Summary
General purpose triode with a filament in two halves in series with the centre tap connected to the base shell. Released in 1922. 5 or 2.5 volt directly heated cathode.
Manufacturer: Moorhead Laboratories, San Francisco, CA., USA.
Physical Description
Cylindrical bulb with top exhaust tip on 4 pin UV style base (metal shell and ceramic insert), mounted on display blockwith ST 15935.
More Information
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Collection Names
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Collecting Areas
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Acquisition Information
Donation from P. H. McElroy, 22 Jul 1926
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Manufacturer
Moorhead Laboratories, San Francisco, California, United States of America, circa 1922
See Inscription. A.P. Radio Laboratories had the same address as Pacific Radio Supplies Co., the distribution arm of Otis B. Moorhead's operation in San Francisco. -
Inscriptions
Base: "TWO in ONE"A.P.Tube/MADE BY/A.P.RADIO LABORATORIES/SAN FRANCISCO/PATENTS PENDING/6Volt.25A Display block: (text)
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Brand Names
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Classification
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Type of item
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Overall Dimensions
107 mm (Height), 44 mm (Outside Diameter)
Dimensions of valve, excluding display block.
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References
[Book] Stokes, John. 1982. 70 Years of Radio Tubes and Valves., 1982, 74 Pages
[Book] Tyne, Gerald F. 1987. Saga of the Vacuum Tube., 1987, 177 Pages
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