EEVBLOG/UEI 121GW Part 3, Voltage, Current AC+DC, Capacitors

It's been over two years since I looked at the 121GW prototype. I wanted to allow Dave and UEI plenty of time to address the problems before reviewing it.
In Part 3, we compare how the 121GW behaves against other DMMs when measuring small capacitors, currents and voltages. We finish this segment running a few higher voltage tests.
Feel free to join the thread:
www.eevblog.com...
cat/?PHPSESSID=nakhi153ramc9d1j055iih4nr3
One of the problems I ran into back in 2017 while looking at the prototype was with the VA mode. Roger, who ran the YT channel KainkaLabs, repeated my tests. He did a really nice job explaining the problem and how to work around it. I doubt I will go over this problem again, so if you're interested, I suggest you watch his video.
• 121GW VA-Mode Problem ...
An old video explaining the transients I apply:
• Programmable Transient...
The data for the meters I have tested may be found here: docs.google.co...
Answers to Frequently Asked Questions may be found here: docs.google.co...

[@ngtflyer]

I experienced much the same erratic behavior with a Klein MM700, which as I understand, is also a UEi meter. Its very slow ranging and super slow settle times are what sent me on a quest for something better. This is how I found your channel in the first place, and ultimately purchased my two Brymens, both of which I am very satisfied with.

[@eddielee9486]

I own and use a Klein CL2300 and it shows the same slowness to range and settle. For capacitance, it also exhibits the same positive offset or zeroing. Both the CL2300 and 121GW generated comparable results... both with settling issues. In resistance the CL2300 takes longer to range to zero from overload. Might be UEI typical standards for time and least significant tolerances. Always figured they were a poor mans Fluke, so lived with it... built with IP & drop ratings, UL listed CAT IV ratings. Btw I was one of the unlucky ones that bought a 121GW fairly recently and got stuck with an older rev PCB. Noticed the silkscreen when I opened it, but figured they didn’t sell well enough to burn through initial stocks. My ignorance was bliss until Joe’s discovery. Still, while not a perfect meter... comparing other $200 US new meters, compares well... and yes I think the Swiss army approach seems gimmicky, but what novel features that has been added for the price (15v diode, low burden, low Z, bte data logging, VA) are functional to a point, when a more appropriate dedicated option for the job isn’t available. I don’t get why so many expect performance of $300-600 US fluke/Agilent/Brymen. Maybe my bar is set just very low, having lived with a Klein for a few years.

[@jamesmauer7398]

Nice video Joe. That is a concerning issue you found with the 121GW not indicating the DC voltage when present with the AC voltage. Hopefully this will be/has been fixed in firmware.

[@MarcoFranceschini1971]

Beautiful collection of DMM Joe...

[@joesmith-je3tq]

It's about a third of what I have looked at. Most were damaged beyond repair and recycled.

[@beznachala]

Как всегда, лайк за видео👍🙂 Благодаря твоим трудам, в прошлом году взял себе Fluke. Дальнейших успехов!

[@sergeymishchenko9596]

Аналогично. Только в этом году, благо скидка была 67% (витринный образец) - 287 вещь!

[@nikmilosevic1696]

Interesting results, another great video!

[@abeleski]

you are full of it! What would you know

[@nikmilosevic1696]

@@abeleski lol

[@wouter_scholten]

You only opened up 1 of the 2 1.21gw meters, right? So perhaps that other one has a different PCB version and the v.01 was one that just 'ended up' in between newer ones. It is interesting that the production date of pcb is week 45 of 2017, prototype week 20 of 2017 so both some 2 years old... As to you suggestions: only 1 company was ever interested in suggestions I made to some products as an outsider, and being a consultant still gives hardly any interest from them in anything you're not hired for, they go the way they want to go unless there is enough outside pressure. So in my experience giving solutions as you did to make it more robust is unlikely to influence them (manufacturer + whatever input dave has) much in itself. And what you mentioned about his reviews, it woukd have been interesting for him to review 'his' 121gw in the same style, his early multimeter reviews are good, critical where they need to be, but in recent years what he puts out is barely interesting, superficial stuff and "let's make more fun of stupid ideas on kickstarter" which results in 30 minute videos of him laughing about something stupid, that could have been more serious and done in 5 minutes.

[@Okurkaarrgghh]

The serial numbers are 11 off, so they are from the same batch.

[@WHS_reviews]

@@Okurkaarrgghh: Well, the PCB numbers are not necessarily similar, even though the device serial numbers are close. An older PCB or an older batch of PCBs may have been unused at the factory then recently used for some reason.. The only way to be sure [ edit: Of what the PCB date it, not what happened at the factory ] is to open it up.

[@Okurkaarrgghh]

@@WHS_reviews You have more chance to win the lottery than that happening to Joe's meters. They both had firmware 1.57; these are both old stock.

[@WHS_reviews]

​@@Okurkaarrgghh: Depends on how old 1.57 is, I don't know what the time difference in dates of that and firmware 2 is. Also what I was getting at is that the factory may be the issue, dave may not know what he gets exactly without manually testing them all, so then the question why he sells 'old stock' could be that he doesn't know... So then it could be that he only has some old meters, the rest are newer and thus what you get is based on luck.

[@joesmith-je3tq]

See attached post: www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg2779204/#msg2779204

[@Daveyk021]

What, not hero worship? LOL I was kind of hero worshiping myself when I ordered my 121GW. I was expecting a meter handed down from God himself. Instead I go a Harbor Freight special (although it's built a lot nicer). It is very good at some functions. For resistance trouble-shooting, it is useless. I still really enjoy Dave's videos and still kind of hero worship him, but his expertise is not taken as lightly, or assumpulously, as I use to.

[@joesmith-je3tq]

Yeah, no. lol.

[@milky3ay566]

Thank you for testing this meter in such highly details. For electronic uses, which one of this meters you highly recommended? My budget rage $100 - $200. I want a meter that last me at least 5 years. Thanks 🙏

[@ahmedalshalchi]

Forget 5 years , think of the moment and how to make benefit and gain. You cannot predict future so don't be insured of your continuous successes...

[@milky3ay566]

Jim Mitchell that’s actually a really good meter to get. I just got a job as a firmware developer and I hate fighting with the multimeter I have currently (cheap one) due to loss banana jack ports and wasted so much time. Mostly I program arm and avr, uA measurement is a must have feature for me. The meter you recommended me seems reasonable, thanks.

[@joesmith-je3tq]

I won't normally recommend meters. That's covered in the FAQ. My favorite meter that anyone could procure is the Brymen BM869s. The other meter I like is that Fluke 189 but these are all very old. I am the third owner of the one a friend of mine had passed along to me. It was shown in this video. Both of these meters have the basic features I want and are both very electrically robust.

[@mtkoslowski]

@ Joe: How do I upgrade the EeVBLOG firmware please? Is this a factory upgrade only? Thanks in advance. 😊

[@joesmith-je3tq]

I would just read the manual and follow the instructions. You will need a way to get the files onto the card. I suggest you also read the section about backing up the calibration data while you are at it.

[@hullinstruments]

Would love to see your opinion and review of the DE 5000 LCR meter. Thanks for all of your honest info! I Feel like I’m stuck in a feedback loop “vacuum” sometimes on these forums! Nice to hear a change of opinion.

[@joesmith-je3tq]

I had thought about buying one of the DER EE LCR meters before. I have a couple of old BKs. It may be interesting to see how a modern low cost meter like the DER EE compares. The videos are basically me running the same tests across multiple meters. My opinions are formed from the data I collect. There's a lot more tests to run on these EEVBLOG meters so stay tuned.

[@hullinstruments]

joe smith Thanks for getting back with me! Yes I think you will be very impressed with the DE-5000. Also you should check into building one of the “leakseeker 89” kits. I just built one and I can tell you it is a very impressive piece of gear! I will always be sure to have one on my bench! With the leak seeker and the DE 5000, I can quickly trace down 90% of all faults! The leakseeker Is made by EDS, although now the only way you can build it is in kit form. The same company also makes a device called the cap Analyzer, which is great… But the DE 5000 Takes its Place....and offers many more functions. Hope you can get your hands on these devices! And if you are into faultfinding test gear, I’ve got a list of other great devices that are super useful for the bench! Some of the modern curve tracer kits sold on eBay really come in handy, along with The wonderful ESR multimeter adapter!

[@joesmith-je3tq]

@@hullinstruments I may have used something like your leakseeker. Does it have a headphone jack where you can listen while you sweep the board? The name doesn't sound right but that cheapo device saved my butt hunting down bridges on a very complex, dense board.

[@kemalnottaturk2500]

Is there any chance we will be able to get access to the log of hardware changes needed to make the 121GW usable? I use my July 2018 kickstarter unit for testing batteries. I use a Fluke 289 elsewhere.

[@joesmith-je3tq]

Usable in what way? You can already reprogram with as much firmware as you like. What else do you want to do with it? LOL! Seriously though, I have no idea of how many variances were released and what all the changes are. I also have no idea what impact each change has on the meter's performance. This is something you would need to ask Dave. I'm sure you're not the only one who would like to know.

[@jimalcott760]

Good video, thanks.

[@PCBWay]

Impressive!

[@gabeeg]

In part one...I believe you stated that you were also going to test the latest production firmware on the GW? I believe it is at 2.x now (I do not own one but have it on my list). Looking at the change log it looks like the only changes they note are "Resolved calibration glitch with V2.00 firmware. Reduces the Offset in the 50-ohm range." and "Improved the Auto-ranging reading speed in both capacitance and resistance ranges." But who knows what other tweaks or fixes are not noted. In any case testing or comparing with the latest production firmware would be helpful and give a better comparison between the GW, other meters and GW with older firmware. (I wrote the above comment right before the update to 2.02 in the vid!...of course...but question still stands, I would like to see more testing with 2.02 as comparison) Keep the vids coming, love your reviews.

[@joesmith-je3tq]

2.02 was loaded onto that meter in the previous video to try and see if it had any effect on the problem I was seeing. I've also included several screen shots where I show the filter roll off and noise for the various versions of firmware that I had looked at. I just linked a video in the EEVBLOG forum where I repeat Dave's settling time demo. You should have a look.

[@sepertude]

Please get that better Hioki meter if possible

[@ahmedalshalchi]

But they sell it more expensive than FLUKE products ...

[@joesmith-je3tq]

I ran a poll. People wanted to see the Gossen.

[@gotj]

Should have put the Aneng there too :-)

[@Mark-me7qq]

I think I will spend my money on a fluke.

[@ahmedalshalchi]

hahaha .... FLUKE oh FLUKE , they are usual f...king budget killer...

[@chrisblank9090]

fluke and keysight..

[@Kaxlon]

Best money I ever spent was buying my Fluke 73. It's been through hell. A friend didn't trust us on that our Swedish 240 volt easily put out over 10 amps. Before we realized he shoved the meter in A mode into the socket... Yeah it survived but that friend is scared shitless about electricity I think. =)

[@mtkoslowski]

Ahmed AlShalchi : Superior meters though.

[@TheAmmoniacal]

Brymen is the best bang/buck in multimeters, I'd take Keysight over Fluke for the high-end.

[@chrisblank9090]

fluke agilent and brymen.. the best choices

[@joesmith-je3tq]

After seeing that detent spring crack all four prongs on the Keysight meter, I lost interest in looking at another. That was a really big miss on their part and I can't help but think, if they can't design a simple spring, what about the rest of the design.

[@chrisblank9090]

joe smith sir, I have 2 u1242Bs, a blue version and an orange one, and a u1272A. I never had problems with them sir. the blue u1242b's almost 9 years old and is still doing fine. the orange one and that 1272 we bought 5 years ago. we use them everyday in our shop sir same with the flukes we have. maybe it depends on the model sir. I had a u1231 before too and after a year it started doing weird readings and when I looked inside I saw them pcb contact switch pads grooved by those spring contacs in the rotary switch assembly. they're pressing too hard on those pcb contact pads and I thought that was an issue or design flaw regarding that model. what we did was, we retrofitted it with another set of spring contacts that are much more flexible from a donor chinese meter, and covered up the grooved pcb pads with copper sheets electroplated with 10 karat gold. that 1231 is a bad model and needed some work to be fit for use again sir.

[@joesmith-je3tq]

@@chrisblank9090 That's pretty sad that you would have to modify a brand new production meter from a name brand like Keysight. It certainly doesn't do anything to increase my confidence in the brand. I doubt I would look at another.

[@chrisblank9090]

joe smith sir that was a fun experience. we made it work better by fixing the issue and after that there were no more problems with the meter. we also had a problem with our 189 2s when datalogging solar panel readings outdoors. also fixed it by putting some soft rubber ontop of the i.r slots. also with our 1 87 5 when we worked on a telecom tower's power house the meter went heywire. fixed it by adding aluminum tape shielding on the inside. even the top of the line brand like fluke had some issues with some of their models. the nice thing of it is that they're easy to fix sir. unlike that eevblog meter. we can't fix it's software issues sir. unreliable in the field in my opinion