File:Leaf spring crystal detector.png
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Leaf_spring_crystal_detector.png (423 × 344 pixels, file size: 16 KB, MIME type: image/png)
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Summary
[edit]DescriptionLeaf spring crystal detector.png |
English: A precision type of crystal detector, from an illustration in a 1919 radiotelegraphy book. It incorporated a needle that touched the surface of a semiconducting mineral crystal. The contact had to be adjusted before each use, and was very sensitive to the position and pressure of the wire on the crystal. This example had a leaf spring adjusted by a micrometer screw to control the pressure. The crystal is secured in a metal cup with a setcrew. |
Date | |
Source | Downloaded 2010-05-26 from Cyril Methodius Jansky (1919) Principles of Radiotelegraphy, 1st Ed., McGraw-Hill, New York, p. 204, fig. 139 on Google Books. |
Author | Unknown authorUnknown author |
Permission (Reusing this file) |
Public domain in USA - published prior to 1923 in USA |
Licensing
[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 | 08:28, 26 May 2010 | 423 × 344 (16 KB) | Chetvorno (talk | contribs) | {{Information |Description={{en|A Wikipedia:Cat's whisker detector, an antique electronic component used in Wikipedia:crystal radios during the first decades of the 20th century. This example is a precision leaf spring type from an illustration |
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Horizontal resolution | 28.35 dpc |
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Vertical resolution | 28.35 dpc |
File change date and time | 18:55, 25 May 2010 |