Graham Green had a stall at Make Change yesterday. Graham’s the former manager of Active Surplus, the much-missed Toronto surplus emporium. He had some military-surplus multimeters that hadn’t seen daylight since I was in school. That’s a while back: this (unfortunately) was #1 the week I left school. So I bought one of Graham’s meters just to see what was inside …
Would I recommend the Soltec as a general purpose meter? Not really. There are more capable multimeters available for about the same price, and you don’t need to go as far as the unbelievably expensive Agilent DMM I use (or even the strictly ornamental analogue ex-Forces Bach-Simpson 635 multimeter that graces/clutters my workbench). It would need a video to show where analogue meters excel: in showing changing values and getting a rough idea of the limits. It would make a great battery tester, or — if coupled with a micro-controller with PWM or DAC ouput — part of a demo rig. If nothing else, it’s a great way to learn how to appreciate modern test gear and all it does for us.
I’m probably going to regret this, but here’s a scan of the Soltec HM-102s manual:
They’re maybe not the quickest (the 4 MHz Saturn processor chugs sometimes, and wanders off to clean up memory when it feels like it), the display is downright chunky these days, but they have everything that a scientific calculator should have. The keys have a good action. It just works. Yes, your smartphone has hundreds of times the processing power, but it’s not specialized to the task. The HP48 is.
If you’re feeling really nerdy, you can run an HP48 (a GX, not the G which I have) under Linux using x48. Jeff has some useful tips on installing x48 on newer ubuntu versions (though you don’t have to do the font thing under Ubuntu 13.10).
Building it is a small matter of ./autogen.sh ; ./configure ; make ; sudo make install. To run it, you’ll need to install the GX ROM image to ~/.hp48. The first time you run it, I’d recommend running it from the terminal with: