page_title: Charles E. Apgar
section_title: Amateur radio
hierarchical_section_title: Charles E. Apgar / Amateur radio
caption_attribution_description: English: Circuit diagram of amateur wireless station of Charles E. Apgar
context_page_description: Charles Emory Apgar was an American business executive and amateur radio operator. He is known for making early recordings of radio transmissions at the start of World War I. The recordings that he made of a wireless telegraphy station owned by a German Empire-based company operating from the United States were used to expose an espionage ring. They provided evidence of clandestine messages being sent in violation of a prohibition intended to maintain United States neutrality. This proof of illicit operation led to the government seizing control of the facility to stop the activity. Apgar's efforts received extensive coverage in newspapers and technical science magazines at the time. His contributions were praised by government investigators. Publications continued to remark on his work many years later.
context_section_description: Apgar became interested in wireless telegraphy after reading about an amateur who had heard election returns transmitted by a newspaper on election night (i.e. before the results could be widely distributed the following morning.) He built his first "home-made" wireless telegraphy equipment on December 11, 1910 – one month after the election. He listened to news bulletins from the New York Herald station OHX in Manhattan. The station had been created to send news to approaching ocean liners and receive reports about their voyage.
  After the passage of the Radio Act of 1912, he was licensed to use the call sign 2MM from 1913 to 1915. At the experimental wireless station inside his home in Westfield he operated a 450 watt amateur station. The equipment he constructed could use a wavelength of 8,000 metres (37 kHz) during an era when few amateurs went beyond 600 metres (500 kHz). It was described as a "high-grade plant" of "extraordinary efficiency." In April 1913 he became an associate member of the recently founded Institute of Radio Engineers. He was an early participant in the American Radio Relay League (ARRL) by October 1913. He soon began publishing descriptions of wireless equipment that he had designed in technical magazines.
  He built equipment that could greatly amplify the sound from his radio receiver. Connected to a device that he called a "loud talker-horn" (an early type of loudspeaker) it could be heard 600 feet (180 m) away. An editor of a magazine was so impressed that he enthusiastically described it as "One of the greatest feats ever produced by any amateur..." Apgar also devised a method to record the signals from stations that he listened to. His accounts of the equipment he used to make the recordings were featured in magazines such as The Wireless Age and Electrical Experimenter. His recordings were colloquially referred to as "canned messages."
caption: Circuit diagram of his station connected to a phonograph recorder.
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