Summary
General purpose triode.
The McCullough type 401 was the first indirectly heated valve to be marketed in the USA. It was introduced in 1925. The heater connections are via the two pins in the top of the bulb. They were designed so that they could be used to replace the directly heated valves in a radio, allowing AC operation. They were used by a small number of radio manufacturers as original equipment. For example Sparton used them for their 1927 AC models.
Manufacturer: Kellogg Switchboard and Supply Company, Chicago or A.C. Neon Corporation, New York City.
3 V indirectly heated cathode. Used as a Class A amplifier.
Physical Description
Conical bulb with 4 pin UX style base with two side pin top contacts for heater.
More Information
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Collection Names
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Collecting Areas
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Acquisition Information
Donation from Wireless Institute of Australia, Mr Max Howden, 28 Apr 1967
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Manufacturer
Kellogg Switchboard and Supply Company, Chicago, Illinois, United States of America, circa 1928
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Manufacturer (Possible)
A.C. Neon Corporation, New York City, New York State, United States of America, circa 1928
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Inscriptions
Base: McCullough/Type 401/A-C Tube
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Brand Names
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Classification
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Category
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Discipline
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Type of item
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Overall Dimensions
134 mm (Length), 41 mm (Outside Diameter)
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References
[Book] Tyne, Gerald F. 1987. Saga of the Vacuum Tube., 1987, 344-345 Pages
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Keywords