File:Toroidal telephone loading coil.jpg

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Summary

Description
English: A loading coil for a 1922 AT&T long distance telephone trunkline between New York and Chicago. It consists of a toroidal iron core with two 0.175 H windings. Each twisted pair in the telephone trunkline is attached to a loading coil. The coils are contained in steel tanks on the telephone pole, immersed in oil. The line required a loading coil every 6000 ft.
Date
Source Retrieved February 21, 2014 from James J. Pilliod, "Philadelphia-Pittsburgh section of the New York-Chicago cable" in Transactions of the AIEE, American Institute of Electrical Engineers, New York, August 1922, p. 452, fig. 18 on Google Books
Author James J. Pilliod

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Public domain
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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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United States
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August 1922Gregorian

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current16:09, 3 May 2021Thumbnail for version as of 16:09, 3 May 2021827 × 816 (138 KB)wikimediacommons>MaterialscientistFFT

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