File:Audion vacuum tube advertisement.png

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Original file (1,108 × 751 pixels, file size: 251 KB, MIME type: image/png)

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Description
English: Advertisement for the Audion vacuum tube invented by Lee De Forest in 1907, from The Electrical Experimenter magazine, August 1916, volume 4, number 4, page 228. This was the first triode, the first vacuum tube that could amplify electrical signals. It was used by amateur experimenters as well as commercial companies to build the first amplifying radio receivers, as indicated in the advertisement. By the time of this advertisement, improved versions were being sold by General Electric and other manufacturers, as shown by De Forest's efforts to differentiate his product.
Date Magazine published August 1916; this page scanned February 2008.
Source
English: The Electrical Experimenter magazine, August 1916, volume 4, number 4, page 228. This page was scanned by Swtpc6800 on an Epson Perfection 1240U at 300 dpi with half-tone de-screening enabled, and stored as an TIFF. The image was cropped and touched up in Adobe Photo Elements 5.0. This copy was saved as a 150-dpi PNG file.
Author Published by Experimenter Publishing Company Inc,. 233 Fulton Street, New York, N.Y. Hugo Gernsback, President; Sidney Gernsback, Treasurer; Milton Hymes, Secretary.
Permission
(Reusing this file)		 This magazine was published in the United States before 1923 and is in the public domain.
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: Electrical Experimenter Aug 1916 pg 228.png
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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:Audion_vacuum_tube_advertisement.png

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Date/TimeThumbnailDimensionsUserComment
current23:27, 11 January 2013Thumbnail for version as of 23:27, 11 January 20131,108 × 751 (251 KB)Chetvorno (talk | contribs)Cropped out everything but the De Forest Audion ad; this is the important content. The other stuff made the Audion ad too small to read.
22:07, 17 February 2008Thumbnail for version as of 22:07, 17 February 20081,275 × 1,650 (1.13 MB)Swtpc6800 (talk | contribs)== Summary == {{Information | Description= ''The Electrical Experimenter'', August 1916. | Source=This page was scanned by User:Swtpc6800 on an Epson Perfection 1240U at 300 dpi with half-tone de-screening enabled and stored as TIFF. The image was cr

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