Sensibly equivalent¶ to:
RCA introduced the glass foot with metal envelope can in 1935 and the double diode 6H6 is the smallest envelope used. The construction is of a pressed glass foot holding the electrodes and sealed into the steel envelope. The lead-out wires were then attached to the octal base, also introduced in America in 1935. In subsequent years the glass foot was used to hold hard metal pins and the all glass valve was born.
This Marconi 6H6 was made in Canada probably by RVC.
The glass enveloped 6H6 valves used pinch construction and were much larger physically.
The reverse is just plain black paint.
The thin metal tube envelope is 25 mm in diameter and, excluding the IO base pins, is 29 mm tall.
References: Datasheet & 1040. Type 6H6 was first introduced in 1935.
Absolute Maximum Operating Conditions¶
Updated December19, 2016. shape:thin.metal.tube construction:glass.disc type:double.diode age:1940.1950 base:io heater:6.3v pins:8 pin:1.m pin:2.h pin:3.a(2) pin:4.k(2) pin:5.a(1) pin:6.- pin:7.h pin:8.k(1)