RCA type UX-225 experimental "Radiotron" triode
date: label: date made
content: ca 1926
name: label: maker
content: Radio Corporation of America
notes: label: Description (Brief)
content: A plastic 5-pin base with tipless S-shaped envelope. Stamped on base: "Radiotron / UX-225". Donor's card reads: "Triode made by the Radio Corporation of America in the 1920s. An experimental model that never went into production, leading to the ultimate type 227 heater triode. The principle of the heater-hot cathode for use in AC operated radio receivers was first developed in McCullough tubes in the 1920s, for the elimination of hum from AC filaments in radio frequency and detector tubes. The heater, insulated from the cathode, raised its temperature to the point were electrons were emitted as in the case of a regular filament, and when connected as a conventional filament, this cathode functioned similarly and without hum."
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.324397
label: catalog number
content: 324397
label: accession number
content: 252994
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 5/8 in; 10.16 cm x 4.1275 cm