Triplett 310-C Type 3

[gowf67]

Hello, I found this Triplett Model 310 at the local pawnshop and they were asking $29 for it. We tested it and found it would not register when trying to test a AA battery so long story short they ended up giving it to me for $1. I took a quick look inside everything seemed to be in pretty good order I cannot see if there is a fuse however. It's a really nice little unit and I'd like to get it working any ideas?

[gowf67]

Actually it works once I put it back together, but it's a bit dicky to borrow a phrase. I compared a new battery with my Fluke 79 and its off by a volt or so. Also I had to tap the leads against the battery to get it to work. Oh well, maybe I'll try some new leads from eBay. Does any know where/if those oddball batteries 15/1.5v can be found?

[tautech]

Does any know where/if those oddball batteries 15/1.5v can be found?

The 15 V'ers are available, but aren't cheap.
IIRC ~US$20.
They're normally only required for the high Ohms ranges, the 1.5 V cell does the low ranges.

But easy to bodge one up with 5 x 3V button cells, some copper tube to lengthen to correct measurement and shrink sleeve over the lot to hold it all together.

[gowf67]

Thanks I'll try that. Also I see where my missing volt went, I need to zero that sucker.

[SeanB]

Dicy readings will be dirty contacts on the range switch or the connectors, and the low reading will be the usual carbon composition resistors inside going high in value.

[tautech]

I have been caught out checking the 15V batteries for remaining charge with a DMM.
They might seem alright, but load them with 1K or a moving coil meter and you'll really see they if they are OK.

[SeanB]

15V battery is also easy to DIY by using 2 GP23 12V remote batteries, and taking them apart to use the inside coin cells. Simply slide 9 of them into a small tight fitting paper sleeve, and put the end connectors from one of the donors on the ends, and roll the paper around then to stop them falling out. Then place in the space where the 15V battery went. If the new cell is a little short add an extra cell, as the voltage range will still work with 1V5 more without hassle, and will work longer as the batteries age.

[gowf67]

Thanks guys for the responses, I've done a little more tweaking. I found a 1.5V LR1 which is a NEDA 910 type at our local Walgreens (Chemist) and it works OK for resistance checking <1M. I used some contact cleaner on the lead sockets and now they are much more responsive. Probably should take it apart again and work on the main selector switch. The original NEDA 220 type 15V I checked with the meter itself and it still has 11V which I would imagine for all intents and purposes is dead, however, I found this: http://amzn.com/B009CCBGOG and am curious if anyone had any experiences. All in all, I'm thinking paying $1.07 for this with tax was a pretty good deal since they are in the $150 dollar range new. It still impresses me how solid the feel and switching mechanisms are, it's almost like they built this to last or something, how crazy. I'm guessing this Type 3 is early 70's? Not sure. Others have mentioned converting it to use a 12v battery which are cheaper but maybe I'll consider that later.

[linux-works]

I have 3 of those meters.  they are small cute and cool.

for one I did pay for the amazon proper battery.  it was $10 or so, not all that much.

or, you can ignore the resistance ranges and go battery free on the unit