General Electric / RCA type 860 power tetrode
date: label: date made
content: ca 1930
name: label: maker
content: General Electric Company
notes: label: Description (Brief)
content: A screen grid radio frequency power amplifier, transmitting tetrode for very high frequency use. Air cooled. A 4-pin ceramic base with one braided copper lead on top and another on the side. G-shaped envelope. Marked: "408" on stem press. Amplification factor: 200; transconductance 1100 microhms. Donor’s card reads: “Power tetrode made by the General Electric Company for the Radio Corporation of America in the late 1920s or early 1930s for use as a high frequency (up to 30 megacycles) oscillator or amplifier. Used by AM broadcast stations in their short wave transmitters and by amateurs. The 860 followed by some months the 852 triode of the same design and as the first of its type, a screen grid of moderate capacity for the then new high frequency broadcasters. Thoriated tungsten filament: 10 volts at 3.25 amperes. For Class C radio frequency operation, 3000 volts on the plate, 300 on the screen, 150 volts negative control grid bias, 7 watts drive for an output of 165 watts. Made by GE beginning in 1929 primarily to eliminate the neutralizing difficulties encountered in quick frequency shift transmitters for the military.” See also: https://www.radiomuseum.org/tubes/tube_860.html.
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.324548
label: catalog number
content: 324548
label: accession number
content: 252994
objectType: label: Object Name
content: Electron Tube
label: Object Name
content: tetrode
label: Other Terms
content: Electron Tube; Electron Tubes
physicalDescription: label: Measurements
content: overall: 8 1/2 in x 5 1/4 in x 3 3/4 in; 21.59 cm x 13.335 cm x 9.525 cm