>[Dick Ehrhorn:] Jon, I think it'd be much more accurate to say that
>(virtually?) all circuits contain parasitic reactances and therefore
>parasitic resonances, which lead to the potential for parasitic
>oscillations when used with many or most types of tubes.
You are absolutely correct. Most of the time on HF, they are not a
problem. However, even at VHF lead inductances and other circuits will
KILL a circuit. I remember trying to build my fist VHF amp as part of my
senior project in college. People told me to use mica caps. So I put
some on a vector impedance meter and was I ever surprised - they looked
like inductors at 144 MHz! I ended up using chip caps instead.
Anyhow Dick, you are correct. But I was specifically talking about HF
tubes here which is why I didn't say all circuits.
73,
Jon
KE9NA
-------------------------------------
Jon Ogden
KE9NA
http://www.qsl.net/ke9na
"A life lived in fear is a life half lived."
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