Rich Measures wrote:
>
> .....
> >Does any one know the reason why Heath would chose to float the grids
> >above
> >ground on the 500z tubes. they are bypassed for rf thru a couple of chokes
> >and capacitors, it seems to me it would make more sence to ground them
> >directley to the chassis, for better isolation and stability.
> I have tried direct-grounding the grids and grounding the grids through
> 3, 200pF capacitors. The grid's self resonant frequency is not
> significantly different either way. Amplifiers that use
> directly-grounded grids seem to oscillate occasionally at VHF, as do
> amplifiers that use the C-bypassed grid approach. If you want to improve
> VHF stability, you might try decreasing the VHF-Rp of the parasitic
> suppressors.
> cheers, Dick
> Rich---
>
> R. L. Measures, 805-386-3734, AG6K
>
Well, Mr. Measures,
I knew I could count on you to have the answer.
Hum-so-ever, your tardiness cost me a bet.
I was betting you would be the first to reply, and I regret to tell
you that your reply was the second one I received.
Second in time, but first in quantity of information provided.
Tnx es 73,
Dan
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