(no subject)

[stormdog]

I just removed the meter to avoid scratching the face while moving the unit around. With it out of the frame, I noticed the date on it. I'd been hoping to find a date somewhere to give me a better idea of when the kit was sold. April 5th 1961; nifty!

I wish it stated the full scale deflection current somewhere on it.

Comments

[acelightning]

Too bad you can't find some sort of manual or specifications for the VTVM online - that would give you useful tidbits like the full-scale deflection current. Unless there's some kind of identification on the meter itself?

[stormdog]

I've done a lot of looking and haven't had any luck yet.

It sounds like most VTVMs have a very similar design. Just about all of the schematics I've found use a 12AU7 dual triode and a 6AL5 dual diode. Mine uses a 12AU7 and a 6BN8, which is a dual diode, single triode tube. It makes it just different enough to be really confusing to a newbie.

[stormdog]

This past weekend, I figured out (at least I'm pretty sure) that the reason for the extra triode is to be a high-mu amplifier for the low voltage AC ranges on this meter that a lot of them don't have. Progress!