[Amps] VHF Parasitics re-revisited

[Bill Turner]

ORIGINAL MESSAGE:

At 12:00 AM 5/4/2006, Steve Thompson wrote:

>Being pedantic, it doesn't require any tuned circuits at all. The
>condition is gain>1 and phase=0. How you avoid this doesn't matter. How
>it arises can vary wildly, with very different optimum cures. What goes
>on with circulating currents and stray fields outside the tube can be
>more significant than internal feedback. A resonance gives you rapid
>phase changes over a narrow frequency, which increases the likelyhood of
>getting the right phase for oscillation, but it's not a prerequisite.
> >

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Well, that's an interesting observation. Is it possible to have a 
triode g-g oscillate without at least a rudimentary resonant circuit 
in both the anode and grid circuit?

I'm sure some resonant circuits in the grid circuit are not 
immediately apparent to the casual observer, but is it possible for a 
g-g tube to oscillate without one?

Bill, W6WRT