Summary

Tetrode, made by Radio Corporation of America, branded Cunningham Radiotron, introduced in early 1930s. It was used in radios as a radio or intermediate frequency amplifier. It was designed specifically for car radios.

This is an early example of a valve with a 6.3 Volt heater, a voltage, which would allow operation from a 6 Volt car electrical system.

It had a 6.3 volt indirectly heated cathode and used as class A r.f. amplifier.

Physical Description

Five pin base with top cap.

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