The original pot when actuated would take the meter, a 90° arc, from 0°-30°, then to 0 then to 60°-90°
I already knew the about the strange double pot configuration years ago.
I messed about with another 50K WW pot, but it is smaller in diameter.
I'm going to have to do some mechanical work to bung it in the original back half. Something I don't want to do. AT ALL.
I'll have to get creative with J-B Weld and metal. The worst part is the front shaft is too short. Enter a shaft coupler. I would not want to show what that all put together would look like.
Anyway, getting back to the original question, I still need an opinion why the pot would burn.
The appears to have no discernible current or HV to cause such a thing.
Open for analysis and opinion.
Here are the photos from this morning.
They will show:
1) The original unmarked (manufacturer) naked 50K pot.
2) The full open original.
3) The original pot wiper burn.
4) The original back (5K) half with the possible complexity of the replacement conjoining.
5) The original back (5K) half with the possible complexity of the replacement conjoining.
6) The original back (5K) half with the possible complexity of the replacement conjoining.