my deal of the day: triplett model 310

[linux-works]

found this little pocket DMM (oops, not a DMM, just a regular multimeter, lol) at my local shop, today (halted).  looked interesting.  I like old analog meters, especially cute little ones.

"how much for that triplett in the glass case?"
"don't know.  no price on it."
(two salesguy discuss it amongst themselves)
"how about $10?"
"deal!"

dc volts is spot-on, and so is dc-current.  the resistance ranges need 1 semi-normal battery (1.5v N cell) and a strange odd cell (15v cylinder cell, almost like a 12v 'security' battery).  good that the odd cell is still available on amazon ($10) and that N cells are mostly easy to find.  the N cell does all the R ranges except the 'x 1k' range, so at least it can do basic continuity with just the N.

it takes mini-banana jacks (which I don't have any of) but other than that, its one very cute little meter.

I was extremely surprised to find it still available, new! parts-express has it, as do others:

http://www.parts-express.com/triplett-310-compact-analog-vom--391-040

it seems the model first came out in the mid 1950s.

http://www.radiomuseum.org/r/triplett_310_vom.html

and costed around $30

[w2aew]

Nice score! Those are nice little VOMs. There were several variations over the years that had different battery types, battery access, mode switch and other variations.

[Electro Fan]

Is the Triplett as accurate on the far left side of the meter range as it is in the middle and toward the right side?  I've found some other (less expensive) analog meters to be ok toward the middle and right but not so accurate to the left.

[linux-works]

I'll do a full test on it when I get a chance, but from what I've read about this 'mighty mite' unit, its supposed to be pretty accurate across the scale.

50+ yrs of making them.  I can't get over that fact.  plus, that they find it to be profitable to still make and sell them.  I wonder who the target market is?

[retrolefty]

At the refinery I worked at this meter was part of the basic tool list provided for all the electricians for decades and still being used up to late 90s when they switched to fluke as the basic meter to be issued. The problem was that there is little or no protection built into the meter and the electricians would send them to our instrumentation shop for repair or replacement. We had several boxes of blown up triplett 310s as there was just no economical way to repair them. Of course most failures were the result of 'operator error' but it was (and still is) a very nice meter. It's small size and weight were particularly liked as it took up little space in a tool pouch when one went out to the field or plant. There was a very nice leather case designed for it and would be nice addition if one was collecting this classic meter.

 Simpson 260 was our favorite bench meter in the instrument shop until the DMM became available.

[linux-works]

a few weeks ago, I did buy my 2nd simpson 260.  also found a nearly new rolltop cage kit and that was a fun find.

there are back-back diodes on the meter movement but no other protection.  so, you have to start high and dial down manually.  but that's fine, just rotate the knob all the way left for DC and all the way right for AC and you hit max scale.  they thought of user interfaces *well* back then.

I need to clean up the switch contacts or lube them.  it takes a bit of force to move the plastic dial around and maybe there is a clean/lube procedure somewhere?

[elliott]

I've got the Triplett 630, I like it a lot. I wouldn't mind picking up a 310 and 666 in the future. They made some very high quality meters and I've always liked the Bakelite analog meters. The 630 is also still in production.