General Radio model 107F variable inductance
date: label: date made
content: ca 1928
name: label: maker
content: General Radio Company
notes: label: Description (Brief)
content: Marked: "Variable Inductor / Type 107F Serial No. 1926 / General Radio Co. / Cambridge, Mass." Unit consists of two coils, both cylindrical sections mounted such that one rotates within the other. Two terminals are connected to each coil, so the coils may be used separately or connected in series or in parallel. Coils have a low resistance and are wound with stranded wire having a small variation of resistance with frequency. This specimen does not have the bakelite case, but consists of only of the panel and interior mechanism. The manufacturer supplied calibration curves accurate to 1% for an additional charge of $5.00. Inductance is variable from 0.02 to 0.4 mh and the coils can carry 3 amps continuously. Original price was $27.00. Reference: General Radio Catalog E, 1928, pages 37-38.
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.321795
label: accession number
content: 241556
label: catalog number
content: 321795
objectType: label: Object Name
content: variable inductance
physicalDescription: label: Measurements
content: overall: 5 7/8 in x 5 7/8 in x 8 in; 14.9225 cm x 14.9225 cm x 20.32 cm