Crackling audio potentiometer on Roberts Radio 200

[John Earland]

Hi, Just thought I would just post this for interest. I have an old R200 Roberts Radio. Works well but a really bad pot meant trying to adjust volume was a nightmare. So instead of replacing the pot I opened it up and used a pencil and scribbled all over the plate. I don't know how long it will last but at the minute it works perfectly! Any comments are welcome.

[paulsherwin]

Yes, well known bodge which may continue to work for ages.

[John10b]

Yes that was done back in my days on the bench, can’t say how long it would last.
John

[G6Tanuki]

I've done that in the past, and it's a good way to 'extend' the life of a failing pot.

One fault I also seem to be seeing more and more is contact-failures between the carbon-deposited pot track itself and the metal tags/rivets at the track ends. When this happens - usually when the volume-control is at the bottom end of its travel - the result is the radio suddenly delivering near-maximum volume.

Sometimes you can *g-e-n-t-l-y* extract the track and the tags as one from the pot-body then give them a tap with a toffee-hammer and a drift to re-peen the rivets and restore electrical continuity.

[Goldieoldie]

I have used conductive paint on the end rivets and track