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Description
This water-cooled microphone was invented by Charles "Doc" Herrold. Herrold was the first to broadcast radio entertainment and information for an audience on a regularly scheduled, pre-announced basis. In 1921 he received a license as KQW, in San Jose. In 1949 KQW became KCBS in San Francisco. According to an article by Mike Adams for Antique Radio Classified (June 1996), this microphone is mounted on a telephone base. Herrold was on the air between 1912 and 1917 using his own patented arc transmitter and several versions of a water-cooled, carbon-button microphone. Water cooling was necessary because of the high DC current present in the arc system. Herrold constructed and used his microphone some time between 1913 and 1915. His notarized, handwritten notes bear the date March 1913. The patent indicates he applied in January 1914, and was granted U.S. Patent 1,165,255 on December 21, 1915. He shared the patent credit with a student at his wireless college, Emile Portal. Herrold used his microphone for his broadcasts until the April 1917 wartime ban forced him to sign off. Adams disassembled this microphone while it was housed at the Foothill Electronics Museum and photographed the parts; a copy of this article and photographs is attached to the record as a PDF.
Type
image
Identifier
52EABF1A-D941-4462-9F16-211677271759 2003-1-506
Subject
Radio broadcasting--California--San Jose Inventions KQW (Radio station: San Jose, Calif.) Herrold, Charles
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