Sensibly equivalent¶ to:
The 12BA6 is a variable μ pentode for use at HF within AC/DC receivers. Most probably as RF amplifiers. This exhibit from Pinnacle also carries the Type designation of HF93.
The original maker's identification is etched into the glass. Pinnacle have added the printed wording.
The thin glass tube envelope is 18 mm in diameter and excluding the B7G base pins, is 46 mm long.
References: Datasheet & 1040. Type 12BA6 was first introduced in 1946.
Absolute Maximum Operating Conditions¶
Updated November 09, 2018. shape:thin.glass.tube construction:all.glass type:pentode age:1940.1950 base:b7g heater:6.3v pins:7 pin:1.g1 pin:2.g3.s pin:3.h pin:4.h pin:5.a pin:6.g2 pin:7.k