Sensibly equivalent¶ to:
The 12BH7 double triode is pin compatible with the ECC81,2,3 series from Mullard but has slightly different characteristics. Brimar give an intended use as a TV frame valve for wide deflection angle tubes, but the construction is compatible with audio through to low VHF use.
The Brimar 12BH7 was listed in the Brimar manual of 1953 but not earlier.
The thin glass tube envelope is 20 mm in diameter and excluding the B9A base pins the length is 57 mm.
References: Data-sheet & 1040. Type 12BH7 was first introduced in 1950.
Absolute Maximum Operating Conditions¶
Updated February 21, 2013. shape:thin.glass.tube construction:all.glass type:double.triode age:1950.1960 base:b9a heater:6.3v pins:9 pin:1.a pin:2.g1 pin:3.k pin:4.h pin:5.h pin:6.a pin:7.g1 pin:8.k pin:9.hct