12-06-2020, 05:23 PM
I took apart the volume control today and it answered a lot of questions. The surface that the wiper contacts has the resistive conductive material missing from the 2/3rd mark on up, When you pass that mark the distortion occurs which also means that the wiper and capacitor are the only path, no resistive path to ground. No wonder the IF has been acting strange, it needs a complete path to ground. Also a clue that now makes sense. When trying to tune this, if your screwdriver blade touches the trimmer capacitor in the IF and the edge of the can at same time the reception gets really good -- I suppose that is helping the IF path to ground. Looks like I'm going to need a 500K potentiomer with a 1" shaft with cutout for the knob. Do people usually buy a a solid shaft and cut out/grind the place for the knob?
