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File:Antenna tuning coil - station WOR.jpg

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Antenna_tuning_coil_-_station_WOR.jpg (277 × 415 pixels, file size: 27 KB, MIME type: image/jpeg)

Summary

Description
English: An antenna tuning inductor on the output stage of the transmitter of AM radio station WOR (AM) in New York City in 1935, which broadcast on 710 kHz at a power of 50 kW. From an advertisement in an electronics magazine. It shows typical construction used in high Q high power radio frequency coils. Since radio frequency currents flow on the surface of conductors due to skin effect, to reduce resistance the coil is made of large surface area copper tubing. To reduce proximity effect losses the windings consist of a single layer, with the turns spaced apart. To reduce dielectric losses the coil is suspended in air, supported by thin ceramic insulator strips.
Date
Source Retrieved November 6, 2015 from Electronics magazine, McGraw-Hill Publishing Co., New York, Vol. 8, No. 9, September 1935, p. 45 on http://www.americanradiohistory.com
Author Unknown authorUnknown author
Permission
(Reusing this file)
This image is from an advertisement without a copyright notice published in a 1935 US magazine. In the United States, advertisements published in collective works (magazines and newspapers) are not covered by the copyright notice for the entire collective work. (See U.S. Copyright Office Circular 3, "Copyright Notice", page 3, "Contributions to Collective Works".) Since the advertisement was published before 1978 without a copyright notice, it falls into the public domain.

Licensing

This work is in the public domain in the United States because it was published in the United States between 1929 and 1977, inclusive, without a copyright notice. For further explanation, see Commons:Hirtle chart as well as a detailed definition of "publication" for public art.

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Captions

An antenna tuning inductor

Items portrayed in this file

depicts

September 1935

image/jpeg

4e29f62ba928aa72b7dd28b728b6743915ffc1e5

28,042 byte

415 pixel

277 pixel

File history

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Date/TimeThumbnailDimensionsUserComment
current07:36, 14 July 2016Thumbnail for version as of 07:36, 14 July 2016277 × 415 (27 KB)ChetvornoUser created page with UploadWizard

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