Kolster arc radio transmitter from Lowell & Dunmore case
date: label: date made
content: ca 1919
label: date made
content: c 1919
name: label: associated institution
content: Bureau of Standards
label: maker
content: National Bureau of Standards
notes: label: Description (Brief)
content: A component from the Lowell & Dunmore patent case Bureau of Standards R-2711. Marked: Tags: Pat. Office Interferences Nos. 51204-51702-53153-53154-53155. Lowell & Dunmore Exhibit no. 55. Designed by Dr. Kolster of the Bureau of Standards. Unit has two electromagnet choke coils, an arc chamber with adjusting handle, and a motor with gear wheel, all mounted on a wooden base. The choke coils were used by P. D. Lowell and F. W. Dunmore in the filtering section of a "Tungar" rectifier circuit associated with the original alternating current receiver; (NMAH number EM.321925). This circuit supplied 110 volts direct current to the field coil of a Magnavox speaker unit. Reference: U.S. Patent Office: "Record and Testimony on Behalf of Lowell & Dunmore", pages 553-554.
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
creditLine: label: Credit Line
content: from John B. Brady, thru Mrs. John B. Brady
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.321936
label: accession number
content: 245709
label: catalog number
content: 321936
label: collector/donor number
content: R2711
objectType: label: Object Name
content: radio transmitter
label: Other Terms
content: Radio
physicalDescription: label: Measurements
content: overall: 16 1/4 in x 12 in x 12 3/4 in; 41.275 cm x 30.48 cm x 32.385 cm