Moorhead / De Forest type ER triode
date: label: date made
content: ca 1908
name: label: maker
content: De Forest Radio Telephone & Telegraph Co.
notes: label: Description (Brief)
content: Moorhead laboratories "Electron Relay" or ER tube. A 4-pin base with brass shell, plastic insulator. Dull-sheen anode. Tipped envelope, cork lead insulator, cylindrical collector, spiral grid, single-arch tungsten emitter. Printed on envelope: "Licensed for amateur or / experimental use only. / E.R. 537857"; stamped on base: "De Forest Audion / U. S. Patent No.s. 841387-879532 / Sold only for amateur / and experimental use"; also: "Marconi [globe logo] / Trade Mark / Fleming Pat [??] 8[?]3684". "S" molded on base insulator. Note on file reads: "Manufacture: Moorhead laboratories." Reference: Tyne, "Saga of the Vacuum Tube," page 174-176.
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
creditLine: label: Credit Line
content: from Dale F. Kelly
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.314244
label: catalog number
content: 314244
label: accession number
content: 195336
objectType: label: Object Name
content: Electron Tube, Triode
label: Object Name
content: triode
label: Other Terms
content: Electron Tube, Triode; Electron Tubes
physicalDescription: label: Measurements
content: overall: 4 in x 1 3/4 in; 10.16 cm x 4.445 cm