File:Carborundum detector 1911.jpg
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Carborundum_detector_1911.jpg (235 × 171 pixels, file size: 10 KB, MIME type: image/jpeg)
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An antique carborundum crystal radio detector from 1911
Summary
[edit]DescriptionCarborundum detector 1911.jpg |
English: A carborundum crystal detector, a device used as a demodulator in crystal radio receivers from about 1906 to the 1920s. This 1911 example was sold to hobbyists and radio amateurs in the back of American radio magazines for a price of 50 cents. It consists of a crystalline pebble of silicon carbide (then called carborundum) clamped between two electrical contacts. It was a crude semiconductor diode, conducting electric current in one direction but not in the opposite direction. In a radio receiver its function was to rectify the radio signal, extracting the audio (sound) signal from the radio frequency carrier wave. Because of the heavier construction of carborundum detectors, which didn't require a delicate "cat's whisker" contact like other crystal detectors, they were used in shipboard and military radio receivers where vibration could be expected. Carborundum detectors required a forward bias voltage of a few volts applied across the crystal by a battery and potentiometer. |
Date | |
Source | Retrieved 30 October 2015 from Modern Electrics magazine, Modern Electrics Publication Co., New York, Vol. 4, No. 3, June 1911, p. 190 on americanradiohistory.com |
Author | Unknown authorUnknown author |
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[edit]Public domainPublic domainfalsefalse |
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This work is in the public domain in the United States because it was published (or registered with the U.S. Copyright Office) before January 1, 1929.
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Note: This tag should not be used for sound recordings.PD-1923Public domain in the United States//commons.wikimedia.org/wiki/File:Carborundum_detector_1911.jpg |
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current | 22:02, 5 July 2018 | ![]() | 235 × 171 (10 KB) | Chetvorno (talk | contribs) | User created page with UploadWizard |
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1 June 1911Gregorian
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fa4788b0d15de2235d931165c1b3ffd0f1dc8424
9,978 byte
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