Western Electric model 7A audio amplifier
date: label: date made
content: c 1921
label: date made
content: ca 1921
name: label: maker
content: Western Electric
notes: label: Description (Brief)
content: Marked: "7A Amplifier / Western Electric / Licensed for use only as a part of / the Western Electric Loud Speaking / Telephone Outfit / Pat. in USA / Jan 15, 1907 / Feb 18, 1908 / Mar 2, 1915 [two patents] / July 3, 1917 / Aug 26, 1919 / Jan 27, 1920 / Aug 10, 1920 / Apr. 19, 1921 / Nov 29, 1921 / Patents Applied for / Made in U.S.A." Audio amplifier using three 216-A type tubes. Controls: output rheostat, filament switch, binding posts for input-output, 6 volt filament supply and 120V plate supply. (Tubes missing.) REF: "Clymer-Greenwood", page 162.
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
creditLine: label: Credit Line
content: from Franklin Wingard
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.320780
label: catalog number
content: 320780
label: accession number
content: 241556
objectType: label: Object Name
content: radio receiver
label: Object Name
content: audio amplifier
physicalDescription: label: Measurements
content: overall: 9 7/8 in x 12 1/2 in x 4 1/2 in; 25.0825 cm x 31.75 cm x 11.43 cm