i relize this is old video but if your still living and on here and see this this has got to be the best video of DMM mod and explanatory every what you want to call it awsome job sir.
Thank you :) I actually just bought this meter, now I know how to mess with it :). Liking your style and thoroughness, glad I found your channel. Subscribed.
Great job! As usual your ability in circuit design shines through. The stupid thing is that Uni-T SHOULD have designed this meter this way from the get go. I think MOST people would pay the extra $10-20 for the parts to have a truly well rounded meter.
I know you don't give recommendations. However, what about first meter for personal home automation / checking car relays / Arduino Raspberry Pi type projects? I've never bought one. Or used one. I won't touch the electricity lines (220v here).
The Arduino Raspberry Pi, 100TW death ray, or the ARP flash an LED? I would have no way of knowing, but you do. I started with nothing more than a RadioShack analog meter. I used that meter for several years before buying my first digital meter. For automotive, low voltage work, I have been using sub $50 meters. If the free meters from HF had a backlight, I would just replace the leads and use it. Normally these cheap meters fail due to mechanical problems. Switches, LCDs, cracked cases. You could get something much nicer and have it for many years. It's really up to you. Maybe start learning how they are used before you buy one. Make a list of the features you think you need. Sort out how much you want to spend. How long you expect to own the meter. Then see whats out there that fits.
@@joesmith-je3tq This is great advice! Thank you so much. I really appreciate it :) I'll watch the video now, even if I've watched it before. Respect and best wishes from Pakistan.
The original fuses are labelled BS1362. If you look at the standard from BSi You will find that BS1362 refers to fuses that are fitted in UK BS1363 13A electrical plugs (all our plugs are fused as we use ring circuits for outlets). BS1362 specifically mentions 2 ratings. 3A and 13A. 5A fuses were made, however although they were made to a similar specification, they are not technically to BS1362.
Hello Joe! (the text of this commentary has been translated into English using Google’s online translator, since I speak only Russian and German. I apologize if the translation seems incorrect to you))). You have done a great and necessary job, testing multimeters, I think that any company producing measuring instruments could be proud of such an employee! I enjoy watching your videos, although not everything is clear because of the language barrier. My question will be about UT61E. Yes, yes, I know how you feel about this manufacturer and especially the UT61 line))) But still .. From your videos, I realized that you modified your copy of UT61E, after which its reliability and safety increased. Unfortunately, I did not understand all the subtleties, since spoken English I understand even worse than written speech. I would very much like the text version, on the main points of modification of the specified device, with diagrams and explanations. Maybe you published such an option on some resource?
I just bought a Tenma from Farnell, which I found to be re-branded UNI-Ts (I'm based in Romania, bought if off the UK site) and of course, out of sheere curiosity, when trying to put the battery in, I unscrewed one screw too many and disassembled it. The PCB looks like a mixture between the European version at the beginning of your video and the one you modded. The MOVs were there, the bigger fuses were there, the PTCs were green, I think, but covered in heat-shrink tube, and the protection electronics like your unit. Anyway, great meter for low voltages! Very good value. Pair it with a pair of nice testers and it gets the job done with flying colors.
@@joesmith-je3tq I'll take a closer look. I'll try to take a picture and post it here somehow. I do remember the PCB was marked 61E NEW CE in the lower left corner and it seemed to be dated jully 2015.. but I may be wrong here.
@@carpandrei7493 Thanks. The GS mark would be on the front side of the meter. The EEVBLOG has a fairly large thread dedicated to this meter which includes several pictures. If you have something unique, I am sure many people on that forum would appreciate you posting your pictures there. Just use the search engine for UT61E to find the thread.
@@joesmith-je3tq Hello! Just checked, there is nothing on the front of the meter. But then again, being a rebranded item, it follows most likely Tenma's naming rules. I'll register to the Eevblog forum and post my pictures there, then add a link here. I also bought the Tenma version of UT120B and UT61D. The UT120B is basically identical to the one reviewed by Dave Jones , the UT61D equivalent is scheduled for disassembly today.
@@joesmith-je3tq So, I posted some pictures here: www.eevblog.com/forum/testgear/uni-t-139e-or-61e/msg2721578/#msg2721578 Let me know how it looks like for you. Also let me know if you'd like some more pictures on specific areas of the PCB.
You did the job of an expert consultant for free. You should offer them your services for money, just showing this video should be enough to convince them hopefully.
InXLsisDeo I have found that Joe is quite modest in his level of skill. I believe he could design a meter that would be quite amazing after watching him re-design some of the ones he has fried with ease.
got a new one from AliExpress today, looks the same as your except the 7mmx5mm "c8c*" capacitor next to the big metal can did not have any small capacitor in parallel like yours. the certificate says 18jan2017. The Q6, Q5 are the same as well as the m7 diodes and PTCs. pcb silkscreen print the same as wel. .
This is the video that i been looking for, nice and fair! Just a question may i know what is the actual rating of the ptc and movs that you put in your meter? And also the exact reistor in series and the tvs diode that you replaced in Q1 and Q8? If its ok for some reference for educational purpose only?
This is not a channel for kids to find circuits to try and copy. If you want an education, get a degree. I would NEVER suggest that anyone modify a safety device for any reason. There are many good meters on the market today. Just buy the product that meets your needs.
With all respect sir. Just a question and may be if its ok? I am just asking for the movs and ptc ratings that you replace from your meter, it would be helpfull to anyone like me trying to make this dmm more robust like yours? But in anyway thanks for the reply even if you dont reveal the ratings of the movs and ptc, may be you have a valid reason for that. Thanks.👍🙏
@@rotemon4025 You should NEVER attempt to make ANY changes to a safety device. My goal in making this video was to show the basic steps in solving a problem like this (ESD sensitivity). This video isn't for beginners to use to try and copy paste. Beginners will not have the skills, education, equipment, background needed. It's the internet, filled with 5 minute wiki experts. To be clear, while this meter may survive my basic tests, it does not mean it is any more safe. I would suggest the opposite. This is why the meter is clearly marked and will be destroyed in the future.
Joe - as an expert which meter do you advise UT61E or UT139C? Actually I need TRMS meter around 100$ and I can't decide which one is correct for me. So I need your advice.
I don't typically give recommendations because I really have no idea what anyone's needs are besides my own. If you feel a UNI-T would work for you, I would download the manuals and read them before you buy and watch what ever reviews you can find. On the plus side the two meters you mention are fairly inexpensive so it's not the end of the world if they don't work out.
UT139C was working flawlesly around four years mainly Cat 3 and Cat 2 circutes... Then it was given away as a donation in perfect condition. Second was purchased and it is doing well. If you need a clamp meter to use with this one you can buy any generic one and it becomes a truly universal meter
Good day, what about a transistor clamp arrangement before the main IC pin (like Q1/Q8), instead of the 1 M resistor. Could it work or are they not fast enough when clamping?
I fried my meter. Even with these modifications it could not withstand the high voltages from me stupidity probing primary side of a ignition coil. It is the first notch, AC voltage measurement that is not functioning, all the rest of the functions, even DC works perfectly. My guess is that the $20 (plus a flat $10 handling fee thanks to the customs) main controller has something in its silicon broken, or what else could make it work in DC but not AC? They both have the same input protection. Could it be the C42,C41 caps? joe smith, do you have any answers?
Sorry to hear that. Recently someone on EEVBLOG repaired a UT61E that had the controller damaged. So you may be able to obtain parts for it. You could also try contacting UNI-T to see if they will service it.
Excellent video, could be used as guide to action!!! Is it possible to implement benefits of schematics of flukes 101,107 passed HV sourge test in for ex. uni-t 181 without total reconstruction? Or for (j) ex. in dt-8xx multimeter series (gives a chance to become youtube multimeter god just shooted one video!))) )
Great work sir. I had the ut61e+ until I got a brymen. What's your opinion of the new ut61e+? It has somewhat better input protection than the vanilla old ut61e. I plan to get another brymen but I'm interested in playing with the 61 plus. I've always wanted to put a proper 10 amp fuse. I removed the stock ones and put a few small sibas in it. I'm a software guy from way back but I'm a hobbyist. The difference between the eevblog bm786 and the UT is unreal. One last question. Are all UL tested/csa stamped meters put through all these tests for transients? Once again. You know your stuff and these long form reviews and mods are great. Why you don't have 10x more subs is beyond me when you have people like Paul at learnelectronics with like 150k subs (who falsely claim to be engineers and cant design a pcb to light an led without wasting pcbways time 3 times to get it right) and reccomend every meter that crosses their desk for the clicks. I just picked him at random as an example. Claims to be a psu engineer yet fails time and again at guitar tube amp kit builds and has to get the local music store tech to fix it. When I didn't know anything I looked up to alot of people as gods and ended up reading text books and taking notes more because learning properly is alot more fun haha. I always regretted not taking electronic engineering instead of software in university haha. Sorry for rambling. Great videos.
I made a review for the UT61E+ if you are interested. The meter was damaged early on and I repaired it with non-OEM parts so I would be careful about what conclusions you draw from it. Brymen in general are a different class of meter than UNI-T. For your second question, I would say no. "All" means that no products are marked incorrectly (intentional or otherwise) and that the test houses actually run the tests and don't rubber stamp them (intentional or otherwise).
If fuses are upgraded to Siba 500ma 1000v and other without any other mods for electonic use only (220v current max) would this work? Would it stay in in calibration specs or would those fuses throw calibration specs out of norm? Thank you in advance.
If you asking if it would make the meter safer, I have no idea. If you are asking if it would make the meter more robust, I doubt it. The fuse is not normally included in the measurement, so the only thing effected would be the burden voltage.
A fuse will not do anything for a sub ns static discharge. It can protect you as well as the meter in some cases. No, it does not have anything to do with the calibration, but can effect the burden voltage.
sir , This is very educative .U speak about four light green colour round component that is u say asmass near ptc at 1.57 minute time what is that item and how it works thank u
That's simple, figure out what you need a meter for, then order a meter that meets those needs. If you need it to be certified for safety, just order one that has been. NEVER attempt to modify a handheld meter!!
Got 2x ut61e & 2x ut61a; I did add ZOV 10D471K to those "SG" designation as per new (correct) circuit diagram of ut61e (they supposedly ZOV 7D751K, but 10mm fit quite ok). I haven't done those series resistor by cutting the trace though; probably I will when I blow those clamping transistors one day. Fuses were still their chinese version, haven't ugrade it yet to "GS" designated fuse holder. I think ut61a does with just 2 MOVs, I add the same 10D471K; but they have a large resistor in series near those ptc, probably to absorb those high voltage. Why modify it? As per your suggestion, it's not for safety, instead I suppose it's for the survival of the meter. I'd never use it for high power mains, that's the job for my flukes.
Those ZOV 10D471K were very cheap and uni-t (especially new version of ut61e) already have those in schematic and pcb design, they just chose not to put them in eventhough the price difference would be very small; Now to think about it they probably did it in the idea of "less" robustness, more meter you blow then more they sell it, you just need to keep it balanced between "goodness" and "price" of of the meter against their "cons" (as long as nobody gets killed). Ut61 series were being sold as well under brand name like Tenma and GW Instek.
I would hope that most viewers understood that adding the MOVs would at best provided youngsters with a sense of false accomplishment. I assume by you promoting someone do this, you are well educated on the subject and have ran tests proving that adding these parts has indeed made your meter more robust. I would like to see this data.
Hi great video ! I'm having a problem of frequency measurement of a value around 25 Mhz. This multimeter shows a value of 0 even though it is specified that it can go up to 40 Mhz in the datasheet can anyone help ?
@@joesmith-je3tq I honestly don't know. I'm reading the value correctly from a QUATZ with an oscilloscope but when I try with the UT61E it doesn't work. I'm thinking the problem could be the probes or some unsatisfied conditions
@@yassinedridi3800 I do not know what you are trying to measure but at 40MHz, it's not going to be the same as looking at 60Hz. Are you using the leads that were supplied with the meter? Have you looked at the signal with a scope?
The UT61's were some of the worst meters I tested. Pretty much every meter outperformed them. Keep in mind that if there is any question at what level a particular meter survived to, there is always the spreadsheet that is available on-line.
@@joesmith-je3tq agh right somehow I missed that. Salvaged from another meter. Hmmh... I just gotta figure out where those types of connectors are coming from then. I doubt they're off the shelf part...
@@Mtaalas I would just stay with the meter the way you bought it. I have modified mine a fair amount for educational purposes. There are several videos about it. This was the last showing the lower burden voltage: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-14eHpHQxm54.html
Джо,а почему вы использовали два последовательных резистора 500к вместо одного 1М?Чтобы повысить рабочее напряжение последовательной цепи с 200 до 400 вольт?
@@user-mi8so5fj1v It is possible that I did not have a 1M on-hand, or I wanted to give it a better chance to survive the ESD event. Possibly both. It's also possible that mechanically to fit the parts, I used it to get a longer length. As the video mentions, the goal is not to give the kids something they would cut and paste. It is more just going over some of the basic steps involved. The mods I show are for educational purposes only. I would never suggest anyone modify any safety related product.
@@joesmith-je3tq спасибо за ответ Джо.Я использую этот мультиметр только в низковольтных цепях,в своём хобби,просто хотел немного его улучшить в плане защиты.Вам огромное спасибо за полезную информацию.
@@user-mi8so5fj1v Rather than wasting time, most likely causing more harm than good to your tools, I suggest buy tools that meet your needs. The meter shown in this video is clearly marked so if it somehow ended up in someone else's hands, they would know not to ever use it. My plan is to destroy all of the meters I modified to avoid this potential scenario.
Last night just buy one from e-bay for 40$. According many YT review this is best for bang DMM. I work with electric on work but my first love and hobby is electronic. I know that from pack this is not good for electric work but what you think will survive sometime use on electric up to 440V AC max 2 phase , transformers, distribution box, industrial machine supply etc. ? Like because of big capacity measurement, range measurement, Hz measurement, high Ohm range, 20 000 count. I know that is not have best respond time (refresh rate) but for that money and is very precision , think that is good deal. I have decision between Fluke 117 and this UT61E but just can't see what Fluke give me for that money except that if I made cardinal mistake it will survive. I don't make big mistake maybe sometime that left DC V range when measuring AC voltage :D .
I really don't know how "best" would be defined. We get the 830s for free with purchase here and they normally work out of the box. So for basically nothing, you can get a handheld meter. If you are an electrician as you state, I am not sure why you are asking me. If you felt the GS 61E CAT III 300V is what you needed to work on a 440 distribution over the 117 CAT III 600V, that's really up to you and your training. If you are working in this environment without proper training, that may be a problem and the fact you are asking at all does make me wonder if this is the case. Safety first.
You say that UT61E can't pass CAT 600V ? But on manual is something different written. "This Meter complies with the standards IEC61010: in pollution degree 2, overvoltage category (CAT. III 1000V, CAT. IV 600V) and double insulation."
I did not buy the meter nor am I the one who did their research on it. I can tell you that the last I knew, when I made this video, the GS UT61E was only certified to CAT III 300V. They where marked on the front, CAT II 600V CAT III 300V. The cost for the GS version was fairly high. It seems like maybe double. $40 for the standard one including would be a decent deal. I would expect $80 or more for the GS certified version.
So TLDR out of this 75 min. video, what modifications were actually made and kept to make this pass your tests? I tried skipping around and there was a lot of tried this, tried that, considered this etc. Also out of all this, I didn't get why adding a TVS directly in parallel with each MOV (instead of elsewhere in the meter) wouldn't be a good thing.
John Francis Doe I’d say that it possibly wouldn’t be good for only one reason: it wouldn’t work. Absent good models or good intuition, you have to measure it to confirm that you’re not fantasizing about what will happen. It’s very easy to do that without measurements. I’d say it’s good that all the mods weren’t in one spot: if you’re not patient enough to understand this stuff, you’re probably not qualified to do any mods without there being a good chance that they’ll make things worse. Even the probing technique used here is worth another hour-long lecture. It’s very easy to get complete utter gibberish out of an oscilloscope in such measurements if they aren’t done correctly.
Excellent video, could be used as guide to action!!! Is it possible to implement benefits of schematics of flukes 101,107 passed HV sourge test in for ex. uni-t 181 without total reconstruction? Or for (j) ex. in dt-8xx multimeter series (gives a chance to become youtube multimeter god just shooted one video!))) )
Not sure what you are asking. I have modified both the UT181A and UT61E to pass my tests. Again, the changes I show may make the meters more robust but who knows how safe it would be. My advice is NEVER make changes to ANY handheld meter. That would be right there with the people jumping out their HRC fuses with wire. If you need a safe, robust meter just buy one.
+joe smith Off course it is correct to by robust enough meter from beginning for most hobbyists or specialists. But what to do people which already bought this ut61e, ut71d, or 5 $ pile of...what's sales a milliards of copies? Of course, before buying people watching videos, there someone saying "o it so precise, fast reacting, good resolution, price/quality balanced" but no one speak about robustness and risk of electric shock. That is why my opinion for people already bought this device modification is only way out! And you just proved it in you video. Once again, it is only for people how knows how to hold soldering iron, and understand some electronics bases. And of course this mods is not for latest usage in high current circuits as power distribution units. That's why I suggested to look at device schematics like fluke 101, 107, which passed hv test. Board logic, smd components used and so on could be implemented in another more chip but enough precise meter.
No matter the cost or brand, I would suggest people who have purchased a hand held meter that did not meet their requirements to buy one that does. Compounding one bad choice with yet another VERY bad choice may seem like a "way out" to you but I see it at just being stupid. Right up there with the people who jump out HRC fuses. Again, none of the meters that I use for these tests are something I would ever using on a high voltage, high energy application. I would never sell or even give them away. They are destroyed when I am done with them and then recycled.
