What's inside a vintage analog multimeter (AVOMET)

[@johnsmith7676]

In the United States, a company called Simpson used to make very nice meters quite similar to that, also with bakelite housings. They were very well built. I still have one that was my father's, and it still works well. That Avomet unit is beautifully constructed, I must say. Very interesting. Thank you.

[@neail5466]

More vintage items please .... please. I am surprised how much experience you have for example, you understood and explained the nonlinear feature of that AC scales which we newer gen people's may overlook. I like your this nature of delving deep, I also recall the reverse turning and of screws for plastic moulds, those tiny details made you my favourite. I wish you prosperity, thank you for being with us. When I watched your first video about laser you made me laughed my guts out, from then I eagerly wait for your videos and completed your whole playlist. And your accent, unique, light and makes serious matters lucid, Can't forget your Cat,🐈too.

[@Conservator.]

Beautiful vintage instrument. I love these devices.

[@1pcfred]

Yeah I have a thing for old analog meters myself. He did a great job restoring some ranges on it.

[@DiodeGoneWild]

I plan to fully restore it, another Avomet is on its way to me, I will make one nice one from two crappy ones. There's a lot of them on the internet, nobody wants those analog things those days...

[@1pcfred]

@@DiodeGoneWild it is a beautiful instrument. A lot of work went into making it. There's things an analog meter is still best suited for. I was trying to measure the current of the spindle on my CNC machine and none of my digital meters could. But my old analog meter averaged it out and gave me a reading. I'm not sure if it was right, but it was something. Was a Chinese SMPS running it. So very dodgy.

[@keithking1985]

I hope you do restore it!!! I look forward to that video😁

[@1pcfred]

That's a beautiful old meter. A shame it has the issues it does. Try dissolving the glue with acetone. My guess is that it is some kind of a cyanoacrylate Super Glue. Has that crystalline look to it to me.

[@Killerspieler0815]

@Paul Frederick - YES , highly likely cyanoacrylate based Super Glue ... hope the plastic lasts longer than the glue.

[@1pcfred]

@@Killerspieler0815 I don't think acetone hurts Bakelite. No harm in trying now anyways.

[@bradysolaem2467]

Acetone ftw nail polish remover for the poor yet savy

[@1pcfred]

@@bradysolaem2467 I buy acetone at big box stores in gallon jugs. It is one of my favorite solvents. I use it for degreasing prior to painting. Acetone is pretty cheap. I think the stripper stuff is stronger than nail polish remover too. When you buy acetone all you get is acetone.

[@DrHouse-zs9eb]

Very interesting. Never have seen such resistors like in that vintage device...

[@NickNorton]

Previous owner: Oh, I'll just add a spot of Super Glue. (tips bottle over multimeter) 😞

[@uzaiyaro]

As a pure guess, the positive being common might be for positive earth things, like old cars after the war. It’s said that positive earth uses slightly less copper, and there wasn’t much of it, so they went with that. They were also all over the 12v game really early on because you needed less copper to run the same loads. It could also be that it’s treating things ‘scientifically’ since electrons move from negative to positive (I think? The atomic scale is something I know nothing about.) Just some silly ideas from someone who loves weird old 50s British cars.

[@SigEpBlue]

Man, I LOVE meters like this. A solid Bakelite case, embedded solid-brass contacts with 'copper finger' moving contacts, hefty wire shunts, mirrored-scale analog meter with actual GLASS over it...and that's actually amazing that the case is still with it, intact, and in pretty great condition inside. That was a real damn shame about that 'glued' knob, though. The 'cylinder' in the movement is to increase the inductance of the coil, making it more efficient, i.e. greater deflection with less current. My compliments for removing the moving coil and getting it to work again, though! I can't tell you how many movements I've done 'surgery' on over the years, but it's a real skill, and I've received MANY instruments for free, just because the movement needed a little work. That said, iron vane movements are now my favorite. LoL BTW, the term you're looking for is "parallax error," when you describe using the mirror to get the right viewing angle of the needle on the scale. :)

[@DiodeGoneWild]

I'm about to upload a second video about it ;).

[@LutzSchafer]

The rectifier is a copper oxide one. They where common back in the days

[@tinkmarshino]

This was very interesting... I enjoy looking at the old meters.. they are so amazing to me I have a few of my old ones around and one or two that my father used in his day.. Thanks for a great video.. carry on..

[@Conservator.]

4:54 When you measured the resistance of the current meter, the switch was on the voltage setting. Could that be the cause of the very high value you measured?

[@DiodeGoneWild]

Maybe, if the voltage/current switch disconnects the shunt. Or maybe the shunt was blown. It was set to the lowest current range, so the shunt gets blown very easily :).

[@tuxrandom]

Probably. I think the current path a good multimeter should be open circuit when not measuring Amps for safety reasons.

[@paulfontaine7819]

Imagine the amount of work that went into making this. It must have been very expensive to buy.

[@FaysalKhalashi]

Ahhhhh... I was waiting a long time for nimh charger video from diodedonewold...

[@TechGorilla1987]

@6:00 - Here in the US, we call that material *Bakelite*. Excellent stuff that isn't really used any more. **Edit - It still has limited uses and is still in production in various forms.

[@DiodeGoneWild]

We also call it "bakelit", but I wasn't sure if this word was international :). I think that the entire housing is bakelite, not just the thin cover.

[@TechGorilla1987]

@@DiodeGoneWild I agree that the entire device is Bakelite. Unfortunately, it's also a brittle material especially with the passage of time and application of UV rays.

[@1pcfred]

@@DiodeGoneWild Bakelite was invented close to where I grew up. Three towns away. It's weird stuff. When it is made it is actually baked. Well the mold is heated up under pressure.

[@1pcfred]

Bakelite is still used in electrical applications. Bakelite is resistant to heat, and a lot of solvents so it has desirable properties. Bakelite is a phenolic plastic. So Micarta is basically Bakelite. Same resin.

[@keithking1985]

Yeah your right it is bakelite,, and it makes perfect sense giving its age that it would be used. Plus it does have great thermal propertys!!! It mad how it was invented to replace pool ball's(which were made from ivory at the time) and win a competition(plus the contract for pool ball's back in the day)

[@dadler9705]

Case material is called bakelite, a very early plastic. Avoid crushing or scratching it because it contains amosite fibers ( a type of asbestos )

[@joebenjaminbrawley]

I hate flat head screws. I always slide off the screws and end up stabbing my hand.

[@tuxrandom]

And I never have the correct size screw driver for them, even though I have like 10 different sizes.

[@yakitoly7461]

RandomTux it’s easier to use different side screwdriver on them than on cross headed screws

[@1959Berre]

A very interesting device presented by the singing technician. :) Now the words "gliue" and "scriuw" are haunting me for the rest of the day. The old glue might have released by heating the parts with a heat gun for a few seconds.

[@jeanjean9343]

Good show, as usual. I'd cut the knob off with a Dremel Tool, that would get you in the case with only the loss of the knob. Ultimately it wouldn't have changed the outcome though, and Hindsight is 20/20. Over the years, I've broken a few things, only to realize that once apart, if I had only pressed here or pried their, it would have come apart successfully without damage. I bought an Analog Multi-Meter on EBay, guaranteed to work, it didn't. The seller refunded and profusely apologized, I'm OK with that. So I bought a modern analog Multi-Meter, LED Display Illumination, Simulated Meter Scale Mirror, it's silver, but you can't see the reflection. Nevertheless, I bought it to show the grandkids an analog meter in use. It works fine overall, and exceedingly fine for demos. There was an Analog Meter made by Radio Shack years ago, Analog Movement driven by Electronics, it would only deflect the correct way, regardless of polarity on DC, but it would set an Indicator Light saying that the polarity is reversed. Wanted to buy one recently, used, but couldn't find one. I do enjoy your shows, keep up the great, and interesting efforts.

[@godfreypoon5148]

This is the perfect tool for when you need to Czech the voltage or current.

[@golfman9290]

The mirror as you say is if looking at an angle ,which is called parallax correction, some old cameras used to have this on the viewfinder, to compensate for difference of the image seen by the finder and lens, the viewfinder being higher than the lens. As always a very interesting vid, cheers.

[@luminescence1646]

1:40 to dont have paralax error. Nice vídeo!

[@jkobain]

They got balls of steel!!

[@denisvlkolacek4597]

We´re using similar in our school. :D

[@yxcvbnmmnbvcxy544]

Using the "Ganzuniv 1" in school in Germany

[@mrnmrn1]

@@yxcvbnmmnbvcxy544 You currently use a Ganzuniv-1 at school? Wow, that's a 40+ years old model analog meter from Hungary *(but they're still selling these brand new for about 300EUR!!!)* commed.addel.hu/30020-analog-multimeter/498019-ganzuniv-1-univerzalis-muszer . Also strange that you use it in Germany, since the Ganzuniv-1 is a knockoff of Goerz Unigor, which is a German multimeter :). So I guess your school is in the territory of East-Germany.

[@electronic7979]

Helpful information video. I like it.👍

[@isidoromaich7226]

🙂

[@Ale.K7]

Beautiful meter, I hope you can fully restore it!

[@DiodeGoneWild]

Of course I will do, I'm about to get one more crappy one and make a fully restored one out of two.

[@Ale.K7]

@@DiodeGoneWild Great! :D

[@westelaudio943]

That thing is probably pre war with those tar caps and bakelite case. Or very early 50s. Probably acetone helps with removing glue residue. Also, there were analog meters with tube or FET amplifiers inside and very high input impedance.

[@noakeswalker]

A nice Bakelite object ! Those brass contact switches look like they came from an industrial motor controller of the time - modern pcb trace switches in multimeters look feeble by comparison :o)

[@bentumbentum]

The plastik can be one of the first who is produced. In germany we call it Bakelit.

[@oniruddhoalam2039]

I think the material is bakelite. Bakelight is an old synthetic plastic which was used for making telephones and electrical goods.

[@grumpybollox7949]

such an interesting video, thanks man

[@zx8401ztv]

I like the way the switches were made, big contacts with multi spring wiper :-D Even if it worked, it would have no use in this day and age of digital accuracy.

[@RubenKelevra]

There are still uses for analog meters, but they are very limited

[@zx8401ztv]

Ruben Kelevra Yes you are right, i have an old Avo 8 multimeter and its ideal for peaking the moving voltage of radio circuits. Analog displays are more compatable with the eye/brain, like having a light that changes brightness with adjustment. I forgot about peaking uses.

[@RubenKelevra]

@@zx8401ztv you can also measure fluctuations with an analog meter. For example if you want to set the stab setting on a avr for a generator a analog meter is much more helpful than a digital one.

[@perolozac01]

The whole case (and much of internals) looks to be made of bakelite which is very heat resistant. Maybe if you carefully heat up the shaft for that knob it would melt the glue and do no damage otherwise?

[@hyperion8008]

Too late now, but some heat may have softened the glue? The case is made from Bakelite which is very brittle but can handle some heat more than plastic.

[@DiodeGoneWild]

Maybe.... or some solvent. But anyway, I have another AVOMET on the way, so I can maybe make one working piece out of two deteriorated ones.

[@TechGorilla1987]

@@DiodeGoneWild Please document this as it would be very interesting. Thank you.

[@1pcfred]

Why is everyone saying Bakelite is so brittle? Bakelite was some pretty tough plastic depending on the blend. Some manufacturers just added too much filler to their mixes which made their plastic weaker. They usually used sawdust because well it was sawdust. Which was cheap crap.

[@Drew-Dastardly]

@Paul Frederick - In all my experience with old stuff, Bakelite was most definitely brittle. It was tough though easy to scratch but when it did take a decent knock it would shatter like an old 78 gramophone record. Or cast iron. It definitely never deformed like a plastic.

[@1pcfred]

@@Drew-Dastardly I guess looking at it that way. But there's times you don't want plastic to bend. A lot of times. Bakelite was knocked off by a lot of manufacturers too. And in the quest for higher profits they used lousy filler materials in their blends. Which made poorer performing products. Not all Bakelite was created equally. I grew up about 10 miles from the original plant where Bakelite was produced. So there was a lot of the good stuff in the area I grew up in. Although I can remember the lousy stuff taking over.

[@milantrcka121]

Four years later... Just finished restoring and calibrating mine. Pushing sub 2% accuracy all ranges. Had issues with movement, broken resistor lead, rust and corrosion.

[@vitcenek8611]

I've got about 8 of these after my grandfather, each is differend. They were made in 30's 40's and 50's in Matra Blansko Těch avometů jsem po dědovi dostal asi 8 a každý jiný :D

[@godfreypoon5148]

I have a big box full of Matra Blansko generic 100uA movements. Been using them in projects for decades now. They're very nice.

[@DigitalBhangari]

You were so patient with that solar charger. This is shocking.

[@ChriFux]

Most glues get weak when you heat them up. You could use that in tue future to separate glued metal parts.

[@publicmail2]

No not really you are thinking of cell phone glue which is a thermal glue.

[@EliteHEAD]

There is a glju in the skrju :)

[@astromancer]

d skrjů is komplítly čůd

[@Pawelr98]

I have a UM3a analog meter from 1970. Similar type of construction. If the rectifier is selenium or copper oxide (the second beeing the case with mine) then trying to replace it with any modern passive equivalent is impossible. Even small-signal Schottky cannot match the copper oxide rectifier at low current. Tried it with mine and Schottky performed marginally better in the higher reading region, however in the lower region it performed worse. It was a nearly 50 year old rectifier with increased series resistance. Brand new it would have had outperformed the schottky at both ranges. The non-linearity of Schottky and copper oxide is different. Modern replacement would require a new scale. What I did is I decreased the series in-circuit resistance which was common for all AC ranges as it was in series with rectifier. AC reading went back to normal on all ranges. For AVOMET it would be R22 that needs attention. I still use my analog meter because I find it better for certain applications. The shunts are much better quality than ones found in chinese made mutlimeters.

[@snaj9989]

I have a vintage analog meter too. The guy that I got it from told me its in working condition but it wasnt. It had lots of blown traces on the board so I soldered new lines for them but its still shows false readings and some functions doesnt work. I would like to send it to you but probably the shipping cost would be insane.

[@pirataga]

I love your videos, Diode, you're the kind of person I wish I could be friends with in real life. You could have used goo gone or a similar product to dissolve the glue, I have one bottle here and it's very efficient to dissolve some kinds of glue

[@richardnanis]

You give lots of care and love to these old vintage devices with questionable use worth :-) I also like these old devices and restaurations but i always ask myself is it worth it?

[@RazvanTataroiu]

15:48 "Let's measure the short-circuit current of a battery, because why not?" :D

[@oldmanhuppiedos]

A beautiful old skool electromagnetic meter, you had to think about that. You can try to gently heat the knob so that the glue becomes fluid again. But the brute force also works. LOL Bakelite and glass are not made for brute force.

[@Miata822]

Beautiful old meter. It's a pity to see it in that abused state.

[@AmitabhAnkur]

Your videos are good

[@meinkamph5327]

Super Awesome! I want it.

[@Userx29]

Hello there, I bought Multavi II, some wires are not connected in its correct places, due to previous modification done by its previous owner, after consulting its original Schematic diagram, I found many round coil resistors (actually 3) in it, and not appears in its diagram!! I could not fix the AC path, any help would be appreciated!!

[@shawnn8692]

Nice old meter! Heat is your friend with adhesives old and new. Or your enemy if you are an adhesive.

[@TazkoHoZabit]

why not use an acetone or another glue dissolver?

[@vidasvv]

Great video, TNX for the upload ! 73 N8AUM

[@-yeme-]

damn shame whoever filled the thing with glue destroyed it basically :( so much quality of materials and workmanship inside, all hand built

[@douro20]

I wonder if it was made under license from Avocet in the UK?

[@DiodeGoneWild]

I'm not sure, I've never heard of Avocet....

[@1pcfred]

@@DiodeGoneWild Avocet is a very famous instrument company in England. It was their Simpson or Triplett. Which are big analog meter manufacturers in the USA. In case you've never heard of them either.

[@bradysolaem2467]

This one is very tight... Bloody hell each one is a different length

[@andrejz.1156]

We still use many of these multimeters in school . Students hate them becouse you need to know how to read of analog value .

[@Passco666]

I have same.. cannot compare with standart digital one this is beast ;)

[@Magneticitist]

Wow those are some old resistors

[@erikziak1249]

The housing seems to be bakelite (or bakelit as you know it). It should handle higher temeperatures better than common thermoplastics. Aha, now I see other comments. No need to write more. :-)

[@-Crash-Nebula--]

the positive. is to excite the base of the transistors. or to use it in microampers

[@vijendrashirodkar9247]

diode gone wild which multimeter u like the most analogue or digital.

[@DiodeGoneWild]

I like analog meters, but the digital ones are more accurate and practical :).

[@nettyvoyager6336]

its made from baker light the earliest form of plastic sort of it was more like asbestos and a compound resin

[@bitterlemonboy]

Bakelite. It's called Bakelite

[@whitehoose]

Fixing my slippery knob always makes me do A vomet ... leaves a nasty taste. My first meter looked very much like this one (1972) except it was called an indicator (we didn't calibrate them in those days) it was a hand me down from an earlier time. The big difference was mine had a flat filed into the shaft to prevent the old spin a ma-thing with the range knob. Within a couple of years of getting my first meter we were using more modern coil meters filled with flimsy little components ... then in very short order the first LCD meter became available - bloody useless article needed new batteries every week and the scale sample rate wasn't damped so readings would swing up and down at dizying speeds with capacitive or dirty lines. When we had a new precision measuring desk, it came in kit form. The tec who assembled it calibrated ranges by either removing wire from the wire wound resistors or on the large shunt resistors he used a hacksaw and file to remove material to increase the resistance. constantly checking temperature and cross referencing it with a table. That soon changed too, now the only thing that's big is the display and the interface that integrates tester with the remote comms link

[@pshq]

DiodeGoneWild, stop stealing interesting electronics from shops! Why aren't they removing the protection otherwise xD

[@tomasvarga9471]

Kde ste sa učili po anglicky?

[@Ultr4d1ck]

Nice vintage avometer.. Seem the construction is so robust compared to cheap 1$ plastic ones... Please restore it to original condition.

[@DiodeGoneWild]

Another dilapidated Avomet is on the horizon. I hope I can make one good out of the two.

[@legomachines5970]

Vintage. I like it

[@enoch7thadam1st2]

that is correct "01:10" because if plus is minus and minus is plus. then it becomes a lot clearer. (',')

[@keithking1985]

P.s what year do you think it was made?????🤔

[@keithking1985]

And it could be a future restoration!! Something to think about!!!!👍 I'm sure a lot more than just me would like to see that😁

[@jusb1066]

Late 40s to late 60s, the British avo was similar looking and constructed at that time, avo stood for amps volts ohms

[@tomasbrod1533]

I hav this AVomet. It mostly works.

[@MathewLiamHowarth]

Do you have a Czech channel?

[@DiodeGoneWild]

Of course I do :)

[@dezeekat]

THEY HAVE BAAAAAALLLLSSS

[@vitcenek8611]

Ta podložka co vypadá jako miska sloužila jako polomba, zakapávala se pečetním voskem a nebo později barvou

[@bradysolaem2467]

Cool!

[@santanunath3224]

Nice

[@grigoreman7198]

I gave you like but you had to not break it. I like old and durable appliances

[@materialnyxl]

It looks similar to Polish UM-3 meter, maybe Czechoslovakia and Poland were cooperating when designing those meters? You can find polish instruction and schematics on: multimetry.tzok.eu/multimetr.php?typ=UM-3_1

[@Jeremy_Moro]

RIP Aviomet multimeter

[@joselaporre5163]

Am sir. I. am sorry. You can use WD-40 right 😅

[@Conservator.]

How come you have the shop protection device on the NiMh charger? 🤣

[@DiodeGoneWild]

They forgot to remove it :). And my sister bought a coat and they left 2 pieces of this protection on it! So I have 3 now.

[@theo3888]

The video is from 18 minutes ago how are you from 8 hours ago

[@Conservator.]

Reverse Gamer Patreons can view the video’s a few hours earlier. You should try it too 😉

[@atmel9077]

Few years ago, I bought clothes and when I came home I realized they forgot to remove it... except it was the one with the ink in it. So I had to return it :(

[@dasibaho]

Danny, it’s not plastic but Bakelite :)

[@paulfontaine7819]

Bakelite was the first plastic made from synthetic components

[@celsoneves2368]

Cool!.

[@ondrejmager]

No, takýto stav som neočakával. Tento prístroj naposledy používal môj strýko za svojich mladých rokov, pravdepodobne :). Dúfal som v lepší stav, ale aspoň som sa niečo o ňom dozvedel. U mňa by len roky ďalej ležal v pivnici.

[@DiodeGoneWild]

Nevadí, moc díky za dar :). Aspoň sem mohl prozkoumat a ukázat, jak funguje ;).

[@Killerspieler0815]

@DiodeGoneWild - maybe its from 1950s ... the repairer did far more harm than good , he/she should have used office tape = it worked fixing my analog microwave´s knob

[@timtim8468]

Nice, especially the box, and the accessible contacts on the bottom, never seen this before. In general about those meters - the better ones got the hand hanged with a wire instead of a bearing. Those are much more sensitive. The hand can be very fragile in those, it will break when touched like in the video, sometimes they are made of glass. I got an old EAW. In very old meters AC is often shifted, maybe because of the semi conductors used. DC only meters sometimes work forever.

[@CW-pu4yb]

Definately from bygone days. All handmade.

[@diyordie7431]

The restoration disasters S01.E01 :)

[@noplastik]

Vyráběly se proudové bočníky, tuším na 60A a ty měly 60mV - přímo zapojitelné do zdířky 60mV. Nebyl to špatný měřák, kupodivu měřil docela slušně AC do desítek kHz (cca 50). Jako ohmmetr dost naprd. Tehdy se nějak předpokládalo, že obsluha ví co dělá (např. že se neměří ampéry v zásuvce), "idiotresist" konstrukce to není :-)

[@erikziak1249]

Ináč parádna retro vecička, chcel by som ju mať, samozrejme plne funkčnú. Predpokladám že pôvodný návod odporúčal merať najprv na najvyššom možnom stupni a postupne znižovať, podľa potreby, až na najnižší, aby ľudia hneď neodpálili merák.

[@davey2k12]

I bet he hit it with hammer now come off 😂😂😂 Was funny at the time , ya at to be there 😆😆😆

[@defook]

7 rokov do zadu sme ho ešte používali v škole na meranie :D aby sme nepokazili digitálny multimeter

[@denisjocsik7745]

bol to môj prvý multimeter aj do dnešného dňa ho mám 😃

[@bradysolaem2467]

Love the accent lol. It doesn't woooork

[@dezeekat]

EVEN MORE GLYUUUU

[@oh_what_a_cool_man]

8:50 noooo

[@keithking1985]

It's a shame you had to destroy it to get it open but we'll worth it. That was really cool inside😊 and just goes to show how far meters have come over the years.. I'd say it was a top of the line meter in its day!🤔... AS Always ya don't disappoint!!👍👌 great video!. or should I say excellent video😁 as usual👍 (I'm going to watch it again right now and put a bookmark on it the in my favorites list) 💎

[@geoffreykeane4072]

Bloody hell! :-)

[@stanislavdimitrov7347]

Made in CZ

[@kampkrieger]

hey clive.... öööhhhhh not clive... okay but similar and good (and weird :D)

[@publicmail2]

Clive only takes apart electronics < $5.

[@kampkrieger]

@@publicmail2 mostly, but sometimes similar and he has old stuff too. Not that old though. I don't mind anybody "copying" his style (desk-cam). That is more tear downs for me. Just surprised by the "wrong" accent after clicking on the thumbnail

[@vladimirmrva599]

Čo tento robí.! Ten nemá ani šajnu čo má v rukách.!

[@Drew-Dastardly]

1kohm per DC volt is very poor, near as useless. That would be what to expect on the AC range. The best meters at the time would be UK manufactured AVO or a USA manufactured Simpson which had 20kohm per volt. They had an Ohms setting (Amps, Volts, Ohms - get it?) and protection including a physical cutout sprung button that had a hair trigger if you measured a higher voltage on the lower range. I would trash this meter and find an AVO or a Simpson to restore.