Summary

This valve contains two identical independent medium mu triode units in the one bulb. Mainly used for audio amplification (Class A amplifier). The base notice about replacement use only suggests production during World War II (1939-1945).
Manufacturer: Raytheon Manufacturing Co., Newton, Massachusetts, USA.
6.3 V indirectly heated cathode.

Physical Description

Small shouldered bulb (with top cap) on 8 pin octal style base.

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