File:Homemade push-pull 809 triode CW amateur radio transmitter 1937.jpg
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Captions
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Homemade 1937 radiotelegraph transmitter
Summary[edit]
| Description |
English: A homemade vacuum tube shortwave radiotelegraph amateur radio transmitter from 1937. It uses two 809 triode tubes in a push-pull output circuit to produce 120 watts power on 80, 40, 20, or 10 meter shortwave amateur frequency bands. |
| Date | |
| Source | Retrieved 7 June 2023 from Smith, W. W. 1938 The Radio Handbook, Radio Ltd., Los Angeles, p.332, fig.7 on archive.org website |
| Author | Smith, W. W. |
| Permission (Reusing this file) |
This book published in the US in 1938 would have the copyright renewed in 1966. Online page scans of the Catalog of Copyright Entries, published by the US Copyright Office can be found here [1]. Search of the Renewals for Periodicals for 1965, 1966 and 1967 show no renewal entries for The Radio Handbook. Therefore the work's copyright was not renewed and it is in the public domain. |
Licensing[edit]
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This work is in the public domain because it was published in the United States between 1929 and 1963, and although there may or may not have been a copyright notice, the copyright was not renewed. For further explanation, see Commons:Hirtle chart and the copyright renewal logs. Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (70 years p.m.a.), Mainland China (50 years p.m.a., not Hong Kong or Macao), Germany (70 years p.m.a.), Mexico (100 years p.m.a.), Switzerland (70 years p.m.a.), and other countries with individual treaties.
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| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 17:06, 12 June 2023 | | 654 × 650 (125 KB) | Chetvorno (talk | contribs) | Uploaded a work by Smith, W. W. from Retrieved 7 June 2023 from [https://archive.org/details/The_Radio_Handbook_5th_edition_-_Smith_Dawley_1938/page/332/mode/2up Smith, W. W. 1938 ''The Radio Handbook'', Radio Ltd., Los Angeles, p.332, fig.7] on archive.org website with UploadWizard |
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