01-31-2010, 03:43 PM
Get an analog ohm meter and see where the variable capacitor is shorting out. Ususlly it's a bent leaf on one of the ends. If you can slip a piece of paper in, you should be able to find it. Otherwise there may be crud in there. And if there are trimmers, take 'em apart and clean the contacts and micas (very carefully, they are real fragile.) I usually blast away with deoxit, put a paper towel underneath, and wait a day.
If there has been trauma to the capacitor, as in a bashed in knob or some rough handling, mre severe actions might be necessary. There are some heroic examples on this forum, including mine, which is taking the D**n thing off, and boiling it for a while and then regreasing the bearing when it dries out.
Finally, look for something really simple like a rubber coated wire that has become bare and is shorting.
Good luck.
If there has been trauma to the capacitor, as in a bashed in knob or some rough handling, mre severe actions might be necessary. There are some heroic examples on this forum, including mine, which is taking the D**n thing off, and boiling it for a while and then regreasing the bearing when it dries out.
Finally, look for something really simple like a rubber coated wire that has become bare and is shorting.
Good luck.
