De Forest Type O Radiophone
date: label: date made
content: 1919
name: label: maker
content: De Forest Radio Telephone & Telegraph Co.
notes: label: Description (Brief)
content: Marked: 'De Forest / Radiophone / Type O Serial No. 190 / 60 cycle A.C. Supply / 7 US Pats. Pats. Pending / Not licensed for commercial work / De Forest Radio Tel & Tel. Co. / NY". Decal reads: "Distributed by Dubuque Radio Co., Dubuque, Iowa." Plate on panel reads: "To be used only for radio communication where messages are not transmitted for pay. Patd: 10-31-05; 2-18-08; 10-17-16; 3-6-17; 4-3-17; 7-29-19; 8-26-19; Other pats. pending. / De Forest Radio Tel. & Tel. Co. NY". Unit rests on a 14" X 15" oak base with a 14" X 20" bakelite panel. A carbon telephone transmitter is mounted on the panel with plate and filament current meters (latter missing). Filament rheostats are employed for rectifier and oscillator tubes. Rectifier tubes are mounted upside down. De Forest VT tubes are employed but are missing from unit. On the back of the panel are the tuning helix with adjustable clip, modulation transformer, tuning condensers, rheostats, filament switch, and condensers. A high voltage transformer is located on rear of baseboard. Original price with tubes: $260.00. Ref: Clark Collection: CL 15, F.D. Pitts Co. Catalog No. 22, page 75. Clark Collection: SRM 15-035, De Forest Catalog C, pages 49-51. Restored by R. LeRoche 9/63.
label: Location
content: Currently not on view
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.320809
label: accession number
content: 241556
label: catalog number
content: 320809
objectType: label: Object Name
content: Radio Transmitter
label: Other Terms
content: Radio Transmitter; Radio
physicalDescription: label: Measurements
content: overall: 20 in x 14 in x 21 in; 50.8 cm x 35.56 cm x 53.34 cm