Author Topic: EEVBlog 121GW Discussion thread  (Read 390911 times)

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Offline darik

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Re: EEVBlog 121GW Discussion thread
« Reply #1550 on: June 03, 2019, 05:26:51 am »
OK , a video with a 47K , even with no touching  hands , just the bench noise . If I move the meter away from the table it is stable , but obviously something is not right

https://streamable.com/giz9s

 :-DD
 

Offline beanflying

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Re: EEVBlog 121GW Discussion thread
« Reply #1551 on: June 03, 2019, 05:28:17 am »
OK , a video with a 47K , even with no touching  hands , just the bench noise . If I move the meter away from the table it is stable , but obviously something is not right

https://streamable.com/giz9s

You have a switchmode supply within 50mm of it and you want to be taken seriously? Please tell us that it and other nearby SMP's are not near the leads  :palm:
Coffee, Food, R/C and electronics nerd in no particular order. Also CNC wannabe, 3D printer and Laser Cutter Junkie and just don't mention my TEA addiction....
 

Offline EEVblog

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Re: EEVBlog 121GW Discussion thread
« Reply #1552 on: June 03, 2019, 05:32:42 am »
OK , a video with a 47K , even with no touching  hands , just the bench noise . If I move the meter away from the table it is stable , but obviously something is not right

All multimeters have a tolerance for electric fields, some even specify a V/m field strength for the the accuracy. Looks like you are in a potentially horrible environment there, evidenced by the problem going away when you move it away from your bench.
 
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Offline CDaniel

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Re: EEVBlog 121GW Discussion thread
« Reply #1553 on: June 03, 2019, 05:34:34 am »
That power outlet with USB power supply in it has a switch and wasn't turn on  ;D
Nothing was turned on on the bench , just the normal electrical noise from the wires
 

Offline Smafe

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Re: EEVBlog 121GW Discussion thread
« Reply #1554 on: June 03, 2019, 06:51:48 am »
Hi Dave, I wasn't having a whinge (apart from the back light flashing briefly when the meter turns on). I'm grateful for all the help you've given me over the past couple of years. I did rename the file, but I put it on a different Micro SD card. It was the card out of my phone and I wasn't sure which way to format it, so tried formatting in Windows 10. That must have been the problem as when I put the bin file on the original card and booted it from there it worked. I was worried as I couldn't remember whether to rename the zip or extract the bin file. It sounds stupid now, but I've only updated the firmware once before and that was when I first received the meter and updated straight to V1.57. I love the 121GW. I've got both your meters, cases, lots of fuses, and even brought a BM235 for a friend! I'm still a beginner and try my best, and am sorry for the annoyance.
 

Offline EEVblog

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Re: EEVBlog 121GW Discussion thread
« Reply #1555 on: June 03, 2019, 07:12:40 am »
Hi Dave, I wasn't having a whinge (apart from the back light flashing briefly when the meter turns on).

I'm not sure why people hate this so much, I like to think it's a little exercise of the battery and the backlight every time.
 
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Offline Smafe

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Re: EEVBlog 121GW Discussion thread
« Reply #1556 on: June 03, 2019, 09:23:48 am »
Maybe, like me, people worry that it means something is wrong? If its nothing to worry about, then I won't give it another thought. I'm loving the faster response time. Thank you.
 

Offline Uncle Bob

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Re: EEVBlog 121GW Discussion thread
« Reply #1557 on: June 03, 2019, 09:54:32 am »
Hi Dave, I wasn't having a whinge (apart from the back light flashing briefly when the meter turns on).

I'm not sure why people hate this so much, I like to think it's a little exercise of the battery and the backlight every time.

I thought it was the flux capacitor that was leaking.   :phew:

 ;D
 

Offline BrianG61UK

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Re: EEVBlog 121GW Discussion thread
« Reply #1558 on: June 03, 2019, 10:43:20 am »
Hi Dave, I wasn't having a whinge (apart from the back light flashing briefly when the meter turns on).

I'm not sure why people hate this so much, I like to think it's a little exercise of the battery and the backlight every time.

Well it's exactly the right length, at exactly the right moment, to make one wonder if something might be wrong in the rotary switch, contacts making in the wrong order or something. If it were a deliberate self test type thing one would expect it to be a little longer and perhaps synchronized with a beep. But it's fine once you know it's okay.
 

Offline CDaniel

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Re: EEVBlog 121GW Discussion thread
« Reply #1559 on: June 03, 2019, 11:10:38 am »
Hate is too much but that flash of light at start-up looks like a lack of programming finesse ... I doubt it is intentionally there . But if the rest of the firmware would be perfect I doubt peaple would "hate" it .
« Last Edit: June 03, 2019, 11:15:49 am by CDaniel »
 

Offline joeqsmith

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Re: EEVBlog 121GW Discussion thread
« Reply #1560 on: June 03, 2019, 12:03:52 pm »
OK , a video with a 47K , even with no touching  hands , just the bench noise . If I move the meter away from the table it is stable , but obviously something is not right

https://streamable.com/giz9s

That power outlet with USB power supply in it has a switch and wasn't turn on  ;D
Nothing was turned on on the bench , just the normal electrical noise from the wires

The prototype Dave provided is pretty sensitive to low frequency changing magnetic fields.  Eventually, I will have a look at the released version.  It may be interesting to repeat the testing with the 121GW along side the shielded Gossen in the chamber and see how it does against my Fluke 189 and the Brymen BM869s (as a reference).   Was hoping the dust would settle in a year after the kick start, but no word yet on the thicker PCB.  Hopefully it will be available yet this year.   

https://youtu.be/_u_34E5ZUOI?t=144
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline CDaniel

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Re: EEVBlog 121GW Discussion thread
« Reply #1561 on: June 03, 2019, 12:40:48 pm »
In some internet videos , including David's videos , if you look carefully you can see abnormal changes in readings when touching or moving the hands near the probes .
This should be measurable by injecting some AC 50/60Hz voltage in resistance mode . I think the firmware is not using enough low pass filtering at the ADC input . HY3131 has a switchable capacitor and some resistors for this .
« Last Edit: June 03, 2019, 12:47:43 pm by CDaniel »
 

Offline 286sx

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Re: EEVBlog 121GW Discussion thread
« Reply #1562 on: June 03, 2019, 07:04:14 pm »
2.0 released !

tested... much more faster on resistance and capacitor measurement.
 

Offline 636steve

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Re: EEVBlog 121GW Discussion thread
« Reply #1563 on: June 06, 2019, 01:33:54 pm »
I have just upgraded to v2 software and everything seems fine except I can't turn the backlight on anymore. is anyone else seeing this. Admittedly I have not used the backlight for a while so might not have been working before I upgraded the firmware.
 

Offline chronos42

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Re: EEVBlog 121GW Discussion thread
« Reply #1564 on: June 06, 2019, 04:37:27 pm »
I have just upgraded to v2 software and everything seems fine except I can't turn the backlight on anymore. is anyone else seeing this. Admittedly I have not used the backlight for a while so might not have been working before I upgraded the firmware.

I have no problems with the backlight and v2.
 

Offline jancumps

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Re: EEVBlog 121GW Discussion thread
« Reply #1565 on: June 06, 2019, 04:48:04 pm »
Same here. Worked before and after the update.
 

Offline bicycleguy

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Re: EEVBlog 121GW Discussion thread
« Reply #1566 on: June 06, 2019, 09:14:04 pm »
@chronos42
Mine works ok.  Just curious, do you get the light flash when first turning on?
 

Offline PoLoMoTo

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Re: EEVBlog 121GW Discussion thread
« Reply #1567 on: June 07, 2019, 12:21:42 am »
This may be a silly question or already answered but I was wondering what this slot on the back of the rubber case is for, picture attached.  Wasn't sure what to search to figure it out.
 

Offline beanflying

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Re: EEVBlog 121GW Discussion thread
« Reply #1568 on: June 07, 2019, 12:28:16 am »
This may be a silly question or already answered but I was wondering what this slot on the back of the rubber case is for, picture attached.  Wasn't sure what to search to figure it out.

Use the slot for something like this eBay auction: #132926318720 or I have been going to do something with 3D Printing and a good magnet but as I don't do much work is metal cabinets it isn't that important to me.

Coffee, Food, R/C and electronics nerd in no particular order. Also CNC wannabe, 3D printer and Laser Cutter Junkie and just don't mention my TEA addiction....
 
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Offline EEVblog

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Re: EEVBlog 121GW Discussion thread
« Reply #1569 on: June 07, 2019, 05:26:50 am »
This may be a silly question or already answered but I was wondering what this slot on the back of the rubber case is for, picture attached.  Wasn't sure what to search to figure it out.

It fits UEI's magnetic hanger, but I don't actually sell that.
 
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Offline wilfred

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Re: EEVBlog 121GW Discussion thread
« Reply #1570 on: June 07, 2019, 01:35:07 pm »


Use the slot for something like this eBay auction: #132926318720 or I have been going to do something with 3D Printing and a good magnet but as I don't do much work is metal cabinets it isn't that important to me.


Use the magnet to hold screws so you don't lose them.
 

Offline chronos42

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Re: EEVBlog 121GW Discussion thread
« Reply #1571 on: June 07, 2019, 01:43:59 pm »
@chronos42
Mine works ok.  Just curious, do you get the light flash when first turning on?
Yes, I still get the light flash. Not sure if this is a intended feature or a short undefined state after power on, but I do not have any problem with this behaviour.
 

Offline Roelof

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Re: EEVBlog 121GW Discussion thread
« Reply #1572 on: June 07, 2019, 04:23:43 pm »
It fits UEI's magnetic hanger, but I don't actually sell that.

This one, I assume:
https://www.ueitest.com/products/accessories/amh1
 

Offline e0ne199

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Re: EEVBlog 121GW Discussion thread
« Reply #1573 on: June 09, 2019, 12:11:25 pm »
hello i have a question...
does 121GW multimeter have differential probe for measuring current? i want to measure current around more than 10 Amps on my device anyway
answer is really appreciated, thx before
 

Offline dadler

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Re: EEVBlog 121GW Discussion thread
« Reply #1574 on: June 11, 2019, 05:29:52 am »
hello i have a question...
does 121GW multimeter have differential probe for measuring current? i want to measure current around more than 10 Amps on my device anyway
answer is really appreciated, thx before

A differential probe for... current? What is your use case?

Without more information or your requirements (AC or DC? Contactless or resistive current measurement? Are the sources isolated?), the following methods may work.

Multiple 121GW meters can connect to an Android device or Windows PC via Bluetooth, and math functions can be performed against the connected meters. You could simply take the subtraction of the readings between two connected meters.

Resistive:
  • 2x 121GW meters (or any oscilloscope with simple math functions + some milliohm-scale power resistors)
  • An Android device or Windows PC (if using the 121GW)
Contactless:
  • 2x 121GW meters (or any oscilloscope with simple math functions)
  • 2x hall-effect current sensors, such as the PDI CA-60
  • An Android device or Windows PC (if using the 121GW)

It may be more cost-effective (and offer greater insight) to use a cheap oscilloscope such as a Rigol DS1054Z than multiple 121GW meters. Depending on your requirements, you could also build a circuit to do this, and measure it with a single 121GW (or any other meter or oscilloscope).

But answer the specifically asked question: no, the 121GW doesn't have any differential probes.
« Last Edit: June 11, 2019, 10:28:15 am by dadler »
 


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