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[AMPS] Feedback path 3-500Z

To: <amps@contesting.com>
Subject: [AMPS] Feedback path 3-500Z
From: 2@vc.net (measures)
Date: Fri, 29 Sep 2000 11:43:40 -0700
>
>> Several uF HV cap filter is in parallel with 1000 pf Bypass, reactance is
>> several uF//1000pf, a like a short (-j0) on VLF. The 8 uH inductor is in
>> series with the previous found load, 8 uH is about j10 Ohm at 200 Khz. But
>> +j10 Ohm is in parallel with the second 1000 pF (-j796 Ohm @ 200 Khz), and
>> equivalent impedance is about j9.7 Ohm. The 50 uH inductor is in series,
>> Xl is +j62.8 Ohm at 200 Khz, and in series with +j10 Ohm the equivalent is
>>  +j72.4 Ohm. Until now, on plate is applyed a +j72.4 Ohm reactive load,
>> value thatís already a full safety against feedbeck for VLF oscillations
>> unless an opposite -j72.4 reactance would resonate it. Of course there is
>> a blocking capacitor in series from plate to PI and its reactance at 200
>> KHz is around -j800 Ohm. Then, what is after (in series) with blocking cap
>> must be +j872.6 to resonate plate at 200 KHz.
>> 
>> In other words, better to say in numbers, we need that PI and antenna load
>> looks like a 694.7 uH equivalent inductor to resonate plate at 200 KHz.
>
>The 1000 pF blocking capacitor can easily look like j800 or any 
>other value depending on the load at the output of the pi-net.
>
>Do you agree or disagree with that?
>
>I can look at the anode with an impedance measuring set and 
>move the frequency of peak anode impedance anywhere I like in LF 
>and VLF, because the pi-net is transparent at those frequencies.
>
>Grounding the grid solves all this nonsense.

?  No one that I know has seen Mr Rauch's alleged 205KHz oscillation in a 
SB-220.  At least two people have seen the 220's normal damped wave 
ringing at 110MHz on a spectrum analyzer.  

on and on and on

end

-  Rich..., 805.386.3734, www.vcnet.com/measures.  
end


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