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File:Ship spark transmitter tuned circuit 1921.jpg

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Description
English: The tuned circuit of a marine spark gap transmitter, an obsolete radio transmitter used during the wireless telegraphy era, 1890-1920. This was from a German Telefunken Type D 1.5 kW ship wireless set, which could transmit on wavelengths of 600 - 200 meters (500 - 1500 kHz). It consists of a bank of Leyden jar capacitors (cylinders) connected to a spiral inductor of copper strip through a quenched spark gap (top). It was powered with an alternating current of 10-20 kilovolts from a high voltage transformer.

Alterations to image: partially removed aliasing artfacts (crosshatched lines) introduced by scanning the halftone photo using Gimp FFT filter.

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Date

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Source Retrieved August 4, 2013 from Bernard John Leggett (1921) Wireless Telegraphy, with Special Reference to the Quenched-Spark System, E. P. Dutton and Co., New York, fig. 29a facing p. 85 on Google Books
Author Bernard John Leggett

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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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This image might not be in the public domain outside of the United States; this especially applies in the countries and areas that do not apply the rule of the shorter term for US works, such as Canada, Mainland China (not Hong Kong or Macao), Germany, Mexico, and Switzerland. The creator and year of publication are essential information and must be provided. See Wikipedia:Public domain and Wikipedia:Copyrights for more details.
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Date/TimeThumbnailDimensionsUserComment
current11:43, 3 May 2021Thumbnail for version as of 11:43, 3 May 2021852 × 1,128 (223 KB)MaterialscientistFFT
09:17, 1 November 2015Thumbnail for version as of 09:17, 1 November 2015852 × 1,128 (117 KB)ChetvornoUser created page with UploadWizard

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