I've searched through a bunch of threads, and through Pluck's list, and can't find a resource for having my '33 BB ammeter checked out and cleaned. Does anyone have any recommendations?
The '34 one is an induction type, with a loop on back that the main hot wire passes through. They are not very sensitive but do indicate which way the current is moving... This type with the loop just about doesn't go bad, in my experience. If it looks good just clean it and put it in. They can be pried open for scrutiny and cleaning...
It's not like removing it again in the very scant chance it's no good would be hard!
Sometimes ammeters can lose magnetism. They also need to be appropriately adjusted, lubricated and dampened. With the inductive type, we find that they aren't much for accuracy, but they are very safe.