29 Aug
2008
29 Aug
'08
11:59 a.m.
On 29 Aug 2008 at 14:13, William Donzelli wrote:
Well, OK, i could buy that, but from what I have seen
from the
circuits and construction of tube logic circuits is that the 3 pF is
not much compared to all the stray capacitance kicking around due to
construction techniques.
In particular, the tube socket. Not as bad as the phenolic based
tubes, but still a factor. In early HF work, you'd see tubes with
the base removed or with hacksaw slots in the base between pins--and
connections soldered directly to the pins.
Your comment about space-charge tubes brings up the question "Did any
AM/FM auto radios used them?" An FM application might indicate some
speed potential.
Cheers,
Chuck