> >Something puzzles me here. If the suppressor provided the whole plate
> >load impedance at the parasitic frequency, then the gain would be
> >reduced by
> only
> >4.3dB by lowering the parallel resistance from 160 to 101 ohms. This
> >may be enough to just stop the parasitic, but doesn't appear to my
> >mind to give
> enough
> >margin to ensure stability.
>
>
> Is it quite that simple? The suppressor is part of a *series* circuit
> from the anode through the blocking cap, connecting wires and tune cap
> so Rs is the number that counts. In a typical layout, the connecting
> leads swamp the Ls (and therefore Lp) of the suppressor.
>
> Steve
That's right Steve, neither Rich nor Peter are looking at the problem
correctly.
The effect of the rest of the system is such that LOWER Rp
increases system Q.
It does not guarantee a reduction in gain at all.
The lowest Rp suppressor is no suppressor at all and zero Xp. The
best suppressor has the highest Rp and infinite Xp.
Measures suppressor, if it has lower Rp, is actually closer to NOT
having a suppressor at all! It will INCREASE VHF Q over a higher
Rp suppressor.
>
> --
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>
73, Tom W8JI
W8JI@contesting.com
--
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