by Oldiron » Mon Aug 06, 2012 1:43 am
You should be able to read the resistance with an ohm meter unless the winding is open. Most of the time when a pot goes bad it is the wiper arm that gets dirty causing the pot to get jerky or intermittent. What you need to know is total resistance across the pot. The normal practice is to use three taps on the pot the outside two will read total resistance 1k 5k 10k etc close to an even value. Then the center tap takes the adjusted resistance to vary a voltage. For what you want to know that measurement is irrelevant. If the outside taps (the tabs the wires solder to) read say 5200 ohms you want a 5k pot 12000 ohms a 10 k pot. Now be sure you unsolder one of the outside leads BEFORE you take your reading as any resistance in parallel will mess up your readings.
Or you before you do that see if the pot is marked with a little number like 5k or as high as 10m printed on the pot. Most manufacturers will put the value on the pot sometimes as part of the part number. If you find a part number Google it and you should find the data for the part. The people who build radios don't normally build components like pots, resisters, op-amps and the like so look for a part number.