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[AMPS] tuned inputs

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Subject: [AMPS] tuned inputs
From: (2)
Date: Tue, 10 Jul 2001 07:00:41 -0700
>on 7/10/01 12:03 AM, rick rosner at wrote:
>> ****  To  test  ur tuned  inputs put  a   100  ohm 1/4w   carbon
>> composition  resistor  across  the  output  of  the  pi-net  in   question,
>> and   put  a  MFJ-259/B  on  the  input.   Simply  tweak  both  caps   for
>> flat  swr  on  mfj.   repeat  for  all  other  tuned  inputs.
>I forgot to mention this back when I posted my reply on this topic.  It's a
>most excellent suggestion and works well.  

/\   But not as well as driving the real cathode with at least half of 
the rated anode-I flowing.  The g-g cathode is Not a linear resistance.  
During most of the positive half  of the driving sinewave potential, the 
cathode looks like an open circuit.  During the negative peak in the 
driving sinewave, a g-g cathode is c. 55% of the average cathode 
-  "Everything is more complicated than it looks. . ."  --  Mr. Murphy

>One more suggestion is that you
>leave the tube in the socket and tie the resistor to ground from the cathode
>pins.  This way you also take into account the input capacitance in the
>tube.  It works very well.  

/\   sound idea.  

>  Just don't power the tube up!
>Jon Ogden
>NA9D (ex: KE9NA)
>"A life lived in fear is a life half lived."
>FAQ on WWW:     
>Administrative requests:

-  R. L. Measures, 805.386.3734,AG6K,  

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