Vintage VOM Rectifier Circuits: A Rather Late Explanation 

ssnoc, yes, when I have a bad motor that cannot be simply replaced with a new one, I know exactly how to accomplish getting it re-wound......I take it (or send it) to the nearest professional motor rewinding business. Usually, just buying a new motor is less expensive and faster.

Some of the meter rectifiers are copper oxide. Each diode has a low reverse voltage so sometimes they are stacked and look like mini selenium rectifiers dipped in paint to hold them together.

Wonder how many rewinding shops are left. We had one here in NE Minneapolis that was in business since the 1930s. Went there in the mid 90s. He still had most of his original equipment. Kind of like traveling in time when you went in there. The owner has passed and the shop is a vacant lot now

@@youtuuba - Yes, I agree it is cheaper to just buy new - I was just interested in the actual process because it seemed somewhat complicated and just wanted to understand it better.

When re winding, look at it magnetically. In the very very beginning no one knew/understood that electric current porduced a magnetic field untill Faraday figured out induction. Magnetically coupled current if you will. Winding them is a pattern once you understand its not that bad. It's just actually getting the coils in the iron that can be tricky! If you can get it to around 780°F for an hour or so you'll burn of the old varnish, and if you have a sand blaster. Blast it with it get the inside of the iron were the coils go all away around clean very clean! After that you can use a thin rattle can varnish to pervent rust. You'll need to create a coil jig for the coils too. After you've wound it and connected the coils/polls correctly dip in a varnish, and bake. May take multiple dips depending on the varnish you use, and the voltage ratings. Get good magnetic wire with great insulation too!