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File:Marconi radio lighthouse on Inchkeith Island 1925.jpg

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Summary

Description
English: An experimental rotating radio beacon for ships built by Guglielmo Marconi 1922 on Inchkeith Island in the Firth of Forth, UK. It consisted of two cylindrical parabolic antennas of tuned wires, back-to-back, 32 feet in height with a horizontal aperture of 43 feet, mounted on a rotating platform which turned at a constant rate. The concept was to create a radio version of a lighthouse, which emitted two beams 180° apart which slowly rotated. Vertical feed antennas at the focus of each paraboloid are driven by two 500 watt spark transmitters in a separate building. A contact system on the rotating platform switched the beams on and off to transmit numbers in Morse code indicating the bearing of the ship from the beacon. It was operated at various wavelengths between 4.25 and 6.25 meters (48 - 70.6 MHz). (more information in Marconi constant speed rotating beam beacons, nonstopsystems.com
Date
Source Retrieved from Wells, N. The Marconi Wireless Beam Reflector on Inchkeith in Engineering magazine, London, Engineering Ltd, Vol. 119, No. 3089, March 13, 1925, p.309, fig.1 on archive.org
Author N. Wells

Licensing

Public domain
This work is in the public domain in the United States because it was published (or registered with the U.S. Copyright Office) before January 1, 1929.

Public domain works must be out of copyright in both the United States and in the source country of the work in order to be hosted on the Commons. If the work is not a U.S. work, the file must have an additional copyright tag indicating the copyright status in the source country.
Note: This tag should not be used for sound recordings.PD-1923Public domain in the United States//commons.wikimedia.org/wiki/File:Marconi_radio_lighthouse_on_Inchkeith_Island_1925.jpg

Captions

Marconi radio beacon, Inchkeith Island 1925

Items portrayed in this file

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13 March 1925Gregorian

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Date/TimeThumbnailDimensionsUserComment
current20:16, 1 September 2024Thumbnail for version as of 20:16, 1 September 2024615 × 455 (86 KB)ChetvornoUploaded a work by N. Wells from Retrieved from [https://archive.org/details/sim_engineering_1925-03-13_119_3089/page/n3/mode/2up Wells, N. The Marconi Wireless Beam Reflector on Inchkeith in ''Engineering'' magazine, London, Engineering Ltd, Vol. 119, No. 3089, March 13, 1925, p.319, fig.1] on archive.org with UploadWizard

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