>> 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???
According to some, arc-welding cables can't move when striking an arc
unless aided and abetted by voodoo. I guess we got some o' that voodoo
stuff down right here in Somis' down at the welding shop,
>
>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!
>
The fusing current of #28 Cu is >15A.
>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.
An arc which does not leave an arc mark, that occurs in a tube with a
good vacuum. So maybe the Fairy Godmother dropped by and sucked out the
gas with her magic twanger wand?
>
>The parasitic paranoia is very odd. I'm having a tough time understanding
>why so many otherwise reasonable people swallow it!
Good question. Maybe these folks do not believe that the Q of
resistance-wire inductors increases with frequency? Or maybe some people
are not quite convinced that AC circuit-analysis really and truly doesn't
apply to VHF-suppressors? It's also possible that some of 'em have
actually been in a welding shop.
>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?
"Look Ma, Everybody's out step except our Johnnie". -- Bill Mauldin
>
have phun, Tom
thanks
- R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K,
www.vcnet.com/measures.
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