31 Aug
2006
31 Aug
'06
12:32 p.m.
Stan Barr wrote:
Just for informational purposes: 12AU7s (and 12AX7 and 12AT7) are still
available new. You probably won't like the price, but they're still in
production - us electric guitar players use them,
Note that for flip-flops one should 'properly' be using types such as 5963 or
6211 ("computer tubes") to avoid the cathode emission problems which results
from one half of the flip-flop being in the same state
for long periods (IIRC
it was the one at cut-off). (Perhaps not a problem for a
clock, I don't how
extreme the asymmetry had to be before the problem showed up.)