Quote:
Originally Posted by N2IXK
The ohms range test voltage on VTVMs was typically provided by a 1.5V "D" cell battery, not derived from the line voltage.
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Exactly right; I don't know how I let that fact slip by me since I have the actual "C" cell sitting right in front of me. Interestingly, this Simpson was given to me to fix up, and when I pulled the cell out I could see that it was rather dated. It is a Union Carbide Eveready "Nine Lives" with 30 cents each marked on the side. I couldn't believe it when I checked the cell and it was still producing EMF after all these years! Usually they have leaked and corroded everything long ago, but not this one. Pretty neat!
Anyway, so we are still dealing with the fact that everyday capacitance test devices these days are using a very minimal voltage in performing the test. I am pretty certain that there are vintage testers that test under load. I'm not sure how easily one might be obtained or how reliable one might be. I sort of have a rule that I like to repair and use vintage equipment, but I don't want to have to repair or restore my test equipment, so if I can I like to try to find reasonably newer stuff that would not require restoration. Given, much of the old stuff like Simpson V.O.M.s (solid state) and Hickok tube testers are pretty much bullet proof. On the flip though, I don't really want to rely on a really old O-scope unless someone has given it the once over that knows what they are doing.