Sensibly equivalent¶ to:
The 7C6 is a double diode triode, and no specific design use is quoted. Normally such a valve would be used as signal and AGC detector plus first audio amplifier stage in broadcast receivers. This valve is unusual in that the anode impedance is high, maybe this valve was to be used for video demodulation and amplification.
The design dates to the late 1930's in America and the UK versions are post-war.
The gettering on the inside of the glass prevents inspection of the internal structure. See 7C6 for an example with a partly clear envelope.
The wide glass tube envelope is 28 mm in diameter and, excluding the B8B base pins, is 57 mm tall.
References: Datasheet, 1040 & 3002. Type 7C6 was first introduced in 1938.
Absolute Maximum Operating Conditions¶
Updated March 05, 2018. shape:wide.glass.tube construction:all.glass type:triode age:1930.1940 base:b8b heater:6.3v pins:8 pin:1.h pin:2.a pin:3.g1 pin:4.k pin:5.a(d2) pin:6.a(d1) pin:7.k pin:8.h