Posts: 15,973
Threads: 557
Joined: Oct 2011
City: Jackson, NJ
After having attached the line cord, I checked the switch and the volume pot again. That is, I did check the switch before. Intermittent. But it's the pot that is bad. Even after restoring the wiper to rheostat contact with Fafer lube, the rheostat itself is over 3M at the nominal of 350K.
I think, a call to Mark Oppat is going to happen.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Posts: 4,739
Threads: 52
Joined: Sep 2008
City: Sandwick, BC, CA
Mike;
So if you check the resistance from end to end the volume pot reads 3 meg Ohm? I could see 1 meg maybe, if someone had changed the control, but something weird is going on, it would be more normal for the resistive element to wear out, which would men that the wiper would not make contact. If it were my set I would investigate, but then again I've had to clean out a lot of controls in farm battery radios so I'm not too concerned about breaking something.
Happy Christmas
Arran
Posts: 15,973
Threads: 557
Joined: Oct 2011
City: Jackson, NJ
Arran
The control is original. The wiper is some sort of round brass plate, that probably just digs into the carbon every time it's turned. And, yes, end-to-end is between 2M and 3M. Right at the leads. I will have to check the wiper contact again after yesterday's F5 bath dries up
but this is not expected to change the rheostat's value.
I will see if I have a stash of suitable values parts; likelyh not; the values would be from 250K to 500K or so.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.