[Milsurplus] TCS Crystal oscillator tube sub

[Kenneth G. Gordon]

Crapola! :-(

I made a big mistake!

Scratch the 6K6 or 6F6: the suppressor is connected internally to the 
cathode, which will NOT work in this circuit since the cathode is part of the 
feed-back circuitry. The suppressor would bypass the shielding of the 
screen. Wouldn't work much better than a beam tube.

At this point, I would use a pair of 6AG7s, 6AK7s, 6CL6s, or 12BY7s, socket 
adapters, and balancing resistors in the oscillator and buffer sockets.

Or a single one of the above, a socket adapter, and balancing resistors.

Or as Hue suggested a 12SK7, 12SG7, or 12SH7 and a socket adapter.

The last two might make a better oscillator as they show higher 
transconductances.

None of the last three above would need balancing resistors since their 
filament requirements are identical to the 12A6.

Might have to play with biasing of the buffer to get a bit more drive, though.

Looks like Hue's suggestion is far better than mine.

Gee...

Ken W7EKB