[AMPS] SB220 Question and Reflector update

measures 2@vc.net
Sun, 6 May 2001 21:04:05 -0700


>
>Hello, well everything seems to be back to normal, no one know what
>happened.....just some sort of a glitch some where.
>I have a question and it might be beat to dead already. What is the
>easiest way to check a tuned input circuit on a Heathkit SB220 with out
>applying AC.
>Thanks Will,  K6NDV
>
The stock tuned inputs can not be adjusted for a good match with a 
solid-state radio.  For a good match, the Q needs to be increased to 2.  
The best check is under normal operation with over 50w of drive.  G-G 
cathodes act  differently than a fixed resistor.  see Circuit 
Improvements for the Heath SB-220 Amplifier in the November/December 1990 
QST.  The orig.  MS is on my Web site.  The December issue has the info 
on tuned input improvement and adjustment.  .  I recommend standing on a 
plastic matt.  

cheers, Will

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


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