[Hallicrafters] S-19R AVC problem

[Art Lebermann]

Wayne...

Try replacing C22, the AC line by-pass capacitor on the primary side of 
the power transformer.  A shorted or leaky capacitor will put AC on the 
the chassis (depending on which way AC plug is inserted in wall outlet). 
  AC potential on chassis can couple to AVC circuit through C3 (.05 uf 
cap from AVC bus to chassis ground).

ART
W6REQ


Wayne Light wrote:
> Well folks...I'm stumped.
>  
> I have the version of the S-19R that uses the 6SK7 and the 6SQ7.  It works fine until I turn on the AVC switch. I then get a loud hum and some loud whistles when that switch is turned on... when turned off, every thing is back to normal.  I've replaced about every part in the AVC circuit and exchanged a couple of known to be good tubes.
>  
> Any ideas?
>  
> Wayne
> 
> 
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