-----Original Message-----
From: Peter Chadwick <Peter_Chadwick@mitel.com>
To: Jon Ogden <na9d@mindspring.com>; 'measures' <2@vc.net>
Cc: amps <amps@contesting.com>
To: <amps@contesting.com>
Date: 23 March 2001 09:12
Subject: RE: [AMPS] SB-220 Amplifiers and Garage Sales!!
>
>Rich says:
>
>> Rp was 101-ohms for a resistance-wire suppresor vs. 166-ohms for a
>>copper-wire suppressor.
>
>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
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