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The Unigor a43 was manufactured between 1970 and 1975. So a ~40 year old multimeter that is still that accurate is good even if it doesn't look beautiful.

It's great to see someone get so excited about this classic old things. Since all of this stuff was designed and assembled by hand, the amount of craftsmanship and labor in each device tells us all of a much different time in History.

coming home, having a coffee, watching a new EEV-blog episode...It's like my daily sitcom

Unigors are still used in many European universities, and they still work very nicely. I happened to work with one ~2 years ago: Some people asked about how precise they are, and after comparing with some fluke, other brands and 2 oscis there, and if you take the time to read it with a lens and interpolate the values, you can go down to 0.1% error. Oh, and btw, the Unigor A43 gets tested up to 5000 V to make sure, it is 100% to use to 1500 V. Didn't know that it looked that terrible inside, but when looking up different models i saw, that they vary greatly.

Wow, I never realized that people collected multimeters, I was great to hear how excited you are about them and I have to agree, they are beautiful inside.

I have several vintage Triplett 630 variants I still use today, built between 1954 and 1965. You can't beat a quality analog meter. I love the bakelite case and large meter. Outstanding construction unparalleled to this day

Dave, I used this type of Unigor multimeter already in 1965 at school when I was studying Measurement and Control Technics (Electronics and pneumatics)! In those days they did not yet use epoxy circuit boards (to expensive) outside of the military.BTW, I am from the Netherlands.

Good video. There are Simpson 260 models with mirror on the dial. They usually have an M after the 260. Bad thing about the Triplett and Simpson is how brittle the Bakelite is. I have seen scores of cracked cases and faceplates. You're right about the current Triplett meters not being the same quality. Word of caution about the Triplett: remove the batteries when putting it in storage. Too many switches have been destroyed by the leaking batteries. And repairing them well is no easy task.

The Triplett Insides made my jaw drop! thats so vintage and such hardcore design. I am very pleased to see something so old, look so good.

Great video Dave, I can remember using the Triplet 630 in electronics lab back in 1976, great meter. thanks mike

Ehh...I liked the German meter the best. I think there is better attention to detail like the spark gap and the much larger air gap for the spring loaded disconnect. Exterior design, it is the best and I don't really get how it's being knocked for a dual board construction when it seems the other meters are somewhat half-ass arranged in mid air.

Enjoyed the episode...I purchased the equivalent of the Unigor back in 1973 and it was then marketed in the US by Simpson Electric under the the model number "Simpson 257". Mine was manufactured in Austria by Goerz Electro Gmbh. It looks pretty much like your specimen inside with the phenolic type PCBs. The range selector switch is very solid with the ball bearing snap action feel. It is still very accurate and I like the capacitance measuring feature, from about 0.01 to 5.0 microfarads. For those measurements, an external 50-60 Hz 100 to 240 VAC must be applied.

I just have to mention the resolution and Clarity of this video is incredible

You made me purchase a that Triplett and glad I did.....very happy with mine.

The protection diodes on the Triplett are in a single package. It is that brown gold leaded component on the back of the meter movement. The 630-PLK had the overload reset. I have a pair of 630As, great meters, but I'm jealous of the NA's range doubler.

I agree that the Triplett is the clear winner, I own the Triplett model 630NS and like yours is identical in everyway except for the 30 volt battery. This particular model uses a 1.5 volt AA battery to achieve the same readings in the high resistant scale. When I purchased this on EBay it came with a leather case, original test leads and owners manual all in mint condition. The only issue, the battery had leaked so I fabricated and repaired the 1.5 volt container to get the 100K scale working again, well worth the time and effort.

have a Simpson 260 series 6. Great general purpose in its time but now retired. Thanks for the teardown

The Simpson!!! I haven't seen one of those since my first year in college. They wouldn't let us use the digital ones till we could prove we could use and read an analog one, such nostalgia

So nice too see these old techs inside-out :)

EEVblog Dave, the Germanium diodes on the 260 board that you comment on at 20:24, are actually part of the protective relay circuit. This 260-6XLP does not have individual back to back diodes across the movement, but rather a single component that is essentially, 2 back to back diodes in one case. At the 20:15 mark in your video, it's the tan (or green) colored component with gold leads, between the meter terminals, and hidden between the 2 calibration pots. It looks like a resistor, but is printed with the Simpson part number 01-110670. It was a purpose made varistor for meter protection, and can also be found in the Triplett 630 as well, printed with it's generic part number V64. (in your 630, it's the gold leaded tan component at the 26:40 mark) They are no longer available, and current production 260's and 630's just use two back to back 1N4148 or 1N914 diodes in it's place.

This actually turned out to be very entertaining to watch! and the last multimeter... just wow.

The Unigor is proof that outside appearance doesn't mean squat, as it took me a few girlfriends to realize. I have a 630NA and had a 260, but I gave the Simpson away. I am a big fan of Triplett. I have a 310 (of course) and an 850 VTVM - an improvement on the RCA Senior Voltomyst. And I think the 2030-C is THE best pocket DMM.

I have the Triplett meter at my desk, it was my grandfather's before his passing. Also have a Fluke 8060 as well. Both of them still work pretty well despite having quite a... rough and active life of frequent use and abuse.

I'd like to see a comparison between older precision resistors and the ones that are in use today, and the equipment used to calibrate them.

12:00 "I don't know how reliable it is" - talking about a working 40+ years old multimeter.

Hi Dave, I myself have the Unigor A43, but is not from Metrawatt. it is from BBC GOERZ, I love this Multimeter. It is very accurate for an analog, also through the mirror Scale. And the screwable input connectors, are very practical.

Check out the busted diodes 21:15. Does the Simpson meter still work?

I like the triplett, but I do like the simpson line as well. The particular one you featured is not as nice as many that they make. I have a 270-5 which is still manufactured to this day, and it is down to 1% accuracy on a 270 degree taut band suspension. It is a very nice meter. The classic 630 triplett is very , very nice. great video!

I got a Simpson 260 series 3 for a Christmas gift in 1962 and still use it. That Simpson has 5,000 v (ac and dc) jacks on it besides the jacks used for the range switch.. I also have a Unigor from the 60's that I got when the company i worked for in the early 90's shut down, that is a very accurate meter.

At 26:08 it was a trimmer capacitor, not resistor. ;) (Mica Compression Trimmer Capacitor)

In my electronics class in high school we had a about 7 Cen-Tech multimeters and a Simpson and 3 Triplett 630-PL meters I always loved the Triplett meters the most. There was just something about the loud sharp click of the switches and the heavy weight to them that I loved. I remember one of the students had one of the Triplett meters on the 2.5 DC range and probed a output on a 22V DC laptop charger and it pegged the needle so hard it bent the tip of the needle and the damn thing still read accurately (After straightening the needle). Although I still had the same issue with the loose input jacks.

I remember using those Unigor meters in school in the Netherlands in the early 1980s. I remember how those switches felt, they were pretty awesome. But even back then they were already pretty old. I'm not surprised you found Pertinax (FR-2) being used for the circuit boards, that was common in the 1970s. I can tell you don't like it, but I think the relay and all the protection are pretty awesome, and probably perfect for use in schools: that way if a 12-year old kid wasn't paying attention and set the range wrong or something, they wouldn't have to throw away the meter or change the fuses all the time. Beauty! :-)

Thanx for this one Dave!! :) Especially because I got a Unigor A43 here at my bench as well, using it nearly every time, when measuring currents, as needle movements are much more better to see then just numbers on a DVM. Thanx for this Unigor teardown so much, as i do not have to open up my one...:)

"it has the right tongue angle" is that technical term! Love it!

Static charge on analogue meters o.O Well that's something I hadn't noticed before, makes perfect sense because all the display is a coil of wire.

Great video, I appreciate your fondness for the Triplett. I still prefer the Simpson for several reasons. One the 30 volt battery is not cheap to replace. The Simpson uses a standard 9 V and a "D" cell. Second the easy access to the batteries, you can open the Simson battery compartment with a coin. Third the documentation for the Simpson meters is great. I not only was able to repair it, but calibrate it as well with easily obtained documentation. Fourth the Simspon has a 250 mV/50uA scale. One issue with the Simpson, some versions (notably the 7) had a reverse banana plug jacks so it required special leads, while the others had standard banana jacks. I also like the roll case you can get with Simpson. Accuracy for analog meters is not a pressing issue anymore. I use my mainly for peaking or nulling adjustments. If you want accuracy even the fairly cheap DMM's will out perform any analog meter. The mirror for avoiding paralax was on all the "M" versions Simpsons.

What's cool is that Triplett meter is just like the one my Papaw used in the industrial field for probably his whole life. Those meters are the best. You can actually still buy those 30v batteries off amazon for around 15-20 bucks. Great review it really is a thing of beauty lol

Drat, I almost sent you my old AVOmeter 8 last month, could have had some real competition in the line up!

Holy crap, I remember the Triplett in my vo-tech class. That is a bit of a trip down memory lane.

This was great! I have both, and you are right the Triplett range switch has no peers. I also have the vtvm version sane era same quality,, Mil spec tubes even! Keep up the great work thank you!

As for the "cutOuts" @ 04:06 and up, this is not in first place a meter protect, it acts like a circuit protection (when i work with my unigor, i find this very nice and handy) If it´s under voltage or current, you can not overload the meter (readout) as it is active meter drive anyway, but if you turn the selector to its off position under load, it always cuts out. Even while measuring low currents it cuts, so the circuit under test and the meter is always save...:)

Well, my main multimeter is a Analog one. a Sanwa YX-360TRF. It's just a stasifying feeing seeing old school needles moving left and right. Oddly stasifying.

Very impressive resistor gallery on the Triplett 630NA. Interesting layout.

I have a triplett 630-PLK, same design as the 630-NA except for the range doubling switch. The PLK also has a reset button.

I can't watch this today, but I would like to say, I can only just wait to watch it tomorrow.

Dave - that trimmer mounted on the side of the Tripplet's range switch looks like a compression trimmer cap. I've never seen a pot like that. Are you sure it's a pot?

Dave, enjoyed this vid. I just had my 260 xl opened up. The D cell leaked and made a real mess, cleaned it up and reworked a couple solder joints and all is good now. I love these old meters, Recently refurbed a KG 625 VTVM, those are nice, as they give you an analog movement with high input z. Thanks, again!

Simplest solution is the best. Really enjoyed the comparison teardown.

Amusing how we've gone from spark gaps on the input to basically trying to insulate the terminals as much as possible, imagine that spark gap firing while trying to measure a large capacitor!

Great video Dave, as always. I recognise the component at 26:08 as an adjustable mica capacitor ..wonder what it does??

26:08 The so called trimmer resistor looks a lot more like a trimmer capacitor to me. But otherwise good teardown, Those multimeters have definitely better quality than my AVM360.

Hahahaa. The Dave's expression "crusty" always makes my day. It's perfectly descriptive. Like a pizzabox-formfactor 286 PC with yellowed case, which makes a crunch when you open it, and has some corroded metal structures inside, that's some crusty stuff.

If I remember correctly, they call it "OUTPUT" because it can be used to measure the AC component of an audio amplifier stage's output which has DC on it.

Get a Sanwa 380-CE, they are the best made meters I have ever seen.

You need to do a teardown on an Avo 8 Dave!! Probably the most famous multimeter in the world! There must be alot in Oz, in fact there must be alot anywhere in the world, except the USA. It was THE must have meter when I did my electronics training but I wasn't able to afford one then. With the advent of ebay I was finally able to indulge myself, I now have about 20 of the things in different types. Also, the GEC Select Test, a meter introduced to compete with the Avo. You will be shocked when you delve into an Avo though!

The Unigor pcb tracks are silver plated, and over time they tarnish (silver sulphide) and hence look unattractive. The movement is a taut-band suspension and of very high quality. I have an earlier model which is the most precise analogue meter in my collection.

Great video David. I am sure you would like to review the Avometer. This is not very popular in the US but is in my opinion the most elegant e well constructed analog multimeter. It doesn't have the polluted scale panel of the others. The voltage scale is the same for AC and DC. The "1" voltage scale is the same size as the "3" voltage scale. No special scale for low voltage AC. Resistance positions do not jump ranges, i.e., you have X1, x10, x100, x1000, x10000. You certainly will recognize a great engineering efort in this meter. The construction is extremely solid. It also can handle very high voltage. Check it out.

I´ve done a little "Unigor A43 AtWork" followup to this, covering some goodies, and of course some reasons why i really like the Unigor A43 Analog Meter:Unigor A43 AtWork

Oh man, seeing not one, not two, but *three* classic analog multimeters together like that gets me sooooooooooooo hot!

Thanks Dave Another great tear down video. I have the a Triplet 630 and love it. Sad but the 30v battery is near impossible to get anymore.

I love old school electronics, you can smell those antique electrons from here !

Recently I acquired a vintage Hansen SC and a Unigor 1S multimeter. Both instruments are in fine condition and have been sitting on a shelf in a climatized basement for many, many years. The Unigor 1S was build in 1963; its price was 365.00 Deutsche Mark (about $180 US), which was about the average monthly salary in in those days. Unfortunately it needs a rather unusual 1.5V battery, way shorter and more bulky than a modern AAA cell. No idea if that size battery would still be available anywhere in the world.

20:08 - Looks like these 4 diodes make up a full-wave bridge rectifier circuit for the AC ranges The protection diodes appear to be next to the funky plastic-tubed range resistor (21:50).

Your 1 1/2 V "D" cell battery in the Triplett 630 should not be an Alkaline cell. It should be a Carbon Zinc Eveready "D" cell. It all depends on the corrosion damage YOU want, right?

Triplett is great! A pirce of art! :-)

Dave, the two diodes you saw on top i think are the back to back protection for the relay coil, check the schematic(it shows one part of the diodes going to the range switch). you haven't shown D5/6 which are on the movement, those are probably germanium

Try the Metrawatt Unigor 4p .This is my mostly used Analog , beneath the Metrix MX 573 . But the Metrix is not a pure Analog one. In the older days, I also often used the Unigor 6e ( also electronic inside), but unfortunally this Meter gets in Trouble if you have a Cellphone in your pocket 😂😢.

I think Triplett is a winner, very nice build, quality nichicon cap, niceeee!

Fantastic meters, Dave. I have to say I loved that old battery as well, love when they still build charges after decades. I have a few Matsushita/National Panasonic branded AA's I found inside an old Super 8 camera, a couple of them still read about 1.4 V and can drive low power stuff like clocks and joule thiefs.

Love the commitment ^^ EEVblog #634 - Analog Multimeter Teardowns

Excellent informatión and teardowns congratulatións. I have a Simpson 260 is a 50 year old and still working like the first day , my multimeter can measure up to 5Kv. Thank you and have a nice day .

The "crustyness" is not crustyness at all, but just silver showing its age through oxidation. Some instruments use silver tracks for its superior qualities to silver, sadly, silver can tarnish in an ugly way -especially if its in a high sulfide atmosphere

The output connector with the cap is (for example) for measuring the NF voltage at a speaker in a tube radio, so the high DC voltage gets blocked. They made specific output meters back then, but why not integrate it in a multimeter.

Nice ! I have a BBC Goerz Metrawatt MA 4E that i use daily, my digital only gets used when i need that extra precision.

Dave can you find an AVO8, these were the meters I used in college Great video of old stuff, thanks. If you watch Top Gear, they say you should never drive your hero car, i.e. You loved the classic car but on driving it, it kills your nostalgia for it because of the dated tech in the car. I think Dave got this from this tear down specifically from the Unigor.

I dropped that model of Simpson off the wing of an airplane I had been working on. It exploded when it hit the ground. I almost cried. I now own a 260 series 7 and have a Triplett on order.

I think a little tear down series of the Simpson 260 1st gen and all the way up to the new ones would be interesting. I have the 2nd to the 7th gens and the difference is great to check out as they upgraded the technology but kept the same case/look.

My favorite multimeter is a cheap Lafayette Radio Electronics model which has a continuity buzzer.I bought it in the early '70s and still use it. On the Triplett, I would have expected that two diodes would be for meter protection and four be used for AC volts.

They all look great. I'm an AVO fan here, so its cool to see some alternatives :).

I think that the triplet is in the off position and so the meter would be shorted to protect the movement. This will prevent the meter from reacting to the static charge from the cloth, the other two meters are not in the off position. I can't explain the small movement from the triplet in this test though.

Those are some big, bulky multimeters.

The Simpson is a classic for sure, my computer networking teacher back in high school kept one on his desk because it was his first meter he ever got, even had the joy of using it once :-), but I will say that Unigor does look nice on the outside, but inside I was OMG WTF?!? at that horrid construction lol!

I have a couple of Unigors made in trhe 60's, very good meters. The one I use most is my Simpson 260-3 bought in 1963, it's not as accurate as the Unigors but overall it's the best for troubleshooting just about anything.

Just love those Ballbarians! Gotta love Dave's accent.

Dave you forget to mention that first two are transistorized (in order to get higher sensitivity ) while the Triplett is not, what means its moving coil is of better sensitivity.

wut? only 240p here? damn youtube

on the Simpson: is that a ball of solder in front of one of the transistors? Also comparing the distance between the open relais contacts for the Metrawatt and the Simpson I would put more trust into the Metrawatt...

The Unigor is originally from Goerz in Vienna, Austria. This model must be from the early 70s the design probably from the late 60s. We had such devices at school in the 80s and they where pretty historical even then. The inside you showed is rather sure not the original condition the meter was delivered. I have seen the inside of some meters in school and also visited the Goerz production and this was definitely not their production standards then.

I like all 3 of them because there all solid but for quick servicing i would go for the triplett.I have always liked Simpson but after this video would go for the triplett and the German one also would go for as the ranges are higher.

With all the videos Dave has done of battery discharging, I'm surprised he tested that 30V battery open circuit.

the best meter I ever had was issued to me at AT&T. back in the old days they gave you the best tools, later on everything was junk especially the multimeters. It had no brand name on it, just a KS no. meaning it was quality stuff that met phone co. standards.

A little while ago, I bought a 630-NS (that's the 200,000 ohms/volt version!) from Ebay, and I wanted a manual. I downloaded one from the Triplett website. I also perused their current products. I was surprised to find that they still make the 310! My guess is that they are still popular with radio/TV engineers. That's because an analog meter will work OK in a strong RF field, while DMMs sometimes flip out.

On the Unigor, the soldered joints, look to have been resoldered.

That triplett is amazing.

it's 40 years old for Pete's sake. The Unigor A43 was of exceptional quality for it's time. Lets see how accurate a modern Fluke would be after 50 years of use. It won't even work! And there is a lot wrong with that particular point to point arrangement on the Simpson

THANKS Dave! Thumbs up!

Dave, if you don't like the Unigor, please feel free to send it to me :o) I love my Unigor A43, which btw is labelled "BBC", as Metrawatt was part of BBC at a certain time.

Thanks Dave, that was great! I'll vote for the Triplett.

trippy, i was just using the simpson in the lab the other day. we have very very old stuff in there.

AVO Meter 8 Mk V 3kV AC/DC Parallax mirror Polarity reverse switch Microamp DC range Insulation test Re-settable overload A thing of beauty, to coin a certain phrase & Made in England! 😋