-----Original Message-----
From: measures <2@vc.net>
To: Steve Thompson <rfamps@ic24.net>; AMPS <amps@contesting.com>
To: <amps@contesting.com>
Date: 05 August 2000 13:48
Subject: Re: [AMPS] Suppressors
snip
>>According to Wes' measurements, the suppressor contributes many 10s nH
into
>>the circuit.
>>
>The resistor has about 10nH. L-supp is in parallel with it. Total L
>can not be more than 10nH.
Where does the 50-100nH that Wes measured come from?
snip
>>That's not to say that the inductor value in the suppressor
>>isn't important - you have to choose R and L values to give the ESR vs
>>frequency characteristic that you need.
>>
>This is not the case. To optimize the staggered resonances effect, one
>needs equal VHF current in Rsupp and Lsupp.
>In other words -- An optimal suppressor divides the anode-resonance
>ringing current between L-supp and R-supp.
Why is it necessary to aim for this specific 'optimum' circumstance. There
are two requirements - one is to insert enough resistance to kill any VHF
resonance that might cause oscillation, the other is to insert sufficiently
little resistance at the operating frequencies. Any given collection of
components and layout will have its own particular optimum suppressor
values, and sometimes nichrome will achieve this better than copper.
The important point is the VHF Q of the whole anode circuit, and that is
controlled by the ESR of the suppressor, not the Q of the suppressor.
Steve
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