While rummaging through my tube storage I came across some boxes of Compactron tubes which I never used. So I decided to take a closer look and present them. Starting with the 6BH11.
The 6BH11 makes use of all the 12 available pins of the Compactron base and contains 2 triode systems for general purpose use and a pentode which was designed for use as horizontal deflection oscillator in TV sets.General Electric datasheet for all technical details. Most of such Compactron tubes are largely ignored nowadays although many of them could be used in audio or guitar applications. They can be picked up for mere pennies. As always let's have a look at the plate curves, starting with the curves of the triode sections as shown in the datasheet:
Not exactly as linear as other triodes but for low level applications that would not be critical. Here the curves of an actual tube:
A few close ups:
Some views from the side:
Ok let's open one up to see more details of the construction.
One of the triode sections:
Quite an intersecting tube and advanced construction details which is typical for such tubes which were manufactured in the 1960ies.