I think it's a great video and no it's not dry, it's just not for the faint-hearted. a very good demonstration that a meter's input protection design is not just throwing some PTCs and MOVs to the input, it's way more work to put in and a lot of different testings and analyses to get things right.
Thanks for sharing your knowledge Joe! =) I did a search for "gadget review videos" and RUclips gave alot of asian results, but the search buried the channel until I hit enter. Seems like RUclips is burying fun tech channels deeper and deeper. They have already scrubbed their search. Just a heads-up. Keep making these wonderful videos.
Glad you are enjoying them. If I were trying to use the channel to turn a profit, I would change the entire format of the channel with a different theme, targeted audience and demographics. I really don't care about such things and this is why there are no ads, I don't ask people to subscribe and I certainly don't solicit donations. It's a dry, data driven channel, for the few people interested in following along. I am not at all surprised that it wouldn't show up in the search engine.
Enjoying your channel, great video's Joe! You obviously enjoy your work. Just to tidy up a few details that I didn't get from the video's ...what components did you end up in the meter that you tested? -> PTCs changed to ? -> MOVs changed to ? -> TVS diodes used to replace the transistors ? Maybe UNI-T should sit up and pay more attention to the changes you made! Looking forward to the next video!
Glad you are enjoying them. I ended up with the larger PTCs I mentioned in the video. If you swap them, I would try to find something in the resistance range with a larger body. I think the MOVs I used were from Panasonic. Those may be a little over kill. I think the transistors would work fine if you limit the current through them. I left the resistors at what ever I mentioned in the video. Really, the ones limiting the current to the input pin could be a little lower. I just don't know how far I could push it. 10X smaller may be a good tradeoff. The current limit may be a bit on the small side as well. My goal with this video was not to give a step by step how to modify one. You get people posting about how adding MOVs will make is a better meter somehow. The video was only to show that there is a lot more to consider. Again, I would never suggest anyone attempt this as the meter may indeed be less safe. The same with video where I added the temperature compensation to the UT61E. They are good educational demonstrations but not something I would do to a meter I planned on using.
Thanks for these 2 videos Joe, I changed my plug contacts to brass when I bought it, made big improvement. I don't use mine for much more than 270v AC. I've got resistance test boxes and capacitance test plates plus voltage reference and the meter is very close or spot on. I had a very expensive Snap-On meter I bought back in 1992 cost $850 AUD back then and it died a few years ago unrepairable. Not happy Jan as the saying goes!!!!!!!! Have bee very happy with this although I made my own leads from heavy gauge and thick silicon leads with modified scope leads, they have proven to be very accurate and dropped the short resistance down to nearly zero. Keep the great work and thanks again for the extra effort in this set on the UT-61E.
Hi Joe can't remember who made it don't think I could find any clue outside or inside as to manufacturer. It had been sitting for quite a few years as I had stopped as a mechanic was then a machinery sales manager. When I went to use it I put a battery in as I'd taken it out and when it started up was very erratic nothing measured correctly And even scoping it I couldn't find the source of the problem it would come and go. If you squeezed it sometimes it worked sometimes it didn't. There were no problems with solder joints but I reflowed them anyway, no luck. I spent about 2 days trying to repair it and no luck. It came with plug lead adapter and K thermocouple both lead and probe style. It was the top of the line back then, I also had problems with a Snap-On timing light. Water under the bridge now but I'm happy with the 61E. I also have several analogue meters the best is a KAMODEN TRCX that was owned by a retired flight engineer here, had hardly been used and he'd moved to Spain. I had several others not TRCX and I took one apart and used the rear hairspring from one to correct the TRCX meter. Boy that was fun , NOT.
This meter not worth the time?! It wasn't before you started, but this two videos where great fun, it's really interesting to learn exactly why it failed and the way you modified it is a great step toward how they should have done things in the first place :). Hope to see more of these reverse+forward engineering videos.
I wouldn't be confident in the safety of that uni-t at any point before or after modification, if the goal really was to simply get a more robust meter buying one would be a cheaper option than going through what you did (given you'd probably trash one or two meters in the process of testing modifications) :P. The point is it is an interesting and fun journey to watch, and it shows what some of the differences could be between a cheap meter like this and a decent one in a deeper sense than just "more protection stuff".
I agree about the safety. I would not trust ANY meter that was not certified for the environment I was using it in. Sure they will cost more and people complain about their higher costs and lower features. While I did damage two UT61s before making this video, no other meters were damaged during the testing. My concern when I made the video was I saw a lot of unfounded comments about adding MOVs to this meter. No one had any data on what the end result would be.
These two last videos were excellent, congratulations. I think would be very interesting put the changes in a schematic and share. In addition, a video about clamping circuits like the arrangements with bjt would be useful.
Dave Jones (EEVBLOG) made a video on multimeter input protection. I have made a few as well where I show them in operation. Here are a couple of them.ruclips.net/video/wYCGnYglRjYh/видео.htmlttps://ruclips.net/video/f99Ra1O_u7s/видео.html
Hello. Thank you for taking the time to test thoroughly and even make videos of your work. I would like to perform these changes on a UT61E as well. If possible, could you provide a list of the part numbers (or just specs) used for these modifications ?
Hello, Thanks for answering. After re-watching all of your UT61E videos 4-5 more times each, going through the EEVBlog UT61E thread and other documents as well, i've decided that it's more important to learn the properties of each individual component first (thanks to your "Improving the temperature stability" video), and how they interact with other components when placed in certain way a circuit. There are too many questions for which i do not have answers, and i don't want to just follow some instructions, even though that is what is asked for initially. About the FAQ - I've read it now, the answer is very fair. If i may bother you with another question - What would be, in your opinion, the most correct way to attain a solid knowledge of the basics of electronics ? Thank you.
@@mexykanu I would say it depends on YOU! Your long term goal could be anything from becoming an EE and make a living from it or to just playing around as a hobby. People learn in different ways. Again, you would know what works best for you. The one thing that doesn't work is to do nothing.
Right now the goal is to practice electronics as a hobby while understanding what is going on in a particular project. I don't consider it playing around, since i'm interested in learning all or most of the intricacies of electronics. I'm halfway through the first Volume of the series Lessons in Electric Circuits by Tony R. Kuphaldt (www.allaboutcircuits.com/textbook), which seems to be a good starting point. The question should have been: Would you be able to suggest other resources to complement the above mentioned series of books? Anything goes. Thank you for your time.
Joe would you consider doing a tutorial on your high voltage pulse generator? Not sure if they are DIY but in case they are, I'd love to have some info on it. Excellent video by the way. Thanks.
Joe: Perhaps you'll test the new 61e+? Interesting to discover how the changes will compare to the mod's you made and new performance. Also, I would like to know if the meter will work with the D07-a BT unit. I would like to use it if I could get the Labview VI you developed.
If you look at the spreadsheet, I suspect you will find I have ran more UNI-T brand products than any other and they always do very poor in these tests. Not to discourage you from buy one. If it meets your requirements, get one. Due to the effort involved in running them, I would rather look at products that I suspect would have a chance of doing well.
Also, for the BLE adapter, I checked the manual and there was no mention of it. The only thing I saw what they mention BLE on their website for this series. You would need to write them. I doubt they follow a standard protocol, so if by chance they do support it, you may have to write custom software to support it. It may be more trouble than it is worth.
Hello again, First, thanks for clear and detailed investigations I can learn from. I suggested revisiting the UT61E's plus as it appears Unitrend studied your investigation. I'd enjoy your grade of the quality of their "note taking" and implementation. The D07A is being listed as 61E+ accessory at unitrend store, but not documented. Also, the app has not been updated in 5 years, so I'm not biting. I'm getting the 61E+ because of its features, but my old, old Fluke 75 (one fuse) will still have a place at my meager workbench. Best regards.
@@jspencerg Doing a quick search on YT, it appears EEVBLOG made a review for this meter a month ago. He suggests people ask any questions they may have and he could look into it. You could write him if there's something you would like to see that wasn't covered.
If you would take the time to read the FAQ, I don't offer recommendations. In the case of this meter, you should understand what it's weaknesses and if they are acceptable to you.
I just can't get enough of that 22000 display. 3 decimals up to 22 V combined with quite good accuracy is something I don't see on any other meter in this price range. Of course these features are not exactly usefull to electricians working with more deadly numbers.
I suspect you are right about most electricians not needing the level of features you will find in some of the more advanced handhelds. I also doubt you would find many actual electricians using this brand of meter. That Gossen is a 300,000 count meter (if it were only stable enough to utilize it).
What is the bad thing with having a high voltage capacitor on the input to reduce ESD? The fact that they are high voltage capacitors and dangerous when they fail?
well imagine you are measuring a high voltage node then disconnect the leads and somehow the "input capacitor" stays charged up and you accidentally touched the probes or try to measure a sensitive point on a circuit, you may dance a little bit, or maybe your circuit will.
Hey, I guess it's Scott proof now. Anyone interested in seeing the one meter that failed this test can watch the original video: ruclips.net/video/yJ4s-0czoSs/видео.html Like Joe, I'm not suggesting you try this on your meters. I did this out of curiosity and boredom. The meters I did this to had no value to me and I could afford to loose them. I also wanted to satisfy other peoples curiosity and show them it could damage their meter before other tried it.
Maybe the reason this DMM is so cheap is that it failed the ESD testing and they decided to just ship it as a budget alternative instead of trying to fix the issue.
I think it's a great video and no it's not dry, it's just not for the faint-hearted.
a very good demonstration that a meter's input protection design is not just throwing some PTCs and MOVs to the input, it's way more work to put in and a lot of different testings and analyses to get things right.
I see a lot of posts from beginners suggesting adding various parts to their handhelds. I guess it makes them feel better....
@@joesmith-je3tq LOL yeah, it's like rope walking with a safety rope around your waist, but it doesn't connect anywhere. #My_Happy_Self
Thanks for sharing your knowledge Joe! =)
I did a search for "gadget review videos" and RUclips gave alot of asian results, but the search buried the channel until I hit enter.
Seems like RUclips is burying fun tech channels deeper and deeper.
They have already scrubbed their search.
Just a heads-up.
Keep making these wonderful videos.
Glad you are enjoying them. If I were trying to use the channel to turn a profit, I would change the entire format of the channel with a different theme, targeted audience and demographics. I really don't care about such things and this is why there are no ads, I don't ask people to subscribe and I certainly don't solicit donations. It's a dry, data driven channel, for the few people interested in following along. I am not at all surprised that it wouldn't show up in the search engine.
That is awesome 😎 - i would have thought it would have let the sample out of the PCB after all that!
Enjoying your channel, great video's Joe! You obviously enjoy your work. Just to tidy up a few details that I didn't get from the video's ...what components did you end up in the meter that you tested?
-> PTCs changed to ?
-> MOVs changed to ?
-> TVS diodes used to replace the transistors ?
Maybe UNI-T should sit up and pay more attention to the changes you made!
Looking forward to the next video!
Glad you are enjoying them. I ended up with the larger PTCs I mentioned in the video. If you swap them, I would try to find something in the resistance range with a larger body. I think the MOVs I used were from Panasonic. Those may be a little over kill. I think the transistors would work fine if you limit the current through them. I left the resistors at what ever I mentioned in the video. Really, the ones limiting the current to the input pin could be a little lower. I just don't know how far I could push it. 10X smaller may be a good tradeoff. The current limit may be a bit on the small side as well. My goal with this video was not to give a step by step how to modify one. You get people posting about how adding MOVs will make is a better meter somehow. The video was only to show that there is a lot more to consider. Again, I would never suggest anyone attempt this as the meter may indeed be less safe. The same with video where I added the temperature compensation to the UT61E. They are good educational demonstrations but not something I would do to a meter I planned on using.
Thanks for these 2 videos Joe, I changed my plug contacts to brass when I bought it, made big improvement. I don't use mine for much more than 270v AC. I've got resistance test boxes and capacitance test plates plus voltage reference and the meter is very close or spot on.
I had a very expensive Snap-On meter I bought back in 1992 cost $850 AUD back then and it died a few years ago unrepairable. Not happy Jan as the saying goes!!!!!!!! Have bee very happy with this although I made my own leads from heavy gauge and thick silicon leads with modified scope leads, they have proven to be very accurate and dropped the short resistance down to nearly zero.
Keep the great work and thanks again for the extra effort in this set on the UT-61E.
Was your Snap-On made by Summit? How did it get damaged?
Hi Joe can't remember who made it don't think I could find any clue outside or inside as to manufacturer.
It had been sitting for quite a few years as I had stopped as a mechanic was then a machinery sales manager.
When I went to use it I put a battery in as I'd taken it out and when it started up was very erratic nothing measured correctly
And even scoping it I couldn't find the source of the problem it would come and go. If you squeezed it sometimes it worked sometimes it didn't.
There were no problems with solder joints but I reflowed them anyway, no luck. I spent about 2 days trying to repair it and no luck.
It came with plug lead adapter and K thermocouple both lead and probe style. It was the top of the line back then, I also had problems with a Snap-On timing light. Water under the bridge now but I'm happy with the 61E. I also have several analogue meters the best is a KAMODEN TRCX
that was owned by a retired flight engineer here, had hardly been used and he'd moved to Spain. I had several others not TRCX and I took one apart and used the rear hairspring from one to correct the TRCX meter. Boy that was fun , NOT.
This meter not worth the time?! It wasn't before you started, but this two videos where great fun, it's really interesting to learn exactly why it failed and the way you modified it is a great step toward how they should have done things in the first place :). Hope to see more of these reverse+forward engineering videos.
Right, I would never recommend someone attempt to modify any meter. More than likely the meter would be less safe than it originally was.
I wouldn't be confident in the safety of that uni-t at any point before or after modification, if the goal really was to simply get a more robust meter buying one would be a cheaper option than going through what you did (given you'd probably trash one or two meters in the process of testing modifications) :P. The point is it is an interesting and fun journey to watch, and it shows what some of the differences could be between a cheap meter like this and a decent one in a deeper sense than just "more protection stuff".
I agree about the safety. I would not trust ANY meter that was not certified for the environment I was using it in. Sure they will cost more and people complain about their higher costs and lower features. While I did damage two UT61s before making this video, no other meters were damaged during the testing. My concern when I made the video was I saw a lot of unfounded comments about adding MOVs to this meter. No one had any data on what the end result would be.
These two last videos were excellent, congratulations.
I think would be very interesting put the changes in a schematic and share. In addition, a video about clamping circuits like the arrangements with bjt would be useful.
Dave Jones (EEVBLOG) made a video on multimeter input protection. I have made a few as well where I show them in operation. Here are a couple of them.ruclips.net/video/wYCGnYglRjYh/видео.htmlttps://ruclips.net/video/f99Ra1O_u7s/видео.html
Here is Dave's video as well: ruclips.net/video/zUhnGp5vh60/видео.html
Hello. Thank you for taking the time to test thoroughly and even make videos of your work. I would like to perform these changes on a UT61E as well. If possible, could you provide a list of the part numbers (or just specs) used for these modifications ?
Start by reading the FAQ.
Hello, Thanks for answering.
After re-watching all of your UT61E videos 4-5 more times each, going through the EEVBlog UT61E thread and other documents as well, i've decided that it's more important to learn the properties of each individual component first (thanks to your "Improving the temperature stability" video), and how they interact with other components when placed in certain way a circuit. There are too many questions for which i do not have answers, and i don't want to just follow some instructions, even though that is what is asked for initially.
About the FAQ - I've read it now, the answer is very fair.
If i may bother you with another question - What would be, in your opinion, the most correct way to attain a solid knowledge of the basics of electronics ?
Thank you.
@@mexykanu I would say it depends on YOU! Your long term goal could be anything from becoming an EE and make a living from it or to just playing around as a hobby. People learn in different ways. Again, you would know what works best for you. The one thing that doesn't work is to do nothing.
Right now the goal is to practice electronics as a hobby while understanding what is going on in a particular project. I don't consider it playing around, since i'm interested in learning all or most of the intricacies of electronics. I'm halfway through the first Volume of the series Lessons in Electric Circuits by Tony R. Kuphaldt (www.allaboutcircuits.com/textbook), which seems to be a good starting point.
The question should have been: Would you be able to suggest other resources to complement the above mentioned series of books? Anything goes.
Thank you for your time.
Well I am a few years late to this party but dammit that is awesome.
Thanks for information
Bloody hell, you need to design for uni-t lol :-D
The have the issue they do because they are built down to a price. Not technical ability of the Engineers.
so nice video! i will add MOV in my UT61E.
Joe would you consider doing a tutorial on your high voltage pulse generator? Not sure if they are DIY but in case they are, I'd love to have some info on it. Excellent video by the way. Thanks.
Bruno, if you go to my main RUclips page, select the Playlist button. Look for the Programmable Transient Generator. All the videos are there.
Man...you are great! :)
Glad you enjoyed the video.
Joe: Perhaps you'll test the new 61e+? Interesting to discover how the changes will compare to the mod's you made and new performance. Also, I would like to know if the meter will work with the D07-a BT unit. I would like to use it if I could get the Labview VI you developed.
If you look at the spreadsheet, I suspect you will find I have ran more UNI-T brand products than any other and they always do very poor in these tests. Not to discourage you from buy one. If it meets your requirements, get one. Due to the effort involved in running them, I would rather look at products that I suspect would have a chance of doing well.
Also, for the BLE adapter, I checked the manual and there was no mention of it. The only thing I saw what they mention BLE on their website for this series. You would need to write them. I doubt they follow a standard protocol, so if by chance they do support it, you may have to write custom software to support it. It may be more trouble than it is worth.
Hello again,
First, thanks for clear and detailed investigations I can learn from.
I suggested revisiting the UT61E's plus as it appears Unitrend studied your investigation. I'd enjoy your grade of the quality of their "note taking" and implementation.
The D07A is being listed as 61E+ accessory at unitrend store, but not documented. Also, the app has not been updated in 5 years, so I'm not biting.
I'm getting the 61E+ because of its features, but my old, old Fluke 75 (one fuse) will still have a place at my meager workbench.
Best regards.
@@jspencerg Doing a quick search on YT, it appears EEVBLOG made a review for this meter a month ago. He suggests people ask any questions they may have and he could look into it. You could write him if there's something you would like to see that wasn't covered.
Would you still recommend this meter (unmodified) for low voltage
If you would take the time to read the FAQ, I don't offer recommendations. In the case of this meter, you should understand what it's weaknesses and if they are acceptable to you.
In my opinion this meter is a perfect benchqueen.
LOL. I was thinking my Gossen would fill that roll.
I just can't get enough of that 22000 display. 3 decimals up to 22 V combined with quite good accuracy is something I don't see on any other meter in this price range. Of course these features are not exactly usefull to electricians working with more deadly numbers.
I suspect you are right about most electricians not needing the level of features you will find in some of the more advanced handhelds. I also doubt you would find many actual electricians using this brand of meter. That Gossen is a 300,000 count meter (if it were only stable enough to utilize it).
Haha love the outro!
well done ma, Welldone! A+++++++++++++++++ more videos please. your bro from dubai
What is the bad thing with having a high voltage capacitor on the input to reduce ESD? The fact that they are high voltage capacitors and dangerous when they fail?
Low impedance path for higher frequencies. Not sure from a safety standpoint what would be required.
well imagine you are measuring a high voltage node then disconnect the leads and somehow the "input capacitor" stays charged up and you accidentally touched the probes or try to measure a sensitive point on a circuit, you may dance a little bit, or maybe your circuit will.
Hey, I guess it's Scott proof now.
Anyone interested in seeing the one meter that failed this test can watch the original video:
ruclips.net/video/yJ4s-0czoSs/видео.html
Like Joe, I'm not suggesting you try this on your meters. I did this out of curiosity and boredom. The meters I did this to had no value to me and I could afford to loose them. I also wanted to satisfy other peoples curiosity and show them it could damage their meter before other tried it.
LOL!! Yes, this is the new Scott standard of excellance! I would guess the stock UT61E would not survive if you creap up on it.
Maybe the reason this DMM is so cheap is that it failed the ESD testing and they decided to just ship it as a budget alternative instead of trying to fix the issue.
Many of the UNI-T products I have looked at fail this test including the UT181A. They are not certified to meet the EMC standards.