French type R-4 radio frequency amplifier
date: label: date made
content: c 1922
label: date made
content: 1919
label: associated date
content: 1921
name: label: associated institution
content: Bureau of Standards
label: maker
content: Chauvin & Arnoux
notes: label: Description (Brief)
content: Lowell & Dunmore. Nameplate on side: "Amplificateur Haute Frequence / Modele de la Telegraphie Militaire / Type R 4 No.5"; on milliameter: “Chauvin & Arnoux Paris No. 2512"; on front: "R2604", Tag: "In the U.S. Pat. Off. Interferences Nos. 51204-51702-53153-53154-53155. Lowell & Dunmore Exhibit no. 59". Unit is a four tube resistance coupled amplifier. Tubes are missing. Back pane of unit is broken. A 0-1 milliameter is mounted on the front panel. A heavy transformer is mounted internally. Circuitry appears to be three stages of radio frequency amplification and a single tube detector. Unit was used with French multiple tuner (Cat# 321934) in experiments relative to the radio recording relay. In Fall 1921 the French tuner and amplifier were employed with a radio relay to receive signals from station P02 at Nouen, near Berlin. These experiments related to the resistance coupled radio frequency amplifier were conducted by P.D. Lowell and F.W. Dunmore of the Bureau of Standards. Ref: In the U.S. Pat. Office: "Record and Testimony on Behalf of Lowell & Dunmore", pages 44-45, 548-549.
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.321938
label: patent number
content: 1455141
label: catalog number
content: 321938
label: accession number
content: 245709
label: accession number
content: 245709
label: collector/donor number
content: R2604
objectType: label: Object Name
content: Receiver
label: Object Name
content: delete
label: Object Name
content: radio receiver
label: Other Terms
content: Receiver; Radio
physicalDescription: label: Measurements
content: overall: 10 3/4 in x 13 1/2 in x 9 1/2 in; 27.305 cm x 34.29 cm x 24.13 cm