File:Wire antenna insulator - Rugby Radio Station UK 1938.jpg
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Summary
| Description |
English: A electric insulator supporting the VLF wire antenna at the British government Rugby Radio Station, Rugby, UK in 1938. The station, completed in 1926, was a longwave VLF transatlantic wireless telegraphy station transmitting telegram traffic at a frequency of 16 kHz at output powers up to 500 kW. The antenna consisted of 16 820 ft steel masts supporting a 3 mile cage wire aerial consisting of 8 wires held apart in a circular "cage" shape by metal hoop spreaders. The end of one is visible in the picture. The insulator had to be long to withstand the 165,000 volt potential on the antenna. The wire loop around the end of the insulator is called a grading ring and reduces the potential gradient at the high voltage end of the antenna to discourage arcing. |
| Date | |
| Source | Retrieved November 6, 2015 from Electronics magazine, McGraw-Hill Publishing Co., New York, Vol. 11, No. 4, April 1938, cover on http://www.americanradiohistory.com |
| Author | Unknown author |
| Permission (Reusing this file) |
This 1938 issue of Electronics magazine 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. Search of the Renewals for Periodicals for 1965, 1966, and 1967 show no renewal entries for Electronics. Therefore the copyright was not renewed and it is in the public domain. |
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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| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 10:15, 7 November 2015 | | 640 × 766 (80 KB) | Chetvorno | User created page with UploadWizard |
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