William Donzelli wrote:
I have exactly one 12U7 in stock. I have a few 12K5s,
as
well.
I've now got a number of different dual triode tubes to try from a local electronics
shop that has a large collection of tubes from former TV and radio repairmen. $1 each and
they have a B&K 707 tube tester to test them on.
One thought about using space charge tubes for logic -
they
might end up being slow as molasses.
From a message above, it looks like even a 6.3V plate
voltage on a standard (not low voltage) dual triode tube will work and I'm after a
visibly slow (a few Hz at most) multivibrator anyway with a binary counter circuit
attached.