Charles David "Doc" Herrold (November 16, 1875 – July 1, 1948) was an American inventor and pioneer radio broadcaster, who began experimenting with audio radio transmissions in 1909. Beginning in 1912 he apparently became the first person to make entertainment broadcasts on a regular schedule, from his station in San Jose, California.
Early life
Born in Fulton, Illinois, Herrold grew up in San Jose. In 1895 he enrolled in Stanford University, where he studied astronomy and physics for three years, but withdrew due to illness and never graduated. While at Stanford he was inspired by reports of Guglielmo Marconi's demonstrations that radio signals could be used for wireless communication, and began to experiment with the new technology.
After recovering from his illness, Herrold moved to San Francisco, where he developed a number of inventions for dentistry, surgery, and underwater illumination. However, the April 18, 1906 San Francisco earthquake destroyed his work site and apartment. He next took an engineering teaching position for three years, at Heald's College of Mining and Engineering in Stockton, California. While there, his various research projects included the remote detonation of mines using radio signals. During this time he received further inspiration from the novel Looking Backward by Edward Bellamy, which foresaw the transmission of entertainment programming over telephone lines to individual homes. Herrold began to speculate about the possibilities of instead using radio signals to distribute the programming more efficiently.
The original spark-gap transmitters used for radio signalling could only transmit Morse code messages. Even with this limitation, there was some broadcasting by early radio stations, beginning in 1905 with daily noon time signals transmitted by U.S. Naval stations. Although these broadcasts generated interest among amateur radio operators, especially after they were expanded to include daily weather forecasts and news summaries, the need to learn Morse code greatly restricted potential audiences.
To realize his idea of distributing entertainment by radio, Herrold first needed to perfect a radiotelephone transmitter. He was not unique in this endeavor. Although he would later claim that only he had conceived of entertainment broadcasting, there were actually a few others who had speculated about the possibilities. On December 21, 1906, Reginald Fessenden demonstrated an alternator-transmitter of his own design, and one reviewer noted that it was "admirably adapted to the transmission of news, music, etc. as, owing to the fact that no wires are needed, simultaneous transmission to many subscribers can be effected as easily as to a few". However, Fessenden would almost exclusively focus on point-to-point transmissions intended to supplement the wire telephone system.
Lee de Forest was even more ambitious, although Herrold would later incorrectly assert that "Certainly de Forest had no thought of a broadcast". As early as June 1907, a review of de Forest's test of his version of a Valdemar Poulsen arc transmitter noted that "the inventor believes that by using four different forms of wave as many classes of music can be sent out as desired by the different subscribers". De Forest made a series of musical demonstrations from 1907 to 1910, although he would not actually begin regular broadcasts until 1916, when vacuum-tube transmitters became available.
Radio development pre-WWI
On January 1, 1909, Herrold opened the Herrold College of Wireless and Engineering, located in the Garden City Bank Building at 50 West San Fernando Street in San Jose, where a huge "umbrella-style" antenna was constructed atop the building. The college's primary purpose was to train radio operators, for handling communications aboard ship or staffing shore stations. Although he would never get a degree, Herrold became known as "Doc" as a sign of his student's respect. Ray Newby, just 16 years old, acted as his primary assistant. At the time Herrold began his work, there was no regulation of radio stations in the United States, and the station was identified by self-assigned call letters, including FN and SJN. Later the Radio Act of 1912 mandated the licensing of stations, and Herrold was issued a license for an Experimental station in late 1915, with the call sign 6XF.