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Re: [Amps] plate choke

To: "R.Measures" <r@somis.org>
Subject: Re: [Amps] plate choke
From: KD7QAE <KD7QAE@ARRL.NET>
Date: Thu, 25 Aug 2005 14:44:46 +0100
List-post: <mailto:amps@contesting.com>
So, Are you telling me that at every operating frequency of the amp I 
have to design the plate choke so that it has a parallel resonance?  
That is impossible without adding some sort of tuning mechanism, which 
clearly isn't done in practice.  You cannot count on parallel resonance 
for the general wide band plate choke design.  I agree w/ Rich's analysis.

Tomm, KD7QAE

R.Measures wrote:

>On Aug 25, 2005, at 4:52 AM, Roy Koeppe wrote:
>
>  
>
>>If...
>>
>>"Reactance at 1.8MHz = 3099 Ohms"
>>
>>Then,
>>
>>With 3 kv on the plates, circulating current through the choke winding
>>and through the by pass cap is 1 amp?
>>    
>>
>
>With a 3kV anode supply, The peak change in anode potential is c. 
>2700v-pk   0.707 x 2700v = c. 1900V-rms, so the circulating current 
>through the HV-RFC is 1900v / 3099-ohms = 0.616A-rms
>  
>
>>You see, this is a useless parameter.
>>    
>>
>
>Not quite since the HV bypass C must be able to carry 0.616A at 1.8MHz 
>without overheating and igniting.
>
>  
>
>>Circulating current is limited by
>>parallel resonances in the winding,
>>    
>>
>
>At 1.8MHz, with a typical Ham amplifier - I don't think so.
>
>  
>
>>which present a much higher
>>effective resistance to the tank circuit.
>>
>>73,    Roy     K6XK
>>
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>>
>>
>>    
>>
>
>Richard L. Measures, AG6K, 805.386.3734.  www.somis.org
>
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>
>
>  
>


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