EEVblog

Teardown Tuesday.
3 classic analog multimeters:
Metrawatt Unigor A43: www.haw-hamburg.de/fileadmin/u...
Triplett 630NA: www.triplett.com/wp-content/up...
Simpson 260 XLP www.simpson260.com/260-6/simps...
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[@sp1kage]

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.

[@martinjcamp]

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.

[@ThePostApocalypticInventor]

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

[@md.mostafakhan4529]

I don't know why nobody replied to you. Here I do. :)

[@warplanner8852]

You should get a life, mate.

[@ABaumstumpf]

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.

[@tubical71]

As just to say, the link for the Unigor A43 in that .pdf you can see it´s from a german college...;)

[@CarGuy2024]

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

[@lupojacobo9892]

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

[@ramueller11]

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.

[@enysuntra1347]

Austrian, to be precise. BBC Goerz was in Vienna. I did think it was a Hartmann & Braun-knockoff; H&B Elima also was bought by ABB (Ex-BBC). My father† used a Multavi 5 from the 1940/50s all his life. I just got a "new", 1985+ Multavi 5, and do own a collection of Elavi, Multavi, Wattavis. As a part of BBC, it seems that form factor just was kind of standard in the 1970s-1980s. It WAS expensive with a price in Germany of DM550,- in 1975.

[@snaprollinpitts]

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

[@TheBarry1m]

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.

[@hannonm]

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.

[@Dexerinos]

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

[@fabimre]

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.

[@bryandrap123]

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.

[@peterlaurancearmenio5545]

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

[@elliott1787]

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.

[@pierQRzt180]

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

[@TheBrokeHam]

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

[@macguionbajo]

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

[@AubreyKeck]

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

[@davipoyastro8413]

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

[@Djay0Epizode]

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

[@TechTins_Projects]

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

[@bjornbrandstedt5306]

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.

[@christophers6034]

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

[@youtubasoarus]

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

[@tubical71]

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...:)

[@TradieTrev]

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.

[@TradieTrev]

***** for formalities what you said totally reflects (pun intended) the needle ;)

[@EdEditz]

I've even noticed it on some early digital meters. The display just goes crazy if you rub it with a woollen cloth. :-)

[@bain5872]

***** You're correct. The static charge effects the needle not the coil. Sometimes this charge is very hard to get ride of however, a dryer sheet works every time.

[@TradieTrev]

***** That's fine mate, I like to think of youtube as a unbiased video educational tool. If no-one would correct me, I'd never learn a thing ;)

[@s0nnyburnett]

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

[@cwr56]

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.

[@commodork]

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

[@athf226]

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.

[@UberAlphaSirus]

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

[@whitcwa]

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.

[@richardgoebel226]

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.

[@thebreretons]

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

[@AccessControlForum]

THANKS Dave! Thumbs up!

[@radial9202]

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

[@barrybogart5436]

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.

[@stevecoatesdotnet]

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

[@famossfla]

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.

[@laharl2k]

some guy suggested 10 3v lithium cells as a replacement, in case you havent seen the comment.

[@FrankenPC]

Nice review. That Triplett is beautiful.

[@johncunningham5435]

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.

[@warywolfen]

John Cunningham Mine had the exact same problem, except the battery holder was beyond repair. I couldn't find one locally that would fit, and wasn't going to buy one by mail without knowing its exact dimensions. So I simply soldered the wires directly to the battery, and fixed it in place with hot-melt glue.

[@johncunningham5435]

Thanks Clyde, it's nice to know we can be enervated when it comes to repairing equipment of this caliber, certainly worth the effort and time, especially when you consider what it can do.

[@robertliskey420]

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!

[@pojcharapoltosukowong]

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.

[@sbreheny]

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?

[@JustinAlexanderBell]

That triplett is amazing.

[@ianc4901]

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

[@LPFthings]

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!

[@MisterTalkingMachine]

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.

[@JacGoudsmit]

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! :-)

[@zwz.zdenek]

I agree, he was needlessly harsh on the Unigor. It had, as the only specimen, a very large gap of the contacts of the disconnected relay.

[@supermario315]

We are using them at school today

[@atraxr603]

Unigor is far older than the other two.

[@DjResR]

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.

[@urkkan]

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

[@Stromis_Hobbythek]

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.

[@tubical71]

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

[@jonskunator]

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.

[@Jeepjones85]

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

[@benheatherman2839]

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.

[@andiyladdie3188]

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

[@timonsku]

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

[@robertcalkjr.8325]

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

[@mikeduino4596]

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!

[@dhpbear2]

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).

[@nascar20970]

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.

[@I967]

w2aew did a video on Simpson 260s. Not a teardown, but a comprehensive overview of the series: kzbin.info/www/bejne/m4m0faRqjZlqns0

[@dell177]

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.

[@alextrofimov7947]

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

[@martinda7446]

Александр Трофимов Go look at an AVO!

[@oralcockett9632]

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.

[@DesN4IN]

Love it, got the Simpson somewhere in my junk.

[@schorse1000]

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.

[@ArlenMoulton2]

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

[@sjcwoor]

That odd resistor in the Triplett looked like it had a wood core :)

[@LaughingManRa]

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

[@Gunbudder]

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

[@tubical71]

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...:)

[@frostfirei]

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

[@turboslag]

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!

[@frederickcwinterburn1837]

Now you should take apart an AVO Mk8 and see what real quality looks like. Thanks for the video.

[@electronicsNmore]

Those are some big, bulky multimeters.

[@yoramstein]

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.

[@karsonbranham3900]

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!

[@ronb6182]

I have a Simpson multimeter I want to restore. It uses two different types of batteries. I think I need to replace some resistors. Otherwise I think I will have a working meter. Paid about 15 to 25 dollars for it at a thrift store in north Georgia.

[@Kodachi123]

I've never seen such a construction before; cool! 18:52

[@BloodyCactus]

wut? only 240p here? damn youtube

[@uwezimmermann5427]

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...

[@dell177]

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.

[@PhilippMaierTelevision]

I still have my analog multimeter from the days when i was 15-16 years old. Still works fine ;-)

[@adamWalker555]

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

[@gglovato]

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

[@gglovato]

at 15:29 you actually show D5 on the "bottom" board it has a blue package, can you check that part number?

[@EEVblog]

Ah, ok, thanks, makes sense then.

[@gglovato]

EEVblog video anotation clarification time? :D

[@moses1202]

I love the last one

[@whitcwa]

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.

[@JimGriffOne]

06:09 - Oh god, it takes ages to get this effect off my studio equipment meters. Even putting my hand on the meters doesn't reset them. So frustrating!

[@1959Berre]

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.

[@michaelhawthorne8696]

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.

[@regscriven]

Pity no avo8 thanks Dave good review

[@dhpbear2]

9:35 - Could this be from a time BEFORE zener diodes?

[@tomperli4513]

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 😂😢.

[@joseantoniotovar8996]

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 .

[@CT1ELP]

Hello ! I think analog multimeters are good for some applications specially when you need to read a maximum or minimum point without worry about the specific value itself. Do you think it is worth buying one of those old good ones or a cheap recent (like the Pro's Kit MT-2017) will do the job ? Since you get your hands in so many equipment I would like very much to know your opinion. Thanks.

[@cemx86]

Were those clamping diodes (at 10:30) replaced from germanium to silicon?

[@Kennynva]

Just got a Simpson 270 Series 2 meter..I like it alot..

[@hypurban]

Why do most (modern) multimeters require you to disassemble them to change the battery?

[@AleksyGrabovski]

How does the Metrawatt's multimeter measure capacitance? I thought one need a timer to measure charging/discharging time, and I haven't seen any of these. What's another way of measuring it was implemented there?