Knight B-battery eliminator
date: label: date made
content: c 1925
label: date made
content: ca 1925
name: label: maker
content: Knight and Company
notes: label: Description (Brief)
content: Marked: "Knight / 'B' Battery Eliminator / 110-120 Volts AC 60 cycle current". Unit is a "B" battery eliminator, designed to apply rectified plate voltage to radio tubes of the mid 1920s. A true built-in AC power supply for radio receivers was not in general commercial production until 1927. Unit has a rectifier tube (missing) and transformer with associated filter choke. Detector and amplifier tube voltages are made variable by two external controls.
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
creditLine: label: Credit Line
content: from Franklin Wingard
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.321411
label: catalog number
content: 321411
label: accession number
content: 241556
objectType: label: Object Name
content: power supply
physicalDescription: label: Measurements
content: overall: 9 in x 12 1/2 in x 4 3/4 in; 22.86 cm x 31.75 cm x 12.065 cm