Magnavox type R-3 model B "Telemegafone" loudspeaker
date: label: date made
content: ca 1921
name: label: maker
content: Magnavox Company
notes: label: Description (Brief)
content: Marked: "Radio Magnavox / Patented Made in USA / Type R-3 Mod. B. No. 61879 / The Magnavox Co. / Oakland, California". Patent dates: 1/21/13: 2/3/20; 2/24/14; 3/2/20; 8/4/14; 10/20/20; 5/21/18." Horizontal coil with cover, 2 binding posts on either end for external circuit connections (4 posts total). Unit with attached speaker horn is an early example of an electro-acoustical reproducer for receiver audio stages. Complete Telemegafone consists of an enlarged version of the electrodynamic receiver equipped with a large horn, a step down transformer, binding posts for the signal current and the magnet energizing current, and a sound tube headset for reading faint signals. Magnavox equipment of this type was used in Washington, D.C. at the opening of the Victory Loan Drive when an Air Service officer in a radio equipped plane 3000 feet overhead read President Wilson's cablegram message to an outdoor audience of 30,000. Reference: QST, May 1920, pages 20-21. Undated "Telmaco Catalog", p. 47.
label: Location
content: Currently not on view
place: label: place made
content: United States: California, Oakland
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.321203
label: accession number
content: 241556
label: catalog number
content: 321203
label: model number
content: B
objectType: label: Object Name
content: telemegafone
label: Object Name
content: loudspeaker
physicalDescription: label: Measurements
content: speaker only: 5 3/4 in x 5 1/2 in x 8 1/4 in; 14.605 cm x 13.97 cm x 20.955 cm
label: Measurements
content: horn: 22 in x 14 in; 55.88 cm x 35.56 cm