EEVBlog 121GW Discussion thread

[Scottjd]

Ifyou look at the pictures the steel plated one at about a 50mm length can support a 100g weight. The pure nickel bent and fell through the vise so I pulled the weight off and just set it aside.
It’s been a while since I was so active in a thread. Well it’s been fun, but I’m having issues typing now with my finger cramping up so I’m going offline.

[fanOfeeDIY]

It wouldn't damage any meter with a proper CAT rating.

OTOH it might skew the test results by giving some meters a head start. eg. Nether the Fluke nor the Hioki are showing "0L" at the start of each test.

Thanks, Fluke 87V and Hioki DT4282 are not showing OL.
The fluke and hioki are the ones have lower current on measuring ohm and it might related to it.

Also, it might be behaving differently when scanning between the ranges to find the right range.

Well, I am a lazy person.

[fanOfeeDIY]

Ok, so it’s a technicality but this idea might work?
You don’t BUY anymore, just do what some other youtubers do.
Contact bangood and they will send you meters. Then your not buying any of them.
I personally don’t work with bangood so I don’t know how it works. But as long as you disclose it’s from a vendor before the video review or testing I don’t think many people watching care that much these days.
Off the top of my head in the genre of electronic YouTube channels I can think of 3 or 4 that get items all the time from bangood and they still have high subs and views, so it probably doesn’t matter much.
This way you can keep your DMM addiction going without buying another one. 
[/quote]

I started to take videos just for my fun in my time, one was to keep my English.

If I become more serous of taking the video in the future, then I might need to think the content of the video with more meters.

The main concern is taking spaces in the room at the moment. (I think)

[fanOfeeDIY]

There's a place that sends you free multimeters? For free?

Don't let that information reach the therapy thread. 

There’s a therapy thread? Please share, my best friend needs multimeter obsession help. 

https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/

 

[fanOfeeDIY]

I found this video where he pulls apart the Yokogawa.  Looks like they have some sort of gas tubes.   The Gossen used GDT's and held up very well in the transient tests.  The Keysight meter I looked at also used GDTs and was damaged early on in the testing.   

Does your meter look the same inside as this one?

Sorry for scaring people that I am not uploading images on the forum.
(I am not killed yet for having too much meters)

I just finished taking high resolution images.
I found some of the images which I took after the last video were not showing good for uploading to eebvlog.
I was considering to take the some images again, then I became busy.

I will upload them soon.

[nidlaX]

Is there a more concrete timeline available for the shipping of the US meters? I may need to change my address again if the meters don't ship within a few weeks.

[fanOfeeDIY]

Thanks for taking the pictures.   Looking forward to seeing them.

I finally uploaded them here.
https://www.eevblog.com/forum/testgear/ty720-kew-1062-handheld-multimeter-inside-high-resolution-images/

[knapik]

I got the switch shim fix and new knob and installed it today. The knob itself is much tighter now, and it seems to have helped the turning off issue I was constantly having near the Ohms and power selection. For a little bit, I was still having the same issue where the multimeter was turning off, but after a little bit of time, it seems to have settled in, and I can't replicate it even with some spirited jiggling.

[VK5RC]

Thanks, I also got the shim and new knob, went in well, definitely a bit firmer now - but I didn't have any problems before!

[ANTALIFE]

Looks like I am one of the unlucky ones that only got shipped a replacement knob but no shim ; - ;
Have contacted Dave to try and get the shim re-shipped

[1anX]

Looks like I am one of the unlucky ones that only got shipped a replacement knob but no shim ; - ;
Have contacted Dave to try and get the shim re-shipped

 

[morrone]

I had a fairly long logging session recently that logged DC V while charging a 12V battery.  I left it on the default logging rate, thinking that was once per second, but it turns out that my meter defaulted to "0", so according to the manual was actually logging at the fastest rate of around 200ms.

Around 25-26 hours later I went to the meter and saw a voltage of around 13.67V.  My victron BMV-712 told me that current down to nothing, so that was as far as the charger was going to take it.  I stopped the logging, and the beginnings and end of the log file look like:

START,2018/04/24,16:45:07,
ID,170800000,
INTERVAL,000,sec,
,MAIN,,,SUB-1,,,SUB-2,,,Remark,
No. ,Func. ,Value,Unit,Func. ,Value,Unit,Func. ,Value,Unit,
1,DCV,013.182,V,,,,,,,,
2,DCV,013.188,V,,,,,,,,
3,DCV,013.187,V,,,,,,,,
4,DCV,013.187,V,,,,,,,,
5,DCV,013.187,V,,,,,,,,
6,DCV,013.187,V,,,,,,,,
[cut]
364219,DCV,013.529,V,,,,,,,,
364220,DCV,013.530,V,,,,,,,,
364221,DCV,013.529,V,,,,,,,,
364222,DCV,013.530,V,,,,,,,,
364223,DCV,013.529,V,,,,,,,,
364224,DCV,013.529,V,,,,,,,,
364225,DCV,013.530,V,,,,,,,,
364226,DCV,013.529,V,,,,,,,,
MAX,67374,DCV,013.531,V,
MIN,1,DCV,013.182,V,

Something is very odd here.  The last sample was 13.529V, and the max was recorded as 13.531.

I am not sure what happened here.  It doesn't help that the meter only logs sample count, and not time.  If I really assume that it took a sample every 200ms, then the meter only logged for a little over 20 hours.  But I know that I stopped it a minimum of 25 hours later.  So, OK, 200ms is approximate.  So maybe its is more like every 250ms on average...that would work out to a little over 25 hours (after 364226 samples).

But if it really was logging up until the point that I stopped it, then why were there no records of the 13.67V readings that I saw on the display (and was also reported by the Victron BMV-712)?

[EEVblog]

I got the switch shim fix and new knob and installed it today. The knob itself is much tighter now, and it seems to have helped the turning off issue I was constantly having near the Ohms and power selection. For a little bit, I was still having the same issue where the multimeter was turning off, but after a little bit of time, it seems to have settled in, and I can't replicate it even with some spirited jiggling.

Maybe there was some form of contaminant on the pads or contacts that eventually wiped away?

[Seppy]

Looks like I am one of the unlucky ones that only got shipped a replacement knob but no shim ; - ;
Have contacted Dave to try and get the shim re-shipped

I have now shipped the part.

[Seppy]

I had a fairly long logging session recently that logged DC V while charging a 12V battery.  I left it on the default logging rate, thinking that was once per second, but it turns out that my meter defaulted to "0", so according to the manual was actually logging at the fastest rate of around 200ms.

Around 25-26 hours later I went to the meter and saw a voltage of around 13.67V.  My victron BMV-712 told me that current down to nothing, so that was as far as the charger was going to take it.  I stopped the logging, and the beginnings and end of the log file look like:

START,2018/04/24,16:45:07,
ID,170800000,
INTERVAL,000,sec,
,MAIN,,,SUB-1,,,SUB-2,,,Remark,
No. ,Func. ,Value,Unit,Func. ,Value,Unit,Func. ,Value,Unit,
1,DCV,013.182,V,,,,,,,,
2,DCV,013.188,V,,,,,,,,
3,DCV,013.187,V,,,,,,,,
4,DCV,013.187,V,,,,,,,,
5,DCV,013.187,V,,,,,,,,
6,DCV,013.187,V,,,,,,,,
[cut]
364219,DCV,013.529,V,,,,,,,,
364220,DCV,013.530,V,,,,,,,,
364221,DCV,013.529,V,,,,,,,,
364222,DCV,013.530,V,,,,,,,,
364223,DCV,013.529,V,,,,,,,,
364224,DCV,013.529,V,,,,,,,,
364225,DCV,013.530,V,,,,,,,,
364226,DCV,013.529,V,,,,,,,,
MAX,67374,DCV,013.531,V,
MIN,1,DCV,013.182,V,

Something is very odd here.  The last sample was 13.529V, and the max was recorded as 13.531.

I am not sure what happened here.  It doesn't help that the meter only logs sample count, and not time.  If I really assume that it took a sample every 200ms, then the meter only logged for a little over 20 hours.  But I know that I stopped it a minimum of 25 hours later.  So, OK, 200ms is approximate.  So maybe its is more like every 250ms on average...that would work out to a little over 25 hours (after 364226 samples).

But if it really was logging up until the point that I stopped it, then why were there no records of the 13.67V readings that I saw on the display (and was also reported by the Victron BMV-712)?

Just a few questions:
- Did you read the 13.67V on the 121GW or another device (Error potentially in reference)
- Does your 121GW measure 13.5V correctly if simply given DC (Error potentially in calibration)
- What version of firmware do you currently have (So I can test against that version)
- Did sample 67374 correlate to the 13.531 V MAX value?
- What was your charging setup?

[knapik]

I got the switch shim fix and new knob and installed it today. The knob itself is much tighter now, and it seems to have helped the turning off issue I was constantly having near the Ohms and power selection. For a little bit, I was still having the same issue where the multimeter was turning off, but after a little bit of time, it seems to have settled in, and I can't replicate it even with some spirited jiggling.

Maybe there was some form of contaminant on the pads or contacts that eventually wiped away?

I'm not too sure actually. I accidentally had the contacts in the wrong position for the first time I put the meter together resulting in all the positions being shifted, so when I took it apart again I rotated the contacts themselves to the off position before putting the dail back in. It did happen once again after I wrote my previous post, but its not something I can replicate consistently. It could be something like a bit of contamination, or the contacts being picky with the initial position. I'll mention it if I'm having any further issues with the multimeter resetting.

[Insatman]

I am not sure what happened here.  It doesn't help that the meter only logs sample count, and not time.  If I really assume that it took a sample every 200ms, then the meter only logged for a little over 20 hours.  But I know that I stopped it a minimum of 25 hours later.  So, OK, 200ms is approximate.  So maybe its is more like every 250ms on average...that would work out to a little over 25 hours (after 364226 samples).

Question...Does the 121GW log counts not time because it lacks a real-time clock?   Could some sort of time-stamp be implemented in the log data in future based on the calculated time from sampling frequency?   This would really be helpful.

[Cliff Matthews]

Question...Does the 121GW log counts not time because it lacks a real-time clock?   Could some sort of time-stamp be implemented in the log data in future based on the calculated time from sampling frequency?   This would really be helpful.

RTC is U7. Here's the data sheet.

[morrone]

Just a few questions:
- Did you read the 13.67V on the 121GW or another device (Error potentially in reference)

Yes, I saw 13.67V on the LCD display of the 121GW, and confirmed the value with another device before I ended logging by holding down the MEM button.  Both devices agreed fairly closely.  In hind sight, I probably should have made note of what the sample counter was doing on the LCD before ending logging.

- Does your 121GW measure 13.5V correctly if simply given DC (Error potentially in calibration)

I don't have any reason to believe that particular value is wrong.  The calibration reasonably matched a couple of my other meters last time I checked.  I'm running a log of a discharge cycle at the moment, but I will double check the calibration after that.  UPDATE: Yes, it matches two other meters quite closely measuring 13.5V.

- What version of firmware do you currently have (So I can test against that version)

1.10

- Did sample 67374 correlate to the 13.531 V MAX value?

Yes, sample 67374 was the first instance of 13.531V in the file.

- What was your charging setup?

This is in a travel trailer.  A WFCO WF-8735 is charging a Greenlife GL100 LiFePo battery (with built-in BMS to tolerate being used as a lead acid battery drop in replacement, even if it isn't ideal).  At the start of the log the WF-8735 is in constant current mode and was delivering just under 36A according to the victron battery monitor (the WF-8735 is rated for 35A, so that is fairly reasonable).  The leads of the 121GW are clipped directly to terminals on the battery posts.

The voltage in the logs gradually rises from 013.182V at the start to 13.531V at sample 67374.  After that the voltage hovers around 13.527V to 13.531V for the rest of the log.  I'm willing to share the log, but it is 11MB in size.

[Insatman]

Question...Does the 121GW log counts not time because it lacks a real-time clock?   Could some sort of time-stamp be implemented in the log data in future based on the calculated time from sampling frequency?   This would really be helpful.

RTC is U7. Here's the data sheet.

So...if it has an RTC...why not log timestamps?   Why make the user guess or try and figure it out...makes no sense.

[Iagash]

Update has been released to the app stores, likely hasn't updated on both yet but these issues should all be resolved now, we also have a new firmware version which will be resolving one of the other issues (when the voltage in VA mode is above 32767 approximately, this firmware update hasn't been released, this issue was a packet issue not a app issue so for those values you'll need to wait for the next firmware update).

Ok, with the new firmware 1.15 the wrong values in VA mode seem to be fixed. I still get checksum error on around 2% of the packets and the update rate seems to be reduced to about 2 packets per second.

Would you please push your app changes to the gitlab repo as I suspect the RangeLookup table in Packet121GW.cs has changed. I'd like to add your changes to my script.

Thanks!

[EEVblog]

v1.15 has been released, it's on the website for download. There are various small fixes.
Please everyone use that latest version when reporting issues, we want everyone on the same page.

Update on the shipping:
50 units coming to me on May 5th (the original lost 50), 1000 more units available from May 19th, and another 1000 units ASAP after that.
Kickstarter update will come tomorrow when I get back from holidays.

[VK5RC]

Sorry for being a bit slow but where is the current version ie which website?
Thanks

[djadeski]

You can find the files here: https://www.eevblog.com/product/121gw/

-dave

[kalross]

Did any European early birds get the shim sent to them yet?  My meter dial has started to play up and I haven't received the shim.