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Summary
| Description |
English: High Q plug-in inductor from 1937 used in tuned circuits of shortwave radio transmitters. Amateur radio transmitters of this era used tuned circuits, not quartz crystals, to control the radiated frequency. The coil plugged into a jack in the transmitter amplifier, so the frequency band could be changed by exchanging the coil with one of a different inductance. It shows high Q construction: a single layer winding is used with the turns spread apart, to reduce proximity effect losses; it is made of thick silver plated wire to reduce skin effect losses, and instead of a coil form is suspended by thin insulating strips to reduce dielectric losses. |
| Date | |
| Source | Retrieved 2 November 2015 from Short Wave and Television magazine, Popular Book Corp., Mount Morris, IL, April 1937, p.744 on worldradiohistory.com website |
| Author | Unknown author |
Licensing
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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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File history
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| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 16:33, 12 June 2023 | | 330 × 240 (23 KB) | Chetvorno | Uploaded a work by Unknown from Retrieved 2 November 2015 from [https://worldradiohistory.com/Archive-Short-Wave-Television/30s/SW-TV-1937-04.pdf ''Short Wave and Television'' magazine, Popular Book Corp., Mount Morris, IL, April 1937, p.744] on worldradiohistory.com website with UploadWizard |
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