I'd been looking for a decent low-range analogue ohmmeter for a while, and this little meter appeared at a recent amateur radio club surplus sale. No-one else was interested, so for a mere £2 it became mine.
The green Bakelite case was undamaged and in relatively good condition. The main problem was that the old 1289/3R12 4.5 volt 'flashlight' battery had been left inside and had leaked, corroding the positive terminal to the extent that it snapped right off as I was cleaning it. I cleaned up the remainder of the 4BA stub with a rotary wire brush, then using a 60 watt iron I soldered a 4BA solder tag onto it. A couple of short leads and a 3 x AA cell holder with batteries returned the meter to working order.
This is the three terminal model which has two ranges, 0-3 ohms and 0-30 ohms, and was intended for use with special test leads, including a dual positive lead having an in-line battery switch. I searched the Forum, found
this old thread from 2012, and with some advice kindly provided by Forum member Trevor ('Noble Kiwi') I made up some new test leads. Rather than using a switched battery probe, I made up three leads with crocodile clips. I discovered that the resistance of the common negative lead is critical, which is not surprising since it appears in series with the resistance under test. I tried several lengths of cable and probes before settling on one which measured less than 0.1 ohm, and was delighted to find that the meter is very accurate when testing several resistors ranging from 0.1 ohm up to 30 ohms.
This instrument has already proved itself very useful!
Phil