Western Electric type 205D vacuum triode
date: label: date made
content: ca 1925
name: label: maker
content: Western Electric
notes: label: Description (Brief)
content: Donor card reads: "Triode made by Western Electric Company. Primarily an audio frequency amplifier of about 1 watt rating. Used by Western Electric in pre-amplifier of their AM broadcasting stations in the late 1920s. Used prior to that time as line amplifiers in telephony. Has the Western Electric special "Shaw" base. Not generally available for private use in the early days. Oxide coated filament, 4.5 volts at 1.6 amperes. As much as 350 volts could be used on the plate. A very satisfactory tube of its period, and for the purpose. From this design the VT-2 tube of World War 1 was developed."
label: Description (Brief)
content: A moderate power triode designed for use as an audio frequency amplifier, but could also be used as an radio frequency amplifier or oscillator. Eff = 4.5 volts; Ip = 1.6 amperes. Ep = 200 - 400 volts; Ip = 8 - 40 milliamps. Mu = 6.7 - 7.4; Rp = 3500 - 4800 ohms. Tyne notes that the locking pin on 205 type tubes was set 45o differently from other tubes to prevent low-power tubes from being inadvertently substituted. Reference: Tyne, "Saga of the Vacuum Tube," page 287.
label: Description (Brief)
content: "The No. 205D is a three-element filamentary type tube intended for use as a radio-frequency amplifier, oscillator, modulator, and audio-frequency amplifier in output stages when moderate powers are required." Reference: Western Electric 205D data sheet: https://www.westernelectric.com/s/205D.pdf.
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.324306
label: catalog number
content: 324306
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 1/4 in x 2 1/4 in; 10.795 cm x 5.715 cm