French type TM "Metal" triode
date: label: date made
content: ca 1918
name: label: maker
content: Compagnie Generale des Lamps
notes: label: Description (Brief)
content: A 4-pin brass base (banana pins) with ceramic insulator, horizontal collector assembly, tipped G-shaped envelope. Appears similar to British type R valves. Written on press: "36" and "P 11". Stamped on envelope: "Metal"; on base: "G", "F", "P", "F". The word "metal" refers, in part, to the filament in the tube. Tungsten filaments for lamps and tubes were relatively new at the time, so the maker was letting potential buyers know that the tube has a metal rather than a carbon filament. In this case it also indicates the maker, the Compangnie Generale des Lamps, in Ivry, France. According to Gerald Tyne ("Saga of the Vacuum Tube," 192-196) the small company in Lyon that initially made these tubes couldn't keep up with war-time demand. The larger CGL "was pressed into service". He reports that over 100,000 of these tubes were made during the war. See also page 18 for confusion about the nomenclature of type S (erroneous) and type TM (correct).
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.322806
label: catalog number
content: 322806
label: accession number
content: 250988
objectType: label: Object Name
content: Electron Tube, Triode
label: Object Name
content: triode
label: Other Terms
content: Electron Tube, Triode; Electron Tubes
physicalDescription: label: Measurements
content: overall: 4 1/4 in x 2 in; 10.795 cm x 5.08 cm