5 Terrestrial digital radio * 2.6 Satellite * 3 Program formats * 4 See also * 5 References * 6 Further reading * 7 External links| -------------------------------------------------
Main article: History of radio
The earliest radio stations were simply radiotelegraphy systems and did not carry audio. The first claimed audio transmission that could be termed a broadcastoccurred on Christmas Eve in 1906, and was made by Reginald Fessenden. Whether this broadcast actually took place is disputed. While many early experimenters attempted to create systems similar to radiotelephone devices where only two parties were meant to communicate, there were others who intended to transmit to larger audiences. Charles Herrold started broadcasting in California in 1909 and was carrying audio by the next year. (Herrold's station eventually becameKCBS). For the next decade, radio tinkerers had to build their own radio receivers. In The Hague, the Netherlands, PCGG started broadcasting on November 6, 1919. In 1916, Frank Conrad, an employee for the Westinghouse Electric Corporation, began broadcasting from his Wilkinsburg, Pennsylvania garage with the call letters 8XK. Later, the station was moved to the top of the Westinghouse factory building in East Pittsburgh, Pennsylvania. Westinghouse relaunched the station as KDKA on November 2, 1920, claiming to be "the world's first commercially licensed radio station". The commercial broadcasting designation came from the type of broadcast license; advertisements did not air until years later. The first licensed broadcast in the United States came from KDKA itself: the results of the Harding/Cox Presidential Election. TheMontreal station that became CFCF began broadcast programming on May 20, 1920, and the Detroit station that became WWJ began program broadcasts beginning on August 20, 1920, although neither held a license at the time. Radio Argentina began regularly scheduled transmissions from the Teatro Coliseo in Buenos Aires on August 27, 1920, making its own priority claim. The station got its license on November 19, 1923. The delay was due to the lack of official Argentine licensing procedures before that date. This station continued regular broadcasting of entertainment and cultural fare for several decades. Radio in education soon followed and colleges across the U.S. began adding radio broadcasting courses to their curricula. Curry College in Milton,...