> I don't normally run this amp that hard, some do. I don't think this
> amp has any parasitics, but I have not tried this amp yet on the
> higher bands, 15,20.
What you all seem to miss is it is physically impossible for a parasitic to
cause a G-K short in a tube by bending the filament, so why would an
oscillation (even if it occurred) be an issue???
The peak AC operating current puts more bending force on the filament than
any emission related force ever would. The filament's normal peak current
operating is 21 amperes. The peak saturated emission current avail;able in
any oscillation would be much less than half that value!
To put this into perspective, look at the hairsprings and power of a magnet
in a panel meter. Look at the small amount of torque produced.
If we look at the size of the anode choke wiring in the amplifier, where ALL
plate current must pass, and see nothing moves that alone should clear up
this rumor that was started and kept up by one person from California. If
dozens of turns of very fine wire in the choke doesn't collapse, why would a
much stronger and thicker small diameter helice bend and displace?
The ONLY reason chokes have enough energy to displace wire is through a HV
flashover or arc in a tube, never from emission limited currents like an
oscillation would produce.
The parasitic paranoia is very odd. I'm having a tough time understanding
why so many otherwise reasonable people swallow it! I understand why a guy
selling kits would blame every failure on a parasitic, it is good for
business. But I really don't understand why so many people don't reason
through the problem.
Or is it desperation?
73 Tom
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