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File:Triode tube 1906.jpg

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English: A De Forest audion tube, the first electron tube that could amplify. The first triode, or tube with three electrodes, a filament, grid, and plate, the audion was invented in 1906 by American engineer Lee De Forest. The top metal electrode is the plate. The bent metal wire partly visible under it is the grid. The filament was originally under that, attached to the wires at left, but has burned out. The filament wires were attached to the screw terminal at left, while the grid and plate terminals were brought out to the two wires at right. Tube belongs to History of San Jose, Perham Collection of Early Electronics.
Date 2006:11:12 21:47:31 GMT
Source Photo by uploader, taken at The History of Audio: The Engineering of Sound, an exhibition of the San Francisco Airport Museums in SFO Airport, Terminal 3 from 2006-09 to 2007-05.
Author Gregory F. Maxwell <> PGP: 0xB0413BFA
( Reusing this file)


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