Join Date: May 2010
Location: was Chicago IL, now Long Beach CA
Simpson 312 VTVM
eBay did me OK, I think. Does this thing need a battery inside, or does everything including the ohms scale run off the 110VAC wall plug?
I picked up a Simpson 312 VTVM for working on tube guitar amps. Two years ago when I was trying desperately to keep my house, I sold all my bench equipment. I never had a VTVM, and most of my other stuff was Heathkit kits I built, which didn't perform as good as what I could have bought new assembled for less money. But my dad had a few VTVMs I always coveted. Surprising to me I'm excited about buying used tube test equipment that's probably 50 years old.
I haven't opened up its case yet, or even plugged it in to test whether it works. But I already love the LARGE analog needle meter! Much better 'feel' for a varying voltage than flashing digits and moving decimal points, or some teensie bar-graph. And Heisenberg be damned I imagine it doesn't load the circuit being measured!
It seems almost all the Simpson 312 meters have broken or missing fittings on the meter end of the probe lead. And the thread on that fitting is fine and somewhat non-standard. So people generally recommend disassembly and replacement with something like perhaps a BNC. Anybody know how difficult it is to disassemble one of these things? I have the original probe, but no cable fitting at the meter connection.