Cleaning odd potentiometer

[Ggizzy]

Hi,

I am cleaning a Klemt Echolette M40 and have come onto the 500k ohm channel volume pots. They appear to be completely encased? And they are riveted on two corners of the backplate.

Has anyone encountered these before? Should I carefully drill out the rivets and replace with nuts and bolts?

They are labeled:

Ruwido
500k ohm lin

Thanks for any help.

 

[costis_n]

This is pretty common, old times quality pot. Good pots are completely encased like this. I have some from RFT (East Germany). If you drill the rivets, it will fall apart. The back plate is supposed to be grounded, for shielding reasons.

 

[Eli Duttman]

If the part is sealed, leave it be or replace it. While not unheard of, linear taper pots. are not usual as volume controls.

 

[Ggizzy]

Thanks!

 

[E280F]

Hallo!

This a very classical German pot used in millions of tube radios. It was also used in old tube amps.
I have opened a few of these pots by carefully drill out the rivets. After this I replaced the rivets by screws in the metric M2,4 size.
These pots have sometimes problems with the contact rivets. After soldering them the pot will work fine again.
Have a look at the photo.

Kind regards, Frank

 

[costis_n]

They are not exactly hermetically encased, you can spray pot cleaner from the front side, just over the connecting lugs, as a first measure.