Atlantic Pacific solenoid tube
date: label: date made
content: 1922
name: label: maker
content: Atlantic Pacific Radio Supplies Company
notes: label: Description (Brief)
content: An electron relay having a brass base with 4 pins, and a tipped T-shaped envelope. Stamped: "1108". Donor's card reads: "Triode made by the Atlantic Pacific Radio Supplies Company, 638 Mission Street, San Francisco. A most unusual design, presumably made in the fall of 1922 or shortly thereafter to circumvent the triode tube patents. Technically it is a triode, with a grid wound as a two-layer coil around the filament and the plate mounted on the end (top) of the glass grid spool. The two layers of grid windings are separated by a layer of mica in a differential relation so that no consequential magnetic field results from the grid coil, or "solenoid." Circuit diagrams supplied with the tube indicate that the four pins of the Shaw base are conventionally connected as to plate, grid, and filament; however, a fifth connection, to the brass shell of the base, brings the remaining end of the grid coil (solenoid) outside for connection into the circuits of the receiver in which the tube is used.
label: Description (Brief)
content: Careful check of the two circuits shown in the circular shipped with the tube, while somewhat different in appearance at first glance, are actually conventional regenerative or plate feed-back circuits with very slight modifications to use the fifth tube contact as a double connection to a single grid. Due to the differential winding of the solenoid coil, there is no magnetic field of consequence nor inductive value in connection with the radio frequency circuits involved."
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
creditLine: label: Credit Line
content: from Paul G. Watson
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.324332
label: catalog number
content: 324332
label: accession number
content: 252994
objectType: label: Object Name
content: Electron Tube, Triode
label: Object Name
content: triode
label: Other Terms
content: Electron Tube, Triode; Electron Tubes
physicalDescription: label: Measurements
content: overall: 4 in x 1 3/4 in; 10.16 cm x 4.445 cm