This unit was purchased alongside the unit shown in the first part of the series because, at first glance, it appeared to be in somewhat worse condition than the other device and had the potential to be a donor in case something was wrong.
The face on this one is somewhat different, with the legend being areas where paint is not, instead of the other way around.
This one has all the correct knobs and input jacks, unlike the other unit. The face is also free of scratches, and has a nice black-framed meter instead of the later, clear meter the other unit has.
The back shows some scars, however. Lots of rust.
Since the whole side isn’t rot, I assume it just received some damage at some point and then sat in a wet environment.
The top is similarly rusty, and is missing it’s handle. Well…there was a small piece of leather left, but that’s it.
Of note here is the cabinet is not the same as the other one. This unit has a simple rim that creates a dish the face sits in, not a rolled out area like the other one.
Inside, we have the same rat’s nest as the other unit, with the same amount of ‘lectric sketti. That must have been provided by Precise, as these were sold as kits. Some of it is good, some of it is quite nasty and sticky.
Instead of an old RCA battery, this one has a lovely early 70s vintage Radio Shack battery. Probably dates the last use of this device to the mid 1970s, and it was probably replaced with a FET or early digital unit, assuming the owner had use of a meter.
The cordset was in excellent condition, of course:
It was removed and stored in the trash can.
Jay Hooks makes his appearance in this unit as well, so this may have been something needed because of the lead length. But those old blue carbon film resistors aren’t present, this one has slender red ones instead.
The tube side is the same as the other unit. The meter body itself is quite rusty, so this thing sat in someone’s damp basement for years.
Of note is the filament burnoff on the 6X5, just like the other unit. Either these are hard on that tube, or they were just on all the time. Who knows?
Does it work?
Again, sort of.
This one also had a good filter, so I cut off the remaining cord stubs and used my death cheater to power it up. It comes up, and is more stable and accurate than the previous unit. That’s not saying much, it’s still in need of major repair.
I’m not sure where these will go, which one (or both!) will get rebuilt. Stay tuned!
Much like the EICO 249, this meter features your standard measurement options, as well as the giant meter face. This example is dirty, but in decent shape for the age.
The back of the unit is nothing special. The cord simply runs out of a hole and is strain-relieved inside.
Inside, we have a wiring nest.
There’s our friends, those blue carbon film resistors. Jay Hooks makes an appearance as well, although it’s done in a much nicer way than the EICO 950A was.
The control potentiometers are well blackened, as if this device spent some time in a wet or harsh environment.
Here’s our old friend, the RCA battery for the ohms function. This thing hasn’t been touched for a long time.
And some cool old C-D capacitors. Everything in here is disc.
I’m not sure if this unit was a kit, or if it was a factory build. Everything is covered with spaghetti, so if it was a kit build it was well done. I do have another example of this unit on the way as a donor, so we’ll see if it’s built in the same manner. I will say that it has some parts that have been replaced over the years, so who knows.
What makes this unit unusual? This one has 4 tubes.
It has these tubes:
6X5 as the power rectifier - no selenium here!
6SN7 as the input isolator/amplifier
6AL5 as the measured signal rectifier
0A2 as a voltage regulator
That last one is the odd man out. This device has a regulated power supply, so it should be somewhat immune to line voltage variations - something other VTVMs of the era had trouble with.
Does it work?
Sort of.
I did some quick checks on the unit, the filter capacitor didn’t seem shorted, so I plugged it in raw. The tubes have a lot of hours on them, but they lit - I didn’t see the voltage regulator fire so something is wrong in there. It does measure, but it’s way off and started to drift all over in the few minutes I had it up. So, it works, but is not operable as a voltmeter. But it does work, so it’s a good restore candidate - and it will have it’s time on the bench at some point. Stay tuned!
The 2026 Cincinnati Hamfest happened this weekend, and size-wise it was about as big as last year’s event. I spent just under 2 hours wandering the grounds a couple of times, and picked up a few things.
While it did rain, it held off for quite a while. Prices were generally pretty good, but there was one guy that was selling stuff that made me question what was going on - including someone’s printed-from-the-internet manual copies for $10. I guess you were paying for the “Estate Sale” sticker. not sure what that had to do with it, but it’s free on BAMA. I seem to remember this booth from last year, and it was the same…my companion and I both looked at the stuff and said what? There was also the usual assortment of “I bought it at this price!” prices on things, but you can get it for less new.
There was one of those little tester boxes I wanted to take with me, but the guy said you have to take this big box of consumer cables with you. I didn’t want to carry 30 pounds of F-connector and RCA cables away just to toss them in the trash - and in the trash they would have went.
There wasn’t much else I wanted to take home other than a HP334A, but I have no use for that. So it stayed.
A couple of anchors. I took the rowboat anchors.
These weren't well priced.
Some big old rack mount units.
A lovely Majestic console.
I took the little Welch ammeter.
Still plenty of these around.
Some Tek chassis units.
I wanted to take this but not the giant box of cable with it.
In all, a pretty good show. I went with a friend, we went to a local place for lunch that we both like, and ended the trip with a stop at Jungle Jims.
The Cincinnati Hamfest is happening this weekend, Saturday, August 15th at the Clermmont County Fairgrounds, just east-ish of Cincy. I went to this show for the first time last year, and it was a good regional, with enough different stuff that I’ve decided to go back this year. See you there!
Cincinnati Hamfest
Saturday, August 15th, 2026
8A-4P
Clermont County Fairgrounds
1000 Locust Street
Owensville, OH 45160
This unit was purchased at the Cuyahoga Falls Hamfest in 2022, and has sat around for a while waiting it’s turn on the bench - primarily because I knew the entire thing, range switch and all, would need rebuilt. While that seemed formidable at the time, in reality it wasn’t that bad.
The device had been purchased “rebuilt,” and I knew it probably wasn’t. And…it wasn’t. The inside had new components, but they were wrong values, wrong voltages, or in some cases, just defective components. I’m not sure how the device worked, but I had only tested the DC section and found it to be operational. The defective components are in the AC side of the device, and that’s not as important to me as the DC side is. The ohms side isn’t important at all, so I didn’t even put a battery back in after completing the build.
I did get a donor unit, which was helpful - the range switch came from it, and allowed me to pull parts, drop it in the ultrasonic bath, and get a good clean part to start with. Resistors had to be made from standard values, as the oddball stuff that EICO used were not available from normal sources. That wasn’t any real issue, it just required using some calculations to arrive at the needed values. There are plenty of calcs out there that will allow you to generate unusual values from standard ones, if you need such a thing.
Past the range switch and it’s rebuild, the rest was a teardown and replace. A couple of resistors had to be made, including a really strange 82MΩ unit that ended up being created from 4 other values, and covered in shrink.
The before picture:
The after picture:
Almost all of the wire and cable were replaced save a few jumpers, and of course the transformer wire. The capacitors were purchased as a kit from an eBay vendor: https://www.ebay.com/itm/116116838477 named “Affinity For Artifacts,” and resistors were all made from standard values in series or in parallel using a calculator that I found online: https://mustcalculat … s/resistorfinder.php.
Problems during the rebuild
The first problem was that of the 12AU7 socket. Pins 4 and 5 of the tube are connected together, tying both ends of the heater together. This effectively gives you a 6.3VAC tube. When I purchased the unit, these two pins had a massive solder blob on them. It wasn’t just careless assembly, the socket pins were broken and the previous owner had coated everything with solder to keep the pins in place. That was a simple socket replacement. While it did require drilling out, it wasn’t a terrible job and didn’t take long to do.
The second issue was that of how the AC was run. Originally, it flew up to the switch and met the transformer lead, also on the switch. The other side was on a terminal strip that connected the 9.7Ω battery resistor, and then to the battery terminal. I didn’t like this, so a larger strip was installed. The AC comes in to a terminal. One side hits a safety capacitor and the transformer, the other side connects to a twisted cable that flies up to the switch and back to the safety capacitor, which is also the other side of the transformer. The hot side is switched to avoid having hot anywhere other than the one terminal when the system is powered down. These two lines are twisted together with a ground line as a drain to try an minimize noise.
The last issue was the resistors. While it wasn’t hard to replace them, there wasn’t any way to leave some resistors in place. The old carbon film resistors will change when you hit them with heat, and that’s something I discussed during part 10. The 82MΩ resistor had to be made from 4 resistors as values this high are hard to find, and the 9.7Ω should have just been a 10Ω instead.
Past that…the rest of the device was a simple rebuild. I did regrease the switches with some dielectric grease and contact cleaner before final assembly, just because they were cleaned in the bath beforehand. Any grease there was old, and was removed beforehand.
Testing
The thing to remember about this device is it’s an analog meter. That means it is only as good as the accuracy of the meter, and if your meter is not accurate or is not linear, then the measurement is not going to be as accurate as you want it to be. In this case, something in this device is not linear - that may be the tube response, or the meter itself.
During testing, I was able to get the device to have a decent degree of accuracy in the first half of the scale, and not much at all as you approached the upper range. That’s an analog meter for you - it’s good enough to get you there, and a couple of volts at 300V wasn’t going to hurt you. I may change the 12AU7 out later just to see what happens, but for now - I’ve acceopted it as it is, and it is an analog meter.
However - this device is like all analog devices of it’s time, there was a resistor in the probe. In this case, a 1MΩ resistor that acted as part of the divider ladder. It really needs that resistor in order to be accurate, so this could explain some of the deviations. I’ll probably make a probe for this with that resistor at some point - but not now.
What did this cost new?
The device was $40 in kit form in 1963. Here’s the Radio Shack catalog page for it, back when rat shack sold this kind of thing:
That’s about $440 today!
Anything else?
Here’s a couple of pages of data that were created during the rebuild.
That’s the calculations I used to arrive at the replacement zener in the selenium circuit. I had 30V specified, but 20V actually worked better.
That page was created during the 82MΩ resistor build, and will show up in a video.
That’s all. This wasn’t as bad as I thought, and I now have a large face analog meter with a lot of cool to sit on the bench.
What’s next? A couple of kits and a Heathkit scope…stay tuned!
If you hit wereboar.com yesterday (13th) then you’ll have noticed that the site was offline.
Turns out there was something happening at the data center that hosted it, apparently a fire knocked out some electricity which took down the chillers and then the hosts, subsequently, the site. It’s all back up and running now, but there may be some short outages as things are brought back up or tested. They’re still asking us to be patient while they do testing and re-launch.
In the meantime I’ll just put this fire over here with the other fire. Stay tuned for more good junk!
As I’m primarily interested in this device as a DC meter, I did a quick calibration on that section. Before that, I greased the detents on the switches and ran a bit of deoxit on the metal portions of the wafers.
This device is supposed to have a 1MΩ resistor in line with the probe, all in a coaxial cable shell. I do not have that, so this may be a little off. I believe the probe for the EICO 242 may work, so we’ll see.
The manual suggests calibrating the DC range at 3.1V, or “the voltage from two fresh flashlight batteries in series.” Ok, sure. Let’s set the power supply at 3.1VDC, measure it with a known good digital voltmeter, and dial it in using the control on the side.
That’s pretty good for an analog meter. If I replaced that cal pot with a 10-turn, I could probably dial it in even better, but that’s not necessarily worth it. I’m happy with the result.
I did check the AC briefly, it does work, but I need to get some other devices set up to do that. However, the meter works, it is as accurate as you can get with an analog meter, and it’s ready to go into service.
Most of the parts in this device had been replaced at some point - except for the voltage divider on the range switch. For the most part, with the exception of a few in the chassis, that’s all I’m going to test.
Some of these parts came from the donor unit that I had as well, and we’re not worried about them.
Here’s the two things we’ll be testing.
This is the original range switch, as well as a couple of resistors that the previous owner made. In particular, these are R28, an 18MΩ, and R29, an 82MΩ. Or, they’re supposed to be, that is. The 82MΩ was made up of parts that totaled 57MΩ.
Here’s the measurements:
You can see that most of the parts are…ok. A decent amount of them are out of tolerance, but not terrible for the age. However, the 82MΩ part is open. I tried multiple meters, and both of the resistors in the pair are open. I’m not sure if this is something that happened during operation, or if the guy picked them and put them in without checking. In any event, one of the resistors in this pair is obviously of the correct vintage, so who knows where it came from.
So…why did these get replaced? Some of them are good! Don’t touch them! etc, etc.
I would have loved to do that, but the problem is they are old carbon film resistors, and when you start messing with old carbon film resistors they start changing values. Especially when you start hitting them with heat. Had I taken the out of tolerance devices off, their neighbors would have immediately changed values. This is due to a lot of factors - outgassing of moisture absorbed in the part over the years, potential cracking of the film, and/or other defects that show up after 70+ years and some heat. If you’re taking these off, take them all off. Sure, it means building new parts out of multiple components, but you then have everything back under 1% where it belongs.
There wasn’t much left in the EICO 249, and I decided to finish it up all last night. This session saw the AC and the meter connected, the two switches wired together, and a few more components laid in. I saw that I missed a wire, so that was put in as well, and the unit generally tidied up.
I tried to keep a layout that would allow you to get inside the chassis without too much fuss.
I did do a check on wiring and a quick operational test, that was a success. Before I call this one good, I need to replace the grease on the switches and coat the metal with contact cleaner to keep it all happy. Stay tuned, a quick test is next, then the wrapup.
