Summary

Directly heated triode designed to give satisfactory performance as an amplifier with its filament operated on an AC supply; the same as the RCA UX226.

The low voltage high current (1.5 V, 1.05 A) filament was designed to minimize temperature fluctuations during the AC cycle and produce a magnetic field that would compensate for the alternating electric field produced by the AC supply.
These valves were used in the RF and audio stages of early AC radios. An indirectly heated valve (227) had to be used as the detector but it cost about twice as much as the 226 so it was only used where it was essential. Once the cost of indirectly heated valves fell, the 226 became obsolete. It was renamed 26 and continued to be made for replacement use in the early 1930s.

1.5 V directly heated cathode.

Manufactured by RCA, Harrison, NJ, U.S.A.
Manufactured for E.T. Cunningham, Inc.

Physical Description

Conical glass bulb on four pin UX style base.

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