So I did an ebay search in consumer electronics for "focus control"
There are lots of focus control assemblies for 70's-80's tv sets. However I am not at all familiar with tv sets of that era.
Here is a url to the search I did.
https://www.ebay.com/sch/i.html?_fro...LH_TitleDesc=0
It came up with a lot of hits but you have to sort through about 170 items. A fair number are focus assemblies for tv sets, but there are also some "Ford Focus automobile controls". The problem is that I haven't any idea if any of these would have resistance values near what I am looking for in the area of 50 meg.
Do any of you younger techs have experience with the actual values of pots in these tv focus assemblies.