Bad pots.A cure?

[coil1234]

In my dealing with old test equipment it was normally tarnishing of the circular wiper ring and its contact that caused intermittancy, if the pot could be dismantled my weapon of choice was a typists eraser, pencil shaped but with an ink eraser core, very useful for burnishing all sorts of contacts.
However with the demise of the manual typewriter, they are now unobtainable, can anyone suggest a source?

Regards Mike Andrews

[igranic]

.... my weapon of choice was a typists eraser, pencil shaped but with an ink eraser core, very useful for burnishing all sorts of contacts.
However with the demise of the manual typewriter, they are now unobtainable, can anyone suggest a source?

IIRC ink erasers contained fine abrasive particles.

A readily available modern alternative is the Garryflex Abrasive Cleaner. These generously-sized rubber blocks containing abrasive particles are available in four grades, and can be cut to appropriately sized/shaped pieces with a sharp knife. I use the Fine 240g (brown) grade for contact cleaning and general metal burnishing.

They are available from Proops Bros (bottom of page), online auction sites, and tool suppliers (search for "Garryflex").

Edward

[Sideband]

One old boy I knew that sadly is no longer here spent 50 odd years in the trade. Whenever he got a noisy pot, he would open it up and clean it with ordinary switch cleaner. Then he would pack it with petroleum jelly (vaseline) and reassemble. I've still got one of the pots he did in a DAC90A and it is perfect. I've never done this myself and it may not work with all pots but if you have nothing to lose by trying......


Rich.

[Boom]

I thought I was the only one who did that. It has worked well for me too.