>
>> Ä One of the debators tested the 922's cooling ability, and one debator
>> probably only pontificated about it. // The Grate Parasitic Debate is no
>> longer controversial. The missing piece of the parasitic puzzle was how
>> does the VHF potential from the anode get stepped up to roughly double the
>> anode supply voltage, thereby resulting in bandswitch and/or Tune-C
>> arcing?. The answer is that when there is a VHF series-resonance in the
>> Tune-C at a frequency Near the parasite, the Tune-C acts as a Z-step-up
>> L-network instead of a low-Z path to gnd. The person who made this
>> important discovery is Mr. Rauch. Congrats, Tom. Unfortunately, he is
>> seeming too embarrassed to discuss it with any of us in public.
>
>Rich, you are amazing!
>
>The series resonance actually makes the input impedance of the
>tank look like only a few ohms!
>
This is true only when the series resonance is not offset from the
parasitic freq. L-networks are never resonant. When the resonance is
Near but not dead-on the parasitic freq., the L-network effect comes into
play and the potential is substantially increased.
>It actually makes it impossible for the tube to drive significant
>voltage at the tank at VHF!
>
? You seem to have missed the word "Near", Tom.
>Thanks goodness for that, because if the tuning capacitor did allow
>significant VHF or UHF voltage the amp would be a TVI nightmare.
>
? Which TV station is on 120MHz?
>Nice try though! A for effort!
>
? "A" for Avoidance of reality.
>
later, Tom.
- Rich..., 805.386.3734, www.vcnet.com/measures.
end
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