AM RADIO, THE EARLY DAYS

by R. J. Reiman, Historian

Where and when were the first radio broadcasts? Credit for this goes to the Westinghouse station KDKA in Pittsburgh for its broadcast of the Harding-Cox presidential election returns on November 2, 1920.

The idea for the broadcast was developed by Frank Conrad, a Westinghouse engineer, who had been transmitting opera music and announcing its source over his amateur station. To his surprise, Conrad received a deluge of letters from his fellow amateurs, acknowledging that they had heard his transmission. Conrad contacted Henry P. Davis, a Westinghouse Vice-President, about the experience. Davis concluded that regularly scheduled broadcasts would stimulate the sales of Westinghouse amateur receivers. He obtained a license from the Department of Commerce to operate an experimental station on 833 kHz, a frequency below the band allocated for amateur use, and he gave Conrad corporate financial support to build and operate a station at the Westinghouse plant. Conrad employed electron tube technology to generate the transmitted signal and thus achieved broadcast quality. The broadcast of the election returns was heavily promoted in the newspapers and thousands of amateurs were able to receive it.

KDKA's claim to be first to broadcast was challenged, as there were other broadcasts intended for a group of listeners. Fessenden had broadcast from his Brant Rock Station in 1906, to ships at sea,and DeForest had broadcast from the Eiffel Tower in 1908. The 1920 election was also broadcast from station 8MK installed at Detroit News, and David Sarnoff preceded Davis in conceiving the potential of radio to reach a mass audience for commercial purposes. Fessenden and DeForest used spark transmitters for broadcasting with corresponding inferior quality. The KDKA broadcast was the direct ancestor of modern broadcasting.

David Sarnoff's concept of reaching a mass radio audience was documented in a memo in 1915 to RCA President Edward J. Nally. His plan was to transmit music by wireless waves with receivers tuned to the transmitting wavelength. The receiver would consist of a "Radio Music Box" arranged

for several wavelengths, these changeable by a single switch, with both amplifying tubes and a speaker mounted in a single box. The box would compete for audience use with the piano and the phonograph. After the success of the first KDKA broadcast, Sarnoff appealed to Owen D. Young,

RCA's Chairman, to do a similar broadcast,with a borrowed GE transmitter, of the Dempsey-Carpentier World Heavyweight fight. The fight was held on an extremely hot day and both the fight (Demsey knocked out Carpentier) and the transmitter only lasted four rounds. The broadcast was a huge success with an estimated audience of 300,000 people, mostly amateur radio hams. Radio broadcasting was born, with RCA as one of the leaders.