Tag Archives: multimeter

The Meter That Won The Cold War

This ancient piece of technology might be one of my most prized tools. Obviously, it’s an analog multimeter, but it has an interesting history.

It came into my possession many years ago when my dad was clearing out his toolbox, and he thought I ought to have it.

Now, my dad is *not* an “electronics guy”. As a recently retired firefighter engineer, he’s much better with flow controls and assessing structural integrity. He’s the kind of guy who would reverse-engineer those Tuff-Shed structures at Home Depot by sight and memory.

However, he had this multimeter in his tool box because he inherited it when *his* dad, my grandfather, passed back in 1986. He just didn’t really have a use for it, so it sat there for the next 15-20 years when he decided I should have it.

Now, something you have to realize about my grandfather, affectionately referred to as “Grumpy”: No one, and I mean NO ONE, was allowed to TOUCH his tools–much less USE them! I have reports that he would literally scream and throw things at anyone who dared.

Except me.

Grumpy was a complicated man. He was a tech sergeant in the army during WWII. He landed at Normandy and survived. He beat a Nazi to death with his bare hands. He climbed a flagpole under fire to tear down a Nazi flag. He was basically Brad Pitt in Inglorious Basterds.

Needless to say, he had a lot of demons. He had some very serious post-traumatic stress, but machismo and lack of diagnosis prevented treatment. (Side note: Please take care of your health, both mental and physical.)

After the War, Grumpy went to Southern Polytechnic to study electronics and got a job at the Lockheed plant in Marietta, GA (Air Force Plant 6) working on the C-130 Hercules and, later, the C-5 Galaxy.

By the early 60s, Grumpy was head of his department. His job was to check the wiring on every aircraft that rolled off the line. All of it. Every plane.

Which means that every Herc since then and every Galaxy (including the original prototype) built until he suddenly passed away of a heart attack in 1987 had its electrical systems checked off by my Grumpy.

Those planes have in excess of 5 miles of wiring inside them. That brings be back to the early 1980s, when I was but a toddler.

For some reason unknown to the rest of the family, he really mellowed out around me. He saw something in me, they say. They also say that I’m very much like him–except not so agitated.

Grumpy was an early adopter of new technology that he could use. He bought a TI-30 pocket calculator when they first went on the market in the US. He never bought a computer, though, because he couldn’t see a use for one. Typewriters were good enough.

My cousin remembers getting his hand slapped for picking up that calculator, but I had no such repercussions.

In fact, I often took it outside to play with it–in the barn–gleefully pressing buttons in the dirt. Grumpy seemed to enjoy seeing that happen. He let me play with it.

(Incidentally, I also have that calculator. I’ll tell that story one day.)

Now, back to the multimeter….

This is the Micronta 20,000 Ohm/Volt 28-Range Multitester, RadioShack catalog number 22-022. It was produced from 1967-1973 (thanks to radioshackcatalogs.com for helping me narrow down the production years) and was Grumpy’s go-to tool at work.

I’m not sure when this particular unit was purchased (if anyone has a clue on where I could find a production date, please let me know), but I was able to grab the catalog pages featuring it. Here’s it’s glorious debut in 1967

(Note the typo in the previous advertisement)

And here it is in FULL COLOR in 1968

Nearly the exact same layout in the ’69 catalog

A nice green motif for a new decade, 1970

Yellow for 1971. Notice the addition of engineers to the “Used by more…” headline copy.

Back to BW for 1972 and a $1 price increase?! Must be stagflation.

Another year, and another $2 price jump! This would be the final year that the 22-022 would appear in a RadioShack catalog. For the record, $17.95 in 1973 is $108.83 in 2021!

And here’s 1974, the page is blue because the 22-022 isn’t there anymore and all the multimeters are built with cheaper plastics so they’re sadly not as robust. Grumpy also had the 22-027 in the top right corner. That’s another restoration project for later.

So, like I was saying, Grumpy worked at Lockheed Plant 6, and his job (among other things) was to check all the wiring in every plane that rolled off the line. This was *his* tool.

The 22-022 came out in 1967, and assuming he bought it that year (I can’t substantiate this because I don’t have proof of purchase, but Dad says he remembers Grumpy getting it for Christmas of either 67 or 68), that would mean that this specific multimeter was used to test every plane that rolled off the line from 1967-1987 (or at least 73-87).

Some of those Hercs ARE STILL IN SERVICE (though, I’m sure, the original wiring has been replaced in the last 40+ years)

What’s more, the C-5 had it’s first flight in 1968, and I know Grumpy signed off on the prototype.

It’s entirely possible that this humble RadioShack multimeter was part of that assembly process, which makes it–in my book, anyway–a significant piece of aviation history.

It’s like if Igor Sikorsky’s grandson had one of his wrenches or if one of the Wrights’ progeny had some of their woodworking tools.

Maybe not *quite* the same.

Oh, did somebody say “restoration”?!

Although the multimeter is in great shape (just a scratch across the face that doesn’t affect reading), the probes disintegrated when I tested it. I’ve tried to find needle-tipped probes like it had, but I haven’t been able to find anything yet.

Meanwhile, I did find these vintage needle-tip probes on fleaBay, and they’re a perfect fit!

I also like the right-angle connectors a little better than the original straight connector. Part of me is still considering replacing the pin jacks with proper banana jacks, though.

“Knackered” doesn’t even begin to describe the condition of the original box. There’s one staple left (and it’s not really holding anything) while the rest is held together with 40-year-old masking tape (that’s crumbling worse than a bad cookie)

My first priority is to build a pouch like the ones later RadioShack products came with. Something to provide a little protection to the box itself while being a durable container for the piece.

It’s also gotta look like it originally belonged to the piece, so something that has that early 70s aesthetic.

Brown vinyl. I’m going to use this compact cassette case (another hand-me-down from my dad, actually) as the design model. It’s basically a hinged box with a vinyl wrap that’s folded and glued to look like it was sewn together. (We’ll talk about those cassettes another day….)

To start, I just ran a basic box shape, open on top, through the 3D printer. It’s just 1mm thick on each side, but that will be plenty enough to hold its shape once I wrap it.

I’m not going for super rigid here, just something to prevent the box from further incidental damage.

Fits like a glove!

Next thing to do will be to source some brown vinyl and come up with a template.

Okay, I’ve played around with the design and I think I’ve got something that will work. Hold on to your butts!

So far, so good!

The edges on the front and back are folded over and glued while the edges of the sides will wrap over the corners underneath. This will give it the illusion of being sewn together.

Also: Shout out to @HarborFreight super glue gel! It’s like regular old super glue, except it doesn’t run! Why didn’t I discover this sooner?!?

This might be my new favorite plastic adhesive.

It’s coming together! One side is a little low, but–like everything else–I’ll fix it in post!

Almost there! Just need to put a trim piece around the mouth.

All the hard parts are finished. I just need to find a snap closure for the flap. There’s probably one floating around at the shop.

After searching through several options for snaps (sew-on and riveted), I picked up a pack of these nice antique brass magnetic snaps.

With a liberal application of super glue, I think that we’re finally going to call this done!

I’m debating with myself whether or not I want to engrave Grumpy’s name on the flap. I think there’s enough room, but I just don’t want it to be cramped. I’ll play around with it some more and update if I decide to go that way.