i wouldnt go to murex you would need very deep pockets at their prices!maplins or look on e-bay,only be a few pounds for one.if i rember thay are panel mounted type.
You will need to get All the info off the sus pot because there are generally to types one is log and the other is liner (if I recall, it's been a while since I've had to replace a pot) difference is one gives a curve of resistance adjustment and the other gives more of a streight line if that makes sense. One tends to be used as a volume control. If you look at the markings they will be somthing like "10K log" or "10K lin" If you fit wrong one you might find most of the control will be at one end of dial or the other
both are set to zero and clicked off, you can get it to speed up by holding the switch to one side, but it slows down as soon as you let go, not very predictable to weld with, clarke 100en pressed into service in the mean time, as my portamig is tucked away in my garage
well new potentiometer fitted, new knob with a screw fitted, as the old one was a splined, hacksawed to length and a flat sanded onto the new one and guess what
it now works fine, good as new, many thanks for the help
Well probably they'd have pots mounted directly on a pcb to save wiring labour, but a bit of reverse engineering, flying leads and possibly a new hole in the panel would sort it if you couldn't source the mounted original pot.