File:Carborundum crystal detector.png
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DescriptionCarborundum crystal detector.png |
English: A carborundum crystal detector, a device used in wireless receivers and later crystal receivers from about 1906 to the 1920s. It consists of a crystalline pebble of carborundum (silicon carbide) held in a metal cup, with a metal contact pressed against its surface by the thumbscrew (center). 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 signal. 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. |
Date | |
Source | Downloaded 2010-05-28 from Percy W. Harris (1922) Crystal Receivers for Broadcast Reception, Wireless Press, New York, p. 40, fig. 52 on Google Books |
Author | Percy W. Harris |
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Public domainPublic domainfalsefalse |
This media file is in the public domain in the United States. This applies to U.S. works where the copyright has expired, often because its first publication occurred prior to January 1, 1929, and if not then due to lack of notice or renewal. See this page for further explanation.
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This image might not be in the public domain outside of the United States; this especially applies in the countries and areas that do not apply the rule of the shorter term for US works, such as Canada, Mainland China (not Hong Kong or Macao), Germany, Mexico, and Switzerland. The creator and year of publication are essential information and must be provided. See Wikipedia:Public domain and Wikipedia:Copyrights for more details.
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current | 02:17, 30 November 2011 | 1,212 × 708 (93 KB) | Chetvorno (talk | contribs) |
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Horizontal resolution | 28.35 dpc |
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Vertical resolution | 28.35 dpc |
File change date and time | 09:09, 28 May 2010 |
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1922
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b74258b02bf8e20199e0cf822784df550ff32095
94,862 byte
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