De Forest type 20 "Audion" triode
date: label: date made
content: ca 1920
name: label: maker
content: De Forest Radio Telephone & Telegraph Co.
notes: label: Description (Brief)
content: De Forest type 20 "Audion" triode. Nickel-plated brass base with 4 pins, wooden insulator, tipped T-shaped glass envelope. No getter stain. Stamped on base shell: "De Forest Audion / U.S. Patent Nos. 841387-879532 / Sold only for amateur / and experimental use." Penciled on base: "Harley / RB"
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
creditLine: label: Credit Line
content: from Marshall N. Waterman, Frances Waterman and Ruth Waterman Ritch
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.313465
label: catalog number
content: 313465
label: accession number
content: 187068
objectType: label: Object Name
content: Electron Tube
label: Object Name
content: triode
label: Other Terms
content: Electron Tube; Electron Tubes
physicalDescription: label: Measurements
content: overall: 3 3/8 in x 1 3/8 in; 8.5725 cm x 3.4925 cm