Anybody have a copy of the Application Note for the 6GH8? RCA promoted the 6GH8 to everybody, and the application note (24 pages, according to my Radiotron Designers Manual) probably had a sampling of RCA-designed circuits for use with the 6GH8's - Audio, Video, Chroma, Pulse, you name it. It's the broad application (and RCA's insistance that it be used in every RCA TV) that brought it into the limelight. 6EA8, 6U8, 6BL8, 6KT8 - everybody used some form of the triode-pentode in their sets.
When I was a kid in my Dad's TV shop., I would be amazed when he would fix a set with a 6GH8 problem,
by merely swapping the 6GH8 out with another 6GH8 in the set, never having to replace anything. Not working as a Chroma Oscillator? No problem - swap it with the Bandpass Amp tube (another 6GH8) and watch the magic. You could throw a hundred 6GH8's in a circuit and find that only half would work, but all would test fine on any Hickok, Sencore or B&K tube tester out there. I'm sure it boils down to different electrical characteristics that are never tested - stuff like plate capcitance, inter-electrode capacitance, and the like.
It would be interesting to contrast the 6GH8 with "the most used transistor of 19
80 - would it be a 2SC1172B, a 2SC945, or some other Japanese wunderkind?
Cheers,