Western Electric type 221D triode
date: label: date made
content: ca 1927
name: label: maker
content: Western Electric
notes: label: Description (Brief)
content: Plastic 4-pin base with tipped S-shaped envelope. A general purpose tube designed for Bell affiliate, Northern Electric of Canada; similar to the UV201A. Donor’s card reads: “Triode made by Western Electric Company in the late 1920s. Oxide coated filament: 5.25 volts at .25 ampere, 135 volts on the plate, 9 volt negative control grid bias. Amplification factor 9.” See also: Tyne, "Saga of the Vacuum Tube," pages 295-297.
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
creditLine: label: Credit Line
content: from Paul G. Watson
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.324796
label: catalog number
content: 324796
label: accession number
content: 252994
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 1/2 in x 1 3/4 in; 11.43 cm x 4.445 cm