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Description: | ordinary nickel sheath Fleming Gimingham exhaust ( visible under Uv on paper tag removed ) III (in pencil on reverse of same tag) MANU Unsigned. 1907 DES FOREST,Lee,de 1907 United States of America This is a triode valve designed by Lee de Forest and described in his patent application filed in January 1907. However, it is not a production model. This specimen has the grid and hot filament in a nickel tube closed at it's upper end. It is not like the production model from 1908 but is of the same size and construction as the one which belonged to Sir John Ambrose Fleming dated 1907 and fig'd, 1954, Institute of Electrical engineers, Thermionic Valves 1904-1954, p. 40, see catalogue item no. 2 on page 43. The tube was evacuated using combination a mechanical and mercury pump invented in 1882. | License: | http://www.hmag.gla.ac.uk/spirit/rights/ | Publisher: | Hunterian Museum and Art Gallery, University of Glasgow | Rights holder: | Hunterian Museum and Art Gallery, University of Glasgow | Subjects: | SCIENTIFIC COLLECTION : | Source: | Hunterian Museum | Creator: | Hunterian Museum and Art Gallery, University of Glasgow | Identifier: | http://www.huntsearch.gla.ac.uk/cgi-bin/... | Language: | en-GB | Go to resource |
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