Amrad type S recitifer tube
date: label: date made
content: ca 1922
name: label: maker
content: American Radio & Research Corporation
notes: label: Description (Brief)
content: Amrad type S rectifier tube, mogul screw base with glass insulator, tipped S-shape envelope. Donor’s card reads: “Gaseous rectifier made by Amrad, the American Radio and Research Corporation of Medford Hillside, Mass., in the early 1920s. Mounted on a mogul screw thread base, this was the first commercially available gaseous rectifier without a filament and preceded the Raytheon type B rectifier by several years. Sold for $8.00 each in the 1920s. Rated at about 20 watts, functioning as half wave rectifiers on voltages from 300 to 750, they found some limited application in early amateur continuous wave transmitters. These tubes could be connected in parallel for additional current capacity and in series for use on higher voltage. Current was limited to about 50 milliamperes per tube.”
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.324433
label: catalog number
content: 324433
label: accession number
content: 252994
objectType: label: Object Name
content: Electron Tube, Diode
label: Object Name
content: rectifier
label: Other Terms
content: Electron Tube, Diode; Electron Tubes
physicalDescription: label: Measurements
content: overall: 4 3/4 in x 2 in; 12.065 cm x 5.08 cm