Author Topic: EEVblog 121GW Multimeter Issues  (Read 181733 times)

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Offline beanflying

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Re: EEVblog 121GW Multimeter Issues
« Reply #800 on: December 23, 2018, 01:04:25 pm »
Hi,

beside of the unacceptable slow autorange in ohms mode there is another issue in this mode.

......

That is the point! The 121GW has the most powerful processor in its class but is as slow as a 20 Euro multimeter with autoranging.
...

Only twice in the last week but as this is your issue to keep flogging go ahead I guess the Aliens on the dark side of the moon may not have heard you yet ::)

Taking a quick look at a few of your posts in this thread you purchased your meter in August knowing full well of the auto range speed and yet you keep raising it as life ending? Why did you buy it if you were going to be so effected by it?

You seem to have played with several things broken them and fixed them and had more problems than any one else at a rate of several problems per post. It is a strange thing but those of us who are happy and have left our meters relatively alone have far less issues. Is there a tip there for others?
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Offline GeoffreyF

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Re: EEVblog 121GW Multimeter Issues
« Reply #801 on: December 23, 2018, 02:48:31 pm »

You are a very good examble how not to discuss technical issues....

Rather than claiming someone else is as an "examble" - show what you are as an example to emulate.  You didn't.  If you believe you have a good point, make it with clear methods and actual numbers.  Reference the specifications you believe it doesn't meet or reference a use case that this meter doesn't meet and another does.   If nobody cares about your issue - don't repeat it.  People will still not care and you will appear tedious and annoying.

Be an example yourself.  The rest of us can decide which exemplar is the one we wish to emulate. 
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Offline AlanS

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Re: EEVblog 121GW Multimeter Issues
« Reply #802 on: December 31, 2018, 06:35:14 am »
Has anyone seen an error message 5d.E03? It appears to be an data logging error code.

It occurs when I start data logging to an internal SD Card. After pressing MEM to start the logging, it starts and then fails with the above message. I have used data logging to the card multiple times and this error only occurred today. I am using the current firmware - and couldn't find any reference to this message on the forum.

BTW - where do we find out what the other error codes are?

Good product for my purposes.
 

Offline barjammar

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Re: EEVblog 121GW Multimeter Issues: Activate Bluetooth on Meter??
« Reply #803 on: January 09, 2019, 04:33:32 am »
Hi, I may have missed it but is there an instruction on how to use the Bluetooth “activate Bluetooth on the meter” as I can’t see the meter on my iPhone or in the app.
Many Thanks.
Barry
 

Offline GeoffreyF

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Re: EEVblog 121GW Multimeter Issues: Activate Bluetooth on Meter??
« Reply #804 on: January 09, 2019, 12:13:04 pm »
Hi, I may have missed it but is there an instruction on how to use the Bluetooth “activate Bluetooth on the meter” as I can’t see the meter on my iPhone or in the app.
Many Thanks.
Barry

Yes, it is in the manual.  Page 53 as follows:

To enable Bluetooth communications, hold the “1ms PEAK” button until BT is displayed on the LCD.
Ensure that Bluetooth is enabled on the host device before running the application on the remote computing device.
The multimeter will continue to functional as normal in Bluetooth mode, but the display data will be transmitted via the Bluetooth connection.
To disable Bluetooth mode press and hold the 1ms Peak button until BT is not displayed.
 
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Offline Seppy

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Re: EEVblog 121GW Multimeter Issues: Activate Bluetooth on Meter??
« Reply #805 on: January 23, 2019, 03:44:38 am »
Hi, I may have missed it but is there an instruction on how to use the Bluetooth “activate Bluetooth on the meter” as I can’t see the meter on my iPhone or in the app.
Many Thanks.
Barry

With the iPhone it should be nearly instant, android and windows are much slower at detecting devices.
You don't need to pair the 121GW with the iPhone and it will not connect if it (the 121GW) is already paired to another device. Paired devices take precedence until they are unpaired.
BLE doesn't have much power, if your near other high power devices you might experience issues.
« Last Edit: February 14, 2019, 06:08:06 am by Seppy »
 

Offline 1anX

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Re: EEVblog 121GW Multimeter Issues: Activate Bluetooth on Meter??
« Reply #806 on: January 23, 2019, 07:54:55 pm »
With the iPhone it should be nearly instant, android and windows are much slower at detecting devices.
You don't need to pair the 121GW with the iPhone and it will not connect if it (the 121GW) is already paired to another device. Paired devices take precedence until they are unpaired.
BLE doesn't have much power, if your near other high power devices you might
"You might" what Seppy? Seems to have been accidentally edited out mid sentance?
 

Offline WattSekunde

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Re: EEVblog 121GW Multimeter Issues
« Reply #807 on: February 11, 2019, 12:37:03 am »
Manual 2019-01-29 vs. 121GW 1.57 in VA mode?

The Manual (p.20) shows 3 µVA ranges and 6 mVA/VA ranges in AC or DC. But I can select 4 ranges at the µVA position of the rotary switch and 4 ranges at the mVA/VA position. I don't get it.

Rotary Switch in position µVA input. MODE = AC or DC.
I see this decimal point positions. (RANGE) pressed between each step:
1. AUTO
2. ##0.00
3. ###0.0
4. ###0.0 ?
5. ####0
back to step 2
(Hold RANGE to go back to AUTO range)

Rotary Switch in position mVA/VA input. MODE = AC or DC.
I see this decimal point positions. (RANGE) pressed between each step:
1. AUTO
2. #0.000
3. ##0.00
4. ##0.00 ?
5. ###0.0
back to step 2
(Hold RANGE to go back to AUTO range)

 

Offline GeoffreyF

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Re: EEVblog 121GW Multimeter Issues
« Reply #808 on: February 11, 2019, 02:59:25 pm »
Manual 2019-01-29 vs. 121GW 1.57 in VA mode?

The Manual (p.20) shows 3 µVA ranges and 6 mVA/VA ranges in AC or DC. But I can select 4 ranges at the µVA position of the rotary switch and 4 ranges at the mVA/VA position. I don't get it.

Rotary Switch in position µVA input. MODE = AC or DC.
I see this decimal point positions. (RANGE) pressed between each step:
1. AUTO
2. ##0.00
3. ###0.0
4. ###0.0 ?
5. ####0
back to step 2
(Hold RANGE to go back to AUTO range)

Rotary Switch in position mVA/VA input. MODE = AC or DC.
I see this decimal point positions. (RANGE) pressed between each step:
1. AUTO
2. #0.000
3. ##0.00
4. ##0.00 ?
5. ###0.0
back to step 2
(Hold RANGE to go back to AUTO range)

Now actually measure something.  Your post is about manual selection, NOT ranging.   If you used your 121GW you would get  it.
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Offline bicycleguy

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Re: EEVblog 121GW Multimeter Issues
« Reply #809 on: February 11, 2019, 05:55:26 pm »
Manual 2019-01-29 vs. 121GW 1.57 in VA mode?

The Manual (p.20) shows 3 µVA ranges and 6 mVA/VA ranges in AC or DC. But I can select 4 ranges at the µVA position of the rotary switch and 4 ranges at the mVA/VA position. I don't get it.

Rotary Switch in position µVA input. MODE = AC or DC.
I see this decimal point positions. (RANGE) pressed between each step:
1. AUTO
2. ##0.00
3. ###0.0
4. ###0.0 ?
5. ####0
back to step 2
(Hold RANGE to go back to AUTO range)

Rotary Switch in position mVA/VA input. MODE = AC or DC.
I see this decimal point positions. (RANGE) pressed between each step:
1. AUTO
2. #0.000
3. ##0.00
4. ##0.00 ?
5. ###0.0
back to step 2
(Hold RANGE to go back to AUTO range)

version 1.58 works similarly.  The VA measurements are fairly confusing and the manual furthers the issue with ambiguity.

Only the designers (or someone who wants to spend a little time experimenting) can fully explain.  Here's some observations:

1. For each VA range there is a current reading with its range and resolution multiplied by a voltage reading with its range and resolution.  The exact selections for each are not given in the manual.  You may get some idea by the number of digits and units in the current and voltage readings that alternately flash on the secondary display.  But you don't know for sure if that means anything.
2. The math of resolution and range carry over is not defined.
3. Even which range is selected is not known as you indicated as the only indication is the # of digits and the uVA or mVa or VA symbol.

Most of this detail doesn't matter for the casual user and critical measurements should be made with separate voltage and current readings.

However, I think the manual should say a little more.


 

Offline WattSekunde

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Re: EEVblog 121GW Multimeter Issues
« Reply #810 on: February 11, 2019, 10:39:30 pm »
OK, let's say it's a manual issue but I can't check the multimeter against hidden information. The manual could have been created more carefully. I like the very clear Gossen manuals most.


BTW: I read nearly this whole thread and someone said there are not enough "active tester" reporting possible bugs. Until the VA strangeness I stumbled upon these days the 121GW worked fine to my needs. I like the very nice iOS App, too! But I also like a critical community who drives a product forward. Maybe with HW and SW hacks. That's the biggest difference between the 121GW and all other meters on the market. Let's take it apart...  :-/O  ;)
 

Offline GeoffreyF

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Re: EEVblog 121GW Multimeter Issues
« Reply #811 on: February 12, 2019, 01:33:38 am »
OK, let's say it's a manual issue but I can't check the multimeter against hidden information. The manual could have been created more carefully. I like the very clear Gossen manuals most.

But you can use it.  You will see the ranges.  Even in your report on pushing the range button, you noticed two ranges that were the same.  No they aren't. They just look that way at zero.   The purpose of the range button is to give the meter a hint as to where to start.  That doesn't mean that's the only place.  USE IT!  It's really there.  Try to measure something and if its to a limited number of decimal places, check the spec. It's in spec.  You are simply confusing the ranges and accuracy with the use of the range function!   Actually use it on a project.
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Offline Alex Rodriguez

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Re: EEVblog 121GW Multimeter Issues
« Reply #812 on: February 26, 2019, 02:45:17 pm »
The 121GW bluetooth is not working. I have the iPhone XS MAX firmware iOS 12.1.4 - I turn ON the 121GW bluetooth, and search for it on my phone, not joy. The iPhone never finds it, as a result the application is not working.  I installed the latest 1.58 121GW beta firmware, still no joy.
 

Offline GeoffreyF

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Re: EEVblog 121GW Multimeter Issues
« Reply #813 on: February 26, 2019, 04:10:22 pm »
It works for me on Android.   When the meter is first turned on, bluetooth is off.  Did you turn it on, as discussed in the manual?  It would be helpful if you wrote the steps you used to use bluetooth.   Generally speaking - the bluetooth feature works.
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Offline Alex Rodriguez

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Re: EEVblog 121GW Multimeter Issues
« Reply #814 on: February 27, 2019, 04:39:31 am »
It works for me on Android.   When the meter is first turned on, bluetooth is off.  Did you turn it on, as discussed in the manual?  It would be helpful if you wrote the steps you used to use bluetooth.   Generally speaking - the bluetooth feature works.

Yes, I turned bluetooth  ON, I followed page 53 instructions. I pressed the "1ms PEAK," and I see the "BT" on the screen, but the iPhone does not see the meter at all.  So the application is blank.
« Last Edit: February 27, 2019, 04:42:49 am by Alex Rodriguez »
 

Offline bicycleguy

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Re: EEVblog 121GW Multimeter Issues
« Reply #815 on: February 27, 2019, 05:51:21 am »
Alex
The bluetooth has been very reliable on a iPhone and iPad.  All I can suggest is that you try to remove the 121GW from the background tasks to get a fresh start.  So quit the app, double click to see the background apps and swipe up to stop it.  Then try opening it again.  I don't thing you have to restart bt on the 121gw.

good luck
 

Offline imaradiostar

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Re: EEVblog 121GW Multimeter Issues
« Reply #816 on: March 01, 2019, 04:48:33 am »
I'm a new forum member and I searched, so please help me understand if my post breaks rules!

My other (high count) meters are a Fluke 8060a and 8050a, and a Keithley 2015THD. All are capable of displaying dBv in one way or another. On the 8060a I have to use relative mode, but once given a reference voltage, it plays nicely and is very accurate. Arguably, it tracks the 6.5 digit meter better than the 121GW.

I can't seem to get the 121GW to play nicely. It'll display dBm (a useless metric in 2019 for all but the most select circumstances, I would argue) but I can't take advantage of relative mode in reference to the dB display. As a result, I'm unable to directly display measurements in dBv or relative measurements, such as the gain of an amplifier.

I can always get out a calculator and 20*log(acv2/acv1), but the whole point of a fancy meter is to NOT have to do that!

Can anyone address this for me? It seems dBv should be available, and on the MAIN display.

thanks!

Jamie
 

Offline newbrain

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Re: EEVblog 121GW Multimeter Issues
« Reply #817 on: March 01, 2019, 07:57:30 am »
It'll display dBm (a useless metric in 2019 for all but the most select circumstances, I would argue)
I'd beg to differ. It does not make much difference if the the display is in dBm or dBV or any other dBxxx. A reference level is needed in any case.

I can always get out a calculator and 20*log(acv2/acv1), but the whole point of a fancy meter is to NOT have to do that!
And, in fact, you don't need to do that. Just measure the dBm value at the input, and subtract it from the dBm at the ouput...though I agree that being able to use Rel would be nice (I stand by your words on this, I'm away from home at the moment).
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Offline imaradiostar

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Re: EEVblog 121GW Multimeter Issues
« Reply #818 on: March 02, 2019, 02:52:20 am »
It'll display dBm (a useless metric in 2019 for all but the most select circumstances, I would argue)
I'd beg to differ. It does not make much difference if the the display is in dBm or dBV or any other dBxxx. A reference level is needed in any case.

I suppose it comes down to your intended purpose. I still think that dBv makes the most sense. If a meter has a sufficiently high impedance, it's "invisible" to any circuit under test, so an external termination of any given value could be connected. I live in an HP/Agilent dominated analog world where dBv is by far the most common comparison point. If I'm reporting amplifier gain or frequency response, it's always a dBv thing. I'm sure other labs/work environments are different, of course. I used to work in pro audio and I can see why they like dBu/dBm with a 600 ohm reference.

My lab does RF and audio frequency work. I mostly work in audio, so dBv seems to be the most useful, as it is referenced to a voltage and not a given impedance.

I guess my opinion is unfair to those that prefer dBm. I am hoping for more dialogue about what is possible with the hardware. If the meter has an internal dc reference and is programmable, perhaps it could be programmed to have multiple reference impedances/voltages, like the Fluke 8050a did in 1980. In any case, the ability to at least use relative measurement mode means that someone could measure the gain of a circuit and provide their own reference impedance/voltage/terminator.

If dB made it to the primary display rather than just the secondary field, it could be manipulated withe the relative measurement function, as has been done in other meters.

Jamie
 

Offline newbrain

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Re: EEVblog 121GW Multimeter Issues
« Reply #819 on: March 02, 2019, 10:27:39 am »
Emphasis added by me:
If a meter has a sufficiently high impedance, it's "invisible" to any circuit under test, so an external termination of any given value could be connected. I live in an HP/Agilent dominated analog world where dBv is by far the most common comparison point. If I'm reporting amplifier gain or frequency response, it's always a dBv thing.
The meter impedance remains around 10 M \$\Omega\$ when in dBm mode, it does not use a 600 \$\Omega\$ load: it is, in fact, measuring dBu not dBm.
To report gain, one just uses dB: it's a pure (power) ratio, no m, u or V. A subtraction in dBx is all that is needed (easier to do in my mind than logs and ratios).
The value in dBV is a also simple subtraction away:
dBV ~= dBu - 2.22
I'm sure you don't need the calculation spelled out, that's one of the advantages of using a logarithmic measure!

So to wrap it up, there are for sure improvement points:
  • The display should have read dBu, rather than dBm.
    I think most people don't care, and it's a bit late now (LCD change).
  • Rel key should also work for the secondary display when in dBm mode (so it becomes a pure dB mode).
    This could be definitely done in firmware1: show the difference in measured values on the main display, and the dB difference on the secondary.
    It would be slightly confusing (=expect someone to complain  :horse:), as the main display will show a difference and the secondary a ratio2, but still handy.
At the same time, I still don't see any major advantage in one dBx over the others (I would have been just as happy with dBV, really...).

1: The internal DC reference and its programmability have nothing to do with it. The displayed dBm value is just a fixed calculation on the measured AC value.
Storing the dBm reference value along the AC value (or recalculating it from the latter) and doing a subtraction is all that it takes.
2: e.g. Measure (and display) 1.00V / 2.218 dBm, hit Rel, then measure 2.00V: display is now 1.00V / 6 dBm
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Offline imaradiostar

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Re: EEVblog 121GW Multimeter Issues
« Reply #820 on: March 04, 2019, 05:27:39 am »
You're right, the LCD should say dBu. That's why in my post above I said dBm/dBu (saying 600 ohm reference added confusion), because obvious the meter has no internal termination. dBu makes sense, and I can do the -2.2 as easily as the next person. Or I can use a Fluke 8050a and not bother. For that matter, when I'm doing low-noise EIN and gain testing, I usually use a Fluke 8920a anyway.

Most folks don't care. I get that. I am not complaining, but I am to some extent responsible for purchasing stuff like this for our lab. For less than the cost of a Fluke this meter appeared to meet our needs better. I'm just trying to understand it so I can help the other engineers and techs.

I would like to request, if such a thing is allowed, that a dB mode be implemented with the ability to select a reference voltage. As you stated, that shouldn't be hard to implement. Once the AC measurement has been made it's just background number crunching. In my lab we'd set all of them to dBv and everyone would be happy. I love that the meter remembers stuff through power cycles, by the way. Very cool.

Jamie
 
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Offline ascomm

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Re: EEVblog 121GW Multimeter Issues
« Reply #821 on: March 06, 2019, 11:06:31 am »
I've been noticing that the mA/A current mode always shows a reading of 0,10...0,12 mA current even when there is no test leads connected to the multimeter. Is that normal or is it some bug in firmware etc?
 

Offline beanflying

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Re: EEVblog 121GW Multimeter Issues
« Reply #822 on: March 06, 2019, 11:28:33 am »
I've been noticing that the mA/A current mode always shows a reading of 0,10...0,12 mA current even when there is no test leads connected to the multimeter. Is that normal or is it some bug in firmware etc?

Something to do with the Op-Amps on the input warning circuit causing them to float up a bit with no current flow? Haven't looked thoroughly so just a rough idea. Mine sits at 0.25 mA open and drops to 0.0029mA shorted. Open terminals can also suffer from external induced voltages depending on the circuit, my Agilents on GOhm input range can develop 10V+ open.

EDIT: Bit more of a look there is also the Caps across the inputs of the Burden voltage circuit so no current they will likely float up.
« Last Edit: March 06, 2019, 11:35:53 am by beanflying »
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Offline MaTkEOxjC

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Re: EEVblog 121GW Multimeter Issues
« Reply #823 on: March 13, 2019, 09:29:32 am »
+1 for proper bug tracking system, it's not easy to look for already reported bugs in 14 16 pages of thread.

I second that. It's kinda meta but I see this as a bug.
For potential buyers it would be very interesting which bugs exist, which are unfixable(e.g. hw bugs) or won't be fixed and which are fixed or UEI is working on.
Also there seems to be no change-log (just looked at fw 1_57) whatsoever.

Digging through 34 pages of a forum Thread is insanity.
 
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Offline GeoffreyF

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Re: EEVblog 121GW Multimeter Issues
« Reply #824 on: March 13, 2019, 01:34:38 pm »
+1 for proper bug tracking system, it's not easy to look for already reported bugs in 14 16 pages of thread.

I second that. It's kinda meta but I see this as a bug.
For potential buyers it would be very interesting which bugs exist, which are unfixable(e.g. hw bugs) or won't be fixed and which are fixed or UEI is working on.
Also there seems to be no change-log (just looked at fw 1_57) whatsoever.

Digging through 34 pages of a forum Thread is insanity.

Is there a product which fits with your vision of bug tracking?   Did you look for it?  The meter complies with it's specification.  It does what it says on the tin.  So why theorize about a benighted process for this particular product which I think would actually be pretty unique in the industry.  Because of its relationship with this forum, there is a lot more information about this meter than others.
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