[Hallicrafters] SX-42 audio

[jeff]

I'm woefully incompetent at being a tech, but you can follow some basic
troubleshooting principles to (hopefully) arrive at the culprit.

Definitely download the manual from BAMA or wherever - this is your best
clue.

Try working backwards.  If you hear speaker noise, as you indicated, the
speaker's functioning.  If you have a signal generator of any type, you
can put it into the circuit starting toward the end.  It will pass
signal until a certain point.  This is the general area of the fault. 
Do you get signal through from the output tube?  Try moving towards the
front of the circuit.

Very simplified, but that's all I can offer.


Remember - the electronics tech who is self-taught has a fool for a
student :)