File:Fessenden synchronous spark transmitter.jpg
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DescriptionFessenden synchronous spark transmitter.jpg |
English: The first spark-gap radio transmitter using a synchronous rotary spark gap, built by Canadian engineer Reginald Fessenden 28 December 1905 at his laboratory at Brant Rock, Massachusetts, USA. With this transmitter on 10 January 1906 Fessenden achieved the first two-way transatlantic radio communication, exchanging wireless telegraphy messages in Morse code at a frequency of about 88kHz with an identical station in Machrihanish, Scotland (Guglielmo Marconi, Fessenden's rival, who made the first transatlantic contact in 1901, had only been able to make one-way transmissions). The transmitter was powered by a 40 hp steam engine turning a 125 Hz 35 kVA alternator (AC generator) (in foreground) whose output current was stepped up by a transformer to thousands of volts. This powered a tuned circuit consisting of a capacitor and air core coil through the rotary spark gap (visible), consisting of a wheel with 50 electrodes on its rim which passed by a stationary electrode. The sparks excited oscillating radio frequency currents in the tuned circuit which were applied to the antenna through a secondary coil coupled to the first. Fessenden's machine had two advantages:
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Date | |
Source | Retrieved 13 October 2013 from Jonathan Adolf Wilhelm Zenneck 1915 Wireless Telegraphy, McGraw-Hill Book Co., New York, p. 205, fig. 251 on Google Books |
Author | Jonathan Adolf Wilhelm Zenneck |
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current | 12:32, 3 May 2021 | 1,956 × 1,335 (591 KB) | Materialscientist (talk | contribs) | FFT | |
21:40, 15 October 2013 | 1,956 × 1,335 (308 KB) | Chetvorno (talk | contribs) | User created page with UploadWizard |
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