Lowell & Dunmore demonstration A.C. radio receiver
date: label: date made
content: 1924
label: associated date
content: 1929
name: label: associated user
content: unknown
label: associated person
content: Dunmore, Francis W.
label: associated institution
content: Bureau of Standards
label: associated person
content: Lowell, Percival D.
label: maker
content: National Bureau of Standards
label: maker
content: C. Brandes Inc.
notes: label: Description (Brief)
content: Marked: (1) Plaintiffs Exhibit No. 48. U.S. Pat. Office. Interference Nos. 51204-51702-53153-53154-53155. Lowell & Dunmore Exhibit No. 34. (2) Supreme Court of the U.S. Oct. Term, 1935. Plaintiffs-Respondents Exhibit No. 26 (for detailed data see Acc. Papers) Unit employs four 215A "peanut" tubes and three 201A type triodes. Circuit appears to be of the tuned radio frequency (TRF) type with three point rotary switches on RF coils. Two RF stages are followed by a detector and three audio stages, with one 215A tube as the first audio and a 201A tube in the second and third audio stages respectively. Transformer coupling is employed in the audio section. A power transformer is mounted in the box frame with a Federal 132W filter capacitor, a filter choke, and a 201A tube used as a rectifier. A Brandes "Table-talker" loudspeaker is mounted in the case. This receiver was demonstrated by patent attorney J.B. Bradly to Dubilier corporation engineers in 1924. Dubilier entered into a license agreement with P.D. Lowell & F. W. Dunmore, co-inventors of the battery-less receiver under U.S. Pat. 1455141. Reference: 4th Circuit Ct. of Appeals, Transcript Vol. I. pages 16-17, Vol II, page 253 (photograph).
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.321935
label: catalog number
content: 321935
label: accession number
content: 245709
objectType: label: Object Name
content: Receiver
label: Object Name
content: radio receiver
label: Other Terms
content: Receiver; Radio
physicalDescription: label: Measurements
content: overall: 13 1/2 in x 22 1/8 in x 12 1/4 in; 34.29 cm x 56.1975 cm x 31.115 cm