Nixie multimeter repair (M1T-242)
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- Опубликовано: 25 авг 2023
- Fixing an old bench multimeter M1T 242 with a nixie tube display and autorange function. It measures AC and DC voltages, currents and resistances in 4 ranges. It was made in Czechoslovakia in 1987 by Metra Blansko, mostly using Tesla components.
The online calculator:
ohmslaw.eu
The 2nd multimeter:
• Fixing what somebody e...
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Thanks for that last comment. People have to hear that more these days.
"Makes more sense than the hyperloop I guess" never a truer word spoken great vid. Oh yeah please have a look at the other one...cheers!
8:13 This over voltage protection is actually used by Fluke since many many years, there is an EEVBlog episode that explains it: #1157 - Transistor Zener Clamp Circuit
thanks :) I didn't know this was commonly used.
Thank you for bringing me insight in this era of technology I was not a part of.
Awesome, definitely try to fix the other one too.👍👍
Thanks 👍I'm working on the other one ;)
@@DiodeGoneWild Awesome 😎
Great video. Definitely try to fix the other one. I learn so much from your interesting videos.
That meter is beautiful inside!
Personally I like watching the fixes because they reveal the failure mode of the device. So I think you should definitely fix the other one. It would be interesting to see what broke or failed in it.
I would like to see that too.
Wow, the update rate is really fast. Faster than modern multimeters and all done with discrete logic/transistors. Only the $300+ stupidly expensive keithly/keysight multimeters are that fast.
Yes, I also like the fast update :). It's very practical when trying to set a potentiometer looking at the display.
As soon as software processing gets involved, things get mushy.
When thinking about the old times we get melancholic because of how WE were, not because of how the THINGS were...
Interesting that they still used nixie tubes in late 80s. I am quite sure that time there have been 7 segment LED displays in eastern europe too
Yes, LED displays already existed (red, yellow, green), but they were dim. Tesla in Czechoslovakia was producing some, East German RFT also produced them. But a lot of devices still used nixies for a better readability. There's also M1T-242A version, which used green LED displays unlike my M1T-242, otherwise mostly the same thing.
I love these older analog devices
Where I live these types of devices are extremely rare
Yes you should definitely try fixing the other one!
Marcoreps would be proud
he would have changed all caps just for good measure.
@@stanimir4197yes i think he would, instead using modern one's, he's gonna use new old stock ones like Soviet or TESLA caps
Great vintage technology, Nixie tubes are awesome, and these have the nice 5's. Interesting that they were still used for displays in the 1980's. Tesla makes a lot of electronic components and discrete TTL drivers with 7490, 7475 and 74141 IC's for the tubes.
Why not keep using nixies, if it works :). The LED displays of that era were dim. USSR kept producing nixies (and even dekatrons!!!) until 1992.
100% agreed there.@@DiodeGoneWild
Would be fun to go over how its ADC does the measurement
I love the little clicking sounds it makes while ranging when you disconnect the wire from it!
Just wanted to hit you up and thank you again for being you!! I've been trying to teach myself Electrical Engineering for a bit now, and because of you and your cat, I was able to fix my first SMPS!!! You put out a video about 4 years ago using the same control chip. so,,, LONG story short, because of the way you explain electronics, ( i think your cat is a bit better but::)) Thank you so much!!
you are AMAZING!!!
Nice electronic build quality. Made in the time when quality and durability were a concern to the manufacturers. Looks old, but if it works, then great.
Nixies will forever be my favorite display technology.
Nixies were always very cool
Indeed, freedom of speech is a right to be fought for.
Yes, go for the next one! Nice job!
I've started working on it ;)
@@DiodeGoneWild Niiiice ;-)
I always find your channel very informative, educational and very entertaining, especially when the Cat chimes in with a comment.
I have been in Electronics for 55 plus years now, I used to service Arcade gambling machines in an arcade on the coast here in England.
Qualified Radio Amateur. Now playing with LiFePo batteries and inverters.
Built and fixed many computers in the Desktop days, not so much now with portable devices, the components are way too small to see.
I have been practicing with SMD components but struggle to see without a huge magnifying glass.
Keep up the good work exposing all these dodgy and super dodgy chargers.
David (G1ZQC) U.K.
Devices with a transformer and diode power supply can actually cause quite a lot of interferance, usually the diode conducts only a small fraction of the cycle, you get current spikes that start a moment before the AC voltage reaches it's peak and stop at the peak voltage, without any inductors the peak current through the diode can be in the range of 10x the load current and it get's worse with more filtration, short current pulses cause a lot of harmonics and result in EMI
Tak toto video ma veľmi potešilo! Sám vlastním dva takéto kúsky, obidva kúpené na bazoši, jeden funkčný, druhý nefunkčný, ale nebudem sa pokúšať ho opraviť keď jeden funguje, lebo opravy mi idú veľmi zle a ani neviem kde by som mal začať. Inak je to veľmi pekne vyzerajúci prístroj, ja osobne považujem digitróny za najkrajšie displeje a hneď po nich sú fluorescenčné displeje v mojom rebríčku obľúbenosti. A na to, že tam nie sú žiadne LSI IO (obvody vysokej integrácie) ale iba SSI a MSI (malej a strednej integrácie) tak ho dokázali vyrobiť veľmi malý a kompaktný. Tento prístroj sa myslím si že Metre Blansko veľmi podaril, najmä vzhľadom k tomu, čo bolo u nás dostupné (myslím súčiastková základňa).
I recently got two Czechoslovakian solder guns too, it works so nice and it actually can run long before overheating :)
Ia it a tesla soldering station or those big bakelite soldering guns?
@@petermikus2363 they are both soldering guns
That is a VERY awesome meter!
I love your cat's comments! She's awesome. :)
Your channel is the best!
Impressive in general too see how basic electronics used to be. Thanks for the upload
I've had Meratronik V543 in my lab. Was quite heavy, but also very accurate due to dual slope operation. I used it quite a lot till it died in very unpleasant way back in 2013 (tantalum cap failed on short and burned PCB traces)
Pozdravy z Polska!
I have V541 which still works to this day :)
Those 7475 latches explain the meaning of that Connels' song:
I was the one who let you know
I was your "sorry ever after"
'74-'75
Giving me more and I'll defy
'Cause you're really only after
'74-'75
That's pretty neat man... I dig it.
Thanks
Thank you for your support ;)
Vyborne, dekuju.
Nice one man.
Beautiful!
Good
Nice! Would love to see the other one repaired too.
Good stuff, very wise words at the end! 😎👍
Those tiny range relays clicking is like electronic ASMR to me.
I absolutely adore older tech like this, and I also love nixie tubes. I have a nixie clock actually, and you should definitely try to repair that other one.
I also like the sound :) well, I like the sound of big relays and contactors too :D. Old technology is simply way cooler. I've already repaired the other one, the video is now available for my Patrons, it will be public on Sunday.
"It makes much more sense than the hyper loop I guess" 🤣
Nice repair :-)
Great bro
I love these old tech repair videos DGW, definitely have a go at the secong unit, or at least put it on your "to do" list
Yes, let’s see you fix the second one.
Yes, fix the 2nd one too... always good. I can see at some point that +/-15V module blew and someone replaced it with a 7815/7915 selfmade module.
Nice! I want to build one like this. ;)
Nice fix, and yes definitely fix the other one as well! :)
How I fixed the other one will be shown in the next video ;).
Another top video, nice cat comment.
Even I recognise the Metra Blansko logo, and I am Australian.
How that's possible? :)
@@DiodeGoneWild When I was a little kid, I obtained (from somewhere, I don't know where) a polystyrene box of 10uA panel meters, and each of them had a Metra Blansko tag tied to it. I think it was because the USSR was sending a lot of stuff our way in its latter years.
There were enough of them that I still have some, and so many of my projects have the meters with the "Devil's Tail" M logo conspicuously shown.
Very Good!!
Wow what a wonder multimeter, the tried and tested old tech has many advantages including well defined MTBF data and its easier to repair/maintain than bleeding edge tech...
Nice.
Thanks for bring your cat back. Number 1 1Apple Macbook repair hater and ranter has a new armchair and his 3 cats must suffer in silence.
I love the looks of eastern European electronics! You don't find cool stuff like this in the U.S. Anything with nixies is cool anyway, which is getting harder to find although there is a company in Czechoslovakia that is now producing new production nixie tubes. They are NOT cheap, but rightfully so. Thanks for sharing this excellent technology with us!
Is there a table or calculator anywhere that says what ESRs are "acceptable" for what capacitors?
Thats a nice bench meter, i'm sure you will make it accurate and stable :-D
If it was mine i would swap the displays/drivers for led ones, but that's my bias.
Exploding filters lol , fun for all the family 😀
I didn't expect the capacitors to be that good still.
Replacing nixies with LED displays? Noooo! Hell NO!!!
And electrolytic capacitors are not the worst problem, paper capacitors are. That's why I replaced the interference filter preventively. Fortunately, no other capacitor in this thing is paper.
i have done this once, but the frequency counter belonged to a friend and the nixie tubes were really really dead.
all the voltages were there, but the tubes were very dead.
i replaced the bcd chips for led drivers and resistors.
I terminated the high voltage supply.
The led display was green, i still have the old chips.
@@zx8401ztv I'd rather give it new nixies ;) because this is like straightening the Leaning Tower of Pisa :D.
@@DiodeGoneWild Well there were experts that carefully improved the foundation and made it tilt back a little.
Its safer than it was :-D
I think it was built on Crappy soil (How the hell did it not fall over).
All of the Nixies were very dead in that frequency counter,.
The owner was so happy that it worked again.
I found nothing wrong with the supplies.
The ovan was perfect. But it would not cook my dinner :)
I still have the 12 driver chips (20 years ago) (why i dont know)
SN74141 4-10 line BCD to DEC None latching 60v numerator Output.
Yes, T3 en T4 make more sense than that other thing.
Ty dva antiparalelní tranzistory jsou ochrana před pěpětím přesně jak jsi řekl, využívá se tam zaverneho napeti asi 5V na prechodu B-E. 🙂
Are we still living with our ancestors 😂
I don't think the construction looks that old, especially for a professional type tool which does not need to be flashy and modern. I was just working on a Sony Walkman also from 1987 and was surprised it was all through-hole components.
I noticed the smoke marks on the power strip. Was the cause shown in a video we have not yet seen?
Make an autopsy of the filter that likes to explode.
12:42 About this ring tester, how does it work and what can the information be used for?
He has two videos about it.
ruclips.net/video/QBbEYYWiBI8/видео.html
ruclips.net/video/E1dopmxph2A/видео.html
Just out of curiosity: Does the meter switch make before brake when changing the current ranges ?
They probably didn't have a 63mA fuse. It is a pretty tiny value.
Is the clicking at 14:29 the relays?
yes, the reed relays ;)
Completely unrelated to the video content, but you have a variation of the Schuko 16A mains connector used across most of the EU; when did the Czech republic adopt this connector? I assume it was post 1990?
Our type E socket is better! :) it looks nicer, it's polarized (unlike type F), and the ground has a more reliable contact.
@@DiodeGoneWild But in Fance and Belgium, the phase must be on the right hole, exactly opposite to the czech standard. So it's only polarized in a single country. The Schuko also has a very reliable ground contact and can handle continuously 16 A like live and neutral without overheating. It doesnt look nicer to me because Im used to Schuko and the older ungrounded sockets. In my unpopular opinion, the british plugs and sockets are absolutely the worst ever invented: large, ugly, heavy and overengineered safety designed to protect dumb people from shocking themselves.
My dear, how many years old this digital mullti tester?🤔
fix the other one!
What about that two red LEDs? 🤔
Strangely, they're not in the schematic :). It seems to be a slightly different version. They're using them in a series combination instead of the DZ1 Zener diode. It's in the current source for the resistance meter, I guess.
mám v práci na stole obě verze, i tu s LED displejem. Mají jednu výhodu, nepotřebují baterky :)
@1:06 minute......😀😀😀😀
Imagine it's price in 1968
Nájs.
8:12. Ah, so someone else wasted their time reading the white paper as well ;).
This over voltage protection is actually used by Fluke since many many years, there is an EEVBlog episode that explains it: #1157 - Transistor Zener Clamp Circuit
Co vím tak tam lidi dost často mění i ty tantaly.
nice post komunist multimeter , 87 , ehhhh nostalgic , but my dear frend , must to very deep renowation this , elektrolitic caps , all , second work new kalibration or clening all licensed isotats ,
this multimeter first stage bulding its a very godly ic op amps , TESLA low noise maa 501 or maa 701 or letter models , typical analogic construction
You should try some Polish electronic equipment from communism era.
máš české věci tak mluv česky
Freedom of speech is really not a thing in the Europeans countries (except maybe to a certain degree in some of the Scandinavian countries) - only the things you are not allowed to say or you have changed. You will still be jailed if you say the wrong things.
Freedom of speech is a very important thing. As is freedom of the press (media) and free and fair democratic elections to decide on the government.
@@Mark1024MAK It is desirable - but not a thing in Europe (with few limited exceptions). Freedom of the press - exists formally, but of course the press is also covered by the speech crime laws.
Can you gift me one of them please?