[Elecraft] Recommendations for Multimeters

Mark J. Dulcey [email protected]
Fri Oct 25 14:57:01 2002


glen houghton wrote:
> Just getting back into electronics and thinking about building an K1 and if the goes well I might try a K2 or have someone build it for me.
> 
> What is the best multimeter for building radio kits etc? I see a larger variety than I had in the past. Anything special I should look for? PC interface is this usefull or not?

There are so many choices out there that naming a single "best" meter would be impossible. But I'll offer some advice anyway.

First, just about any DMM (digital multimeter), even the ones that sell for under $10 at hamfests, has enough capability and accuracy for all the measurements you will need in an Elecraft kit, with one possible exception that I'll get to. This is NOT true of a VOM (volt-ohm meter); those cause enough circuit loading to make some measurements inaccurate. (A VOM is an analog meter with no active circuits.) An old VTVM (vacuum tube volt meter) would work fine, but they're collectible these days, so you would probably pay more for one than for a decent DMM.

What you get with a more expensive DMM is a bigger display, a more rugged case, better probes, more accuracy (not necessary for the Elecraft kits, but it might come in handy for other uses), possibly more capabilities (capacitance, inductance, transistor gain, temperature, and frequency counting are all things that I have seen), a brand name, and a warranty that actually means something.

So, why might you want to pay more?

First, a bigger display is nice. It's easier to read. If you have trouble reading any of the portable meters, even the large ones, you might want to consider a bench DMM; they plug into the wall and have glowing digits of one sort or another. Most of them are horribly expensive new, so you'd want to look for a good used meter at a hamfest.

A more rugged case is good. The meter will last longer. Better probes will also last longer; you can replace cheap probes with better ones, but that's an extra expense that you can avoid if you buy a meter that comes with good ones.

Capacitor measurement is one extra feature that I'm a big fan of; it saved my butt a couple of times when I was building my K2. Some modern capacitors have very difficult to read markings, like the ones with tan bodies and red digits in the K2; putting them on the meter can help you figure out which parts are which.

A feature that I haven't used personally, but that other people here have praised, is an "analog" bar graph in addition to the digital display. It's handy for peaking and nulling adjustments, and often updates more quickly than the digital display on the same meter.

One feature that I personally DON'T like is autoranging. I prefer to know what I'm measuring before I measure it, rather than having the meter make decisions for me. Some DMMs, particularly portables, are auto-ranging only; other are switchable auto/manual, and some are manual-only.

If your budget permits, you might supplement your DMM with an analog meter. (Even a VOM is fine, so long as you are aware of its limitations; mostly, you don't want to use it for exact voltage measurements when you're doing the voltage checks or troubleshooting in your Elecraft rig.) They are still handier for some measurements than any digital meter. They're expensive new these days, so watch the hamfests.

So what do I use? At home, I use a Beckman Industrial (now Wavetek-Meterman) DM27XT. It's a full-featured DMM that includes inductance and capacitance scales. It's held up to 15 years of use here, including the building of my K2 and all the modules. The Harvard classes based on the Art of Electronics use the very same meter in the classroom labs, and they have held up to years of student abuse, aside from the fact that the students blow a lot of fuses. (I've never needed to change the fuse in my own meter.) For quickly checking things out at hamfests, I use a $7 hamfest special; it's smaller than the Beckman, and I'm not out much if I lose it. Finally, I also have an old Radio Shack VOM that I built from a kit about 25 years ago; it only occasionally sees use these days.