Lowell and Dunmore original Bureau of Standards AC-powered radio receiver

Lowell and Dunmore original Bureau of Standards AC-powered radio receiver

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Usage conditions apply
Description (Brief)
Unit is a 6 tube tuned radio frequency receiver designed to operate from a separate power supply. (Cat.#321,926). Specimen developed at Bureau of Standards in 1922 by P.D. Lowell and F. W. Dunmore as a very early application of the alternating current power supply to a radio receiver. The circuitry consists of three RF stages, a crystal detector and two audio stages. The crystal was used to help reduce the problem of 60 cycle hum as well as being employed as the detector. Two adjustable balancing resistances were utilized for the purpose of reducing hum caused by grid voltage variations. For better simplification, a C battery was employed for bias in the final audio stages. Tubes used are 201A type. A speaker horn mounted under the lid is essentially a headphone unit driving a flare-type horn. This receiver was also connected to a Magnavox loud speaker unit. The RF stages employ Radio Instrument Co. DX transformers with a range of 170-450 meters. Depending upon the RF coils employed, this unit could recieve 30-1500 kc, AM or spark, and CW signals with the use of an external heterodyne.
Marked: (1) Supreme Court of the U.S., Oct. Term 1935 Plaintiffs respondents Exhibit No. 19. (2) United State of America vs. Dubllier Condenser Corp. Plaintiffs Exhibit No. 67. (3) Patent Office Interferences-Lowell & Dunmore Exhibit no. 45. (for detailed tag data see acc. papers) (Plate marked: BS31249) (Components lit-see Acc. papers). Reference: U.S. Dept. of Commerce Scientific Paper No. 450, Oct. 2,1922. U.S. Patent 1455141, Radio Receiving Apparatus, Issued May 15,1923 to P.D.Lowell & F.W. Dunmore. Vol 1- 4th Circuit Court of Appeals Transcript, pages 119-120.
Currently not on view
Object Name
radio receiver
Other Terms
Receiver; Radio; Table
date made
associated person
Dubilier, William
De Forest Radio Telephone & Telegraph Co.
Dubilier Condenser Corp.
Radio Instrument Co.
Magnavox Company
overall: 11 1/4 in x 15 in x 9 1/4 in; 28.575 cm x 38.1 cm x 23.495 cm
ID Number
catalog number
accession number
collector/donor number
Credit Line
from John B. Brady, thru Mrs. John B. Brady
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Work and Industry: Electricity
Data Source
National Museum of American History
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