National Radio Tube type R-3 "Rectobulb"
date: label: date made
content: ca 1930
name: label: maker
content: National Radio Tube Company
notes: label: Description (Brief)
content: National Radio Tube type R-3 Rectobulb. Marked: "National Radio / Tube Co." and "Choke input / to filter / must be used / with all / Rectobulbs." Label near pin-base: "Cathode [down arrow]". Base stamped: "National / R-3 / Rectobulb", and "Licensed only to extent indicated on carton". A double-ended rectifier tube with a 4-pin base including filament connections on one end, and a plate lead on top. Unit has a metal mesh anode. Pin base has been re-glued onto envelope. Made by National Radio Tube Company, San Francisco. Reference: Tyne, "Saga of the Vacuum Tube," page 359; and 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
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: ZZ.RSN80594U01
objectType: label: Object Name
content: Electron Tube, Diode
label: Object Name
content: rectifier
label: Other Terms
content: Electron Tube, Diode; Electron Tubes
physicalDescription: label: Physical Description
content: composition (overall material)
label: Physical Description
content: glass (overall material)
label: Physical Description
content: metal (overall material)
label: Measurements
content: electron tube, diode: 8 1/2 in x 3 in; 21.59 cm x 7.62 cm