Help With POTS

fab4 · Post by **fab4** » Sat Apr 14, 2007 8:16 am

Hello - I really need some help with identifying some POTS I found in an old parts box. They don't appear to be Ric parts as they have a split shaft. Numbers on the POTS are: These numbers are on the top of the pots 1346538 R - 22 1 MEG

The other pots have the numbers on the side and they are: 1346539 R-21 250 M, 1346801 R-21 250
1346552 R-22 1 MEG and 1346506 R 21(?) 250

Thanks in advance for any and all help in identifying these and dating them if possible

jwilli · Post by **jwilli** » Sat Apr 14, 2007 8:45 am

Len, the first 3 digits indicate maker. 134 would be Centralab.
The next two digits represent the year. 65=1965 86=1968.
The next two are the week. 6539 would be 1965, 39 is the 39th week. I'm not sure what R-21 or R-22 means.

ken_j · Post by **ken_j** » Sat Apr 14, 2007 1:58 pm

Here's the link for the codes.

jwilli · Post by **jwilli** » Sat Apr 14, 2007 2:13 pm

Thanks Ken, I wanted Len to think that I knew this info off of the top of my head......;-0

Actually, I did know everything after the manufacturer's code.

elysrand · Post by **elysrand** » Sat Apr 14, 2007 2:44 pm

The R-21 and R-22 refer to the taper for this manufacturer and this potentiometer, or the rate at which the resistance changes as the center wiper is moved across the resistive element from one end to the other. Some popular tapers are audio, linear, and logarithmic. There are lots of other, more obscure tapers.

The values follow. 250 means 250 kilohms, or 250,000 ohm. Similarly 500 would mean 500 kilohms and 1 MEG means 1 megohm, or 1 million ohms.

fab4 · Post by **fab4** » Sun Apr 15, 2007 5:26 am

Many thanks to everyone for the information - I am educated !!!