Bureau of Standards type B radio receiving relay
date: label: date made
content: ca 1922
label: associated date
content: 1922
name: label: associated person
content: Lowell, Percival D.
label: associated institution
content: Bureau of Standards
label: associated person
content: Dunmore, Francis W.
notes: label: Description (Brief)
content: Marked: "(1) Patent Office Interferences Lowell & Dunmore Exhibit No. 47. (2) US of America vs. Dubilier Condenser Corp. -- Plaintiffs Exhibit No. 68 (3) Supreme Court of U.S., Oct. Term, 1935 Plaintiffs--Respondents Exhibit No. 23 (for detailed date, see Acc. Papers) Title on front panel." Unit, developed at the Bureau of Standards by P.D. Lowell & F.W. Dunmore, is a relay recorder designed to operate from the output terminals of a radio receiver or other source of audio frequency signal. Unit is designed to work a sounder, buzzer, tape register or any mechanism for remote control by radio. Type A Relay was operated by battery power supply, and Type B from 60 cycle, 110 volt A.C. In this specimen, two receiving tubes are used as rectifiers, with grid and plate tied together in each tube. A fan switch on the panel is connected so as to arrange various capacitances across the secondary of the audio-frequency transformer, reducing 60 cycle hum. The relay on specimen was activated by two 201A type triodes with plates and grids of each tube tied together. Plate currents of 1-10 milliamperes normally were used. Unit is contained within a wooden box with a composition panel. filament rheostats, telephone tip jacks and various binding posts are arranged on the panel. Three 201A tubes are in sockets, one missing. Reference: U.S. Pat. Office: "Record and Testimony on Behalf of Lowell and Dunmore", pp. 551-553 91928). Third Circuit court of appeals Transcript Vol. II (1931) pages 362-367; pp. 388, 388-1; pp. 405-409.
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.321927
label: catalog number
content: 321927
label: accession number
content: 245709
objectType: label: Object Name
content: Relay, Receiving
label: Object Name
content: radio relay
label: Other Terms
content: Relay, Receiving; Radio
physicalDescription: label: Measurements
content: overall: 10 1/2 in x 11 in x 6 3/4 in; 26.67 cm x 27.94 cm x 17.145 cm