My Motley collection... A Datron 1041m (Mil version) 4.5 digit DC / AC RMS / Ohms, A 1045 DC Voltmeter and a 1030A RMS voltmeter. I haven't shown the Maplin 'White Gold WG022 handheld that hangs about the bench.
The Datrons are the predecessors to the 1061 / 1065 etc Autocal family. The things I like about them are:
- Accuracy, although they're 4 1/2 digit their DC and ohms accuracy is 0.01% + 1 digit.
- Infinitely repairable, they use standard NS linear ICs and the logic is LSTTL (socketed), no CPU, no EPROMS, no NVRAM to worry about. Of course that also means no Autocal, but all the cal pots and sequences are well labeled.
- Nice readable plasma displays, but unlike the later custom one in the 106x series these use socketed standard Sperry / Beckman SP33x and 35x series.
- Same RMS performance (same Silicon) as the 106x series.
- Fully floating 10G ohm DC inputs up to 20V (10M on 100V and 1kV ranges). Much better than meters like the Keithley 177, Soartron 7150. Input current on the 1045 is less than 20pA, the 1041 is less than 5pA.
- 5 lead resistance measurement, includes Ohms guard to compensate parasitic resistance paths.
- 10mV range with 1uV resolution and 0.03% accuracy (DC). Often more accurate than longer scale meters with higher bottom range. Useful for implementing external current shunts with only 1 or 10mV drop (can't see the point of high voltage burden current ranges on bench meters).
- The 1030A RMS meter has fully switchable AC / DC coupling, switchable filters and bandwidth (up to 1MHz)
![](https://www.eevblog.com/forum/chat/show-your-multimeter!/?action=dlattach;attach=180088;image)
These can sometimes be found really cheap on ebay, probably not very popular because there are no online manuals, something I hope to rectify some time (lots of A3 drawings to scan).