File:Marconi crystal radio receiver.jpg
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Marconi_crystal_radio_receiver.jpg (754 × 552 pixels, file size: 134 KB, MIME type: image/jpeg)
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[edit]DescriptionMarconi crystal radio receiver.jpg |
English: Marconi type 103 crystal radio receiver, used with the Marconi company's spark transmitter systems during the pioneering wireless telegraphy era of radio around 1920. The cat's whisker detector is visible at top. This radio used an inductively-coupled antenna transformer circuit, which improved the selectivity (Q factor) of the receiver, allowing interfering stations near the desired station to be rejected. The "short wave condenser" tuned the primary coil, the "intermediate condenser" tuned the secondary. The "aerial tuning inductance" knob selected taps on the coil winding to adjust the impedance match between the antenna and the receiver. The "Billi condenser" was a decoupling capacitor across the earphone leads, which smoothed the audio signal from the detector, removing the residual RF carrier pulses. The "potentiometer" applied an adjustable bias voltage from a battery across the detector, to make it more sensitive. |
Date | |
Source | Downloaded 2010-03-15 from Elmer Eustice Bucher (1917) How to Pass U.S. Government Wireless License Examinations, 4th Ed. revised, Wireless Press, Inc., New York, p.68 on Google Books |
Author | Elmer Eustice Bucher |
Permission (Reusing this file) |
Public Domain in USA - published prior to 1923 in USA |
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[edit]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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Date/Time | Thumbnail | Dimensions | User | Comment | |
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current | 15:08, 3 May 2021 | 754 × 552 (134 KB) | Materialscientist (talk | contribs) | FFT | |
06:28, 17 May 2010 | 754 × 552 (74 KB) | Chetvorno (talk | contribs) | {{Information |Description={{en|Marconi type 103 Wikipedia:crystal radio receiver}} |Source=Downloaded 2010-03-15 from [http://books.google.com/books?id=avXNAAAAMAAJ&pg=PA68 Elmer Eustice Bucher (1917) ''How to Pass U.S. Government Wireless Lice |
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