[AMPS] Blown TL922A... What to do?

[Tom Rauch]

> €  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!

It actually makes it impossible for the tube to drive significant 
voltage at the tank at VHF! 

Thanks goodness for that, because if the tuning capacitor did allow 
significant VHF or UHF voltage the amp would be a TVI nightmare.

Nice try though! A for effort!


73, Tom W8JI
w8ji@contesting.com

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