Scanning the Past: A History of Electrical Engineering from the Past

Submitted by Dick Reiman, Historian

Copyright 1992 IEEE. Reprinted with permission from the IEEE publication, "Scanning the Past" which covers a reprint of an article appearing in the Proceedings of the IEEE Vol. 80, No. 12, December 1992.

Frank Conrad and Station KDKA

Seventy years ago this month, the PROCEEDINGS OF THE INSTITUTE OF RADIO ENGINEERS (IRE) included a paper by Frank Conrad on the design of radio receivers. He had recently been promoted to the position of Assistant Chief Engineer of the Westinghouse Electric and Manufacturing Company in Pittsburgh, Pennsylvania. He had worked for Westinghouse since 1890 and had been instrumental in starting the pioneering radio broadcasting station KDKA in1920.

In his paper Conrad discussed design features of receivers suitable for operation by those "entirely unfamiliar with the techniques of radio apparatus." He recommended use of a regenerative vacuum-tube circuit because of its sensitivity and simple tuning. However, he noted that one significant defect of the regenerative receiver was the interference which it could produce in other nearby receivers due to radiation from the oscillator. He also stressed the importance of having a good antenna and a source of power which did not require frequent attention.

Conrad was born in Pittsburgh in 1874, the son of a railroad mechanic. Conrad's formal education ended when he completed the 7th grade and he went to work in the shops of the Westinghouse Company at age 16. In 1897 he joined the Westinghouse Testing Department, where he demonstrated inventive ability through patented inventions, including a watt-hour meter and an automobile electrical system. He was to receive more than 200 patents during his long career. By 1912, he became an amateur radio enthusiast and constructed a receiver to monitor Navy time signals. In 1916 he received a license to operate a radio transmitter designated as station 8XK from his home, and he was permitted to use the station to test military radio apparatus after the government suspended amateur radio operation in April 1917 because of the war. He did important work on radio equipment for the Army Signal Corps during World War I, including sets for installation in aircraft. He joined the IRE in 1917 and became a Fellow of the Institute in 1927.

Conrad resumed operation of his amateur radio station in 1919 and began to broadcast music from phonograph records on a regular basis. Reportedly he was not very fast at using Morse code, and he decided that the use of a microphone would speed up his communication with other amateurs. His music programming proved unexpectedly popular and caught the attention of Harry P. Davis, a Westinghouse vice-president, who foresaw a potential consumer market for radio receivers. Davis arranged for a transmitter designed by Conrad to be installed at the Westinghouse plant. The station was licensed as KDKA, and it broadcast, with a power of about 100 watts, election returns during the evening of November 2, 1920. The transmitter power was raised to 1000 watts in October 1921, and it was reported that the station could be heard over much of the United States and in Europe at night under favorable conditions. By then the radio broadcasting industry had achieved an astonishing rate of growth, and there were more than 500 commercial stations on the air in the United States by the end of 1922. During the 1920's Conrad turned his attention to short-wave radio and published another IRE paper in October 1924 in which he reported promising results at wavelengths down to 60 meters.

Conrad received the Morris N. Liebmann award from the IRE in 1925 and the Edison Medal from the American Institute of Electrical Engineers in 1930. He retired in 1940 and died during a trip to Florida in December 1941.

James E. Brittain
School of History, Technology, and Society
Georgia Institute of Technology