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Mechanical Television Broadcasting in the United States (1928-1939)
The photograph above shows Miss Sue Weman in a live mechanical
television broadcast, on May 4th, 1931. She stands in front of a WGBS
microphone, with two banks of photocells on each side, while the Jenkins
flying-spot scanner peeks through a hole in the wall behind her. Early History of WGBS WGBS began broadcasting on October 24, 1924, on 950 AM, in New York city, and was owned by the Gimbel Brothers Department Store. WGBS is believed to be the first radio broadcaster to originate a program from an airplane. On October 10, 1931, WGBS was sold to William Randolph Hearst, who in January 1932, changed the call letters to WINS, which stood for Hearst's International News Service, then one of the nation's three major wire services. During the period early part of 1931, but before the call letters were changed to WINS, the station began experimenting with mechanical television broadcasting, operating a Jenkins mechanical scanner through the experimental transmitter, W2XCR. The station used both 48-line / 15 FPS, and 60-line / 20 FPS standards during 1931. In July 1932, WINS moved out of the old WGBS studios in the Hotel Lincoln to a Park Avenue locale at 110 E. 58th St., the Ritz Tower.
Later History WINS switched to 1010 AM on October 30, 1943. Hearst sold WINS for $2 million in 1946, to the Crosley Broadcasting Corporation In August 1957, WINS moved its studios to 7 Central Park West On April 19, 1965, the station went to an all-news format.
Technical Explanation of Mechanical TV Frequencies - Courtesy Steve McVoy Mechanical TV broadcast in the AM radio band (550-1600 kHz) in
1928 and 29. With 24 and 30 line systems, only about 10 kHz of bandwidth was
needed, so standard radio channels could be used. Some stations also broadcast
in the shortwave band. Beginning in 1930, the 2-3 mHz band was used for
television, with 100 kHz channel width. 60 line systems required about 40 kHz of
bandwidth. TV broadcasts could be identified by their distinctive sound. |