National "Recto-bulb" rectifier tube
date: label: date made
content: ca 1920
name: label: maker
content: National Radio Co.
notes: label: Description (Brief)
content: A double-ended rectifier with a plastic 4-pin base and a top cap with a contact screw. BT-shaped envelope. Stamped on base: “National / Recto-Bulb.” Donor’s card reads: “Diode made by the National Company shortly after World War 1. A filament type high vacuum rectifier, half wave, for the plate supply in amateur transmitters. Except for filament life, these tubes were very satisfactory up to 1500 volts and 150 milliamperes DC output.” See also: https://www.radiomuseum.org/tubes/tube_r3_rectobulb.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.324417
label: catalog number
content: 324417
label: accession number
content: 252994
objectType: label: Object Name
content: Electron Tube, Diode
label: Object Name
content: diode
label: Object Name
content: rectifier
label: Other Terms
content: Electron Tube, Diode; Electron Tubes
physicalDescription: label: Measurements
content: overall: 8 in x 3 in; 20.32 cm x 7.62 cm