EEVBlog 121GW Discussion thread

[Kean]

Dave & other interested parties...

I have now remembered a time in the last few weeks I was measuring the 1200V AC output from a 100W Ultrasonic Transducer driver.  At the time I was pretty sure I only used my 15kV and differential oscilloscope probes - but based on the damage and Joe Smiths excellent test video, it seems likely that I must have tried to measure the voltage with the 121GW.

Very embarrasing, as I should gave known better!

Amazingly the meter still seems to function perfectly after cleaning the burnt area, and appears to still be in spec against my Keysight 34465A.

[joeqsmith]

Dave & other interested parties...

I have now remembered a time in the last few weeks I was measuring the 1200V AC output from a 100W Ultrasonic Transducer driver.  At the time I was pretty sure I only used my 15kV and differential oscilloscope probes - but based on the damage and Joe Smiths excellent test video, it seems likely that I must have tried to measure the voltage with the 121GW.

Very embarrasing, as I should gave known better!

Amazingly the meter still seems to function perfectly after cleaning the burnt area, and appears to still be in spec against my Keysight 34465A.

No reason to be embarrassed.  This is actually pretty good news.   

[VK5RC]

'Glad' to hear that someone else does stuff like I do! I just tried arc welding a dmm probe that slipped, measuring a 30v dc rail across a 10mF cap. D'oh.

[EEVblog]

Dave & other interested parties...

I have now remembered a time in the last few weeks I was measuring the 1200V AC output from a 100W Ultrasonic Transducer driver.  At the time I was pretty sure I only used my 15kV and differential oscilloscope probes - but based on the damage and Joe Smiths excellent test video, it seems likely that I must have tried to measure the voltage with the 121GW.

Very embarrasing, as I should gave known better!

Amazingly the meter still seems to function perfectly after cleaning the burnt area, and appears to still be in spec against my Keysight 34465A.

 

Glad to see it still works (all functions?)

[Kean]

Glad to see it still works (all functions?)

Yep - as mentioned above...

OK, I just ran through a reasonably comprehensive functional test of my "damaged" 121GW, and it all tested out perfectly, even BT.  The only mode that I didn't test (and haven't used) is the VA ranges.

I used an Advantest R6142 programmable voltage & current generator, an ITECH IT7321 programmable AC source, some resistance & capacitance decade boxes, a function generator, and some random diodes to hand.

I am actually pretty impressed it survived with so little damage actually, assuming that I did hit it with that 1200V 28kHz supply... which now seems entirely likely.

[IanB]

Apropos of nothing, either both of these meters are correct, or both of them are wrong: 

[IanB]

Seems like a bunch of posts above just disappeared?

[Seppy]

Ok just checked on my iPhone 5s. Logging “save” button works fine there. But still no joy on the iPad mini.

Seems like a bunch of posts above just disappeared?

I split the topic so that we can keep app beta testing separate from discussion, only a few testers around

[IanB]

I split the topic so that we can keep app beta testing separate from discussion, only a few testers around

OK, can you then move Reply #910 above to the other thread?

[Seppy]

I split the topic so that we can keep app beta testing separate from discussion, only a few testers around

OK, can you then move Reply #910 above to the other thread?

Done, new topic called "121GW App Testing". This is for the beta testers of the iOS App

[TMM]

Got mine today, working great. Only problem is that someone on the production line was a bit too much in the spirit of "don't turn it on, take it apart" because it is missing the screws from the back cover

[mikeselectricstuff]

Not read through all the posts to check if this has been discussed (and AFAICS the forum can't search a single thread), but it isn;t mentioned in the manual
 I notice that the mode setting is retained after power-off. Although this can be useful it can also be annoying, especially if the meter isn't used often. It would also be a pain for a meter that was shared by several users, or used by someone unfamiliar with it.
AFAICS there is no option to make it always power up in a consistent mode - I think this would be a useful addition.
 

[1anX]

Got mine today, working great. Only problem is that someone on the production line was a bit too much in the spirit of "don't turn it on, take it apart" because it is missing the screws from the back cover

 

[morris]

Got mine today . Good job, Dave
Can someone tell me how do I open the battery cover though? I have removed the two screws at the back but the cover just won’t come off.  Which direction shall I push/ lift? I don’t want to break anything  this soon Thanks!


Oh...got it .  But mine was kind of tight.
https://youtu.be/nL7wDFNH8hM

Thank you Seppy and Admin   

[Seppy]

Got mine today . Good job, Dave
Can someone tell me how do I open the battery cover though? I have removed the two screws at the back but the cover just won’t come off.  Which direction shall I push/ lift? I don’t want to break anything  this soon Thanks!


Oh...got it .  But mine was kind of tight.
https://youtu.be/nL7wDFNH8hM

For the battery cover it is difficult to remove if you don't pull precisely upwards.

[EEVblog]

Got mine today . Good job, Dave
Can someone tell me how do I open the battery cover though? I have removed the two screws at the back but the cover just won’t come off.  Which direction shall I push/ lift? I don’t want to break anything  this soon Thanks!
Oh...got it .  But mine was kind of tight.

You have to grab both sides and pull directly up. Yes it's a rather tight fit.

[EEVblog]

Not read through all the posts to check if this has been discussed (and AFAICS the forum can't search a single thread), but it isn;t mentioned in the manual
 I notice that the mode setting is retained after power-off. Although this can be useful it can also be annoying, especially if the meter isn't used often. It would also be a pain for a meter that was shared by several users, or used by someone unfamiliar with it.
AFAICS there is no option to make it always power up in a consistent mode - I think this would be a useful addition.

I don't believe there is an option to turn it off. The BM235 does the same.

[EEVblog]

Apropos of nothing, either both of these meters are correct, or both of them are wrong: 

Don't bother getting more, because it's turtles all the way down.

[bicycleguy]

Not read through all the posts to check if this has been discussed (and AFAICS the forum can't search a single thread), ...

To search a single thread go to the end of the thread and hit the print button.  You will get a single long page of html that you can do a text search on with cmd-F.

Edit:  Just testing this post I see you had 31 posts in this thread.

[Seppy]

We need a beta tester with an iPad Pro or an iPad with a resolution of 2732 x 2048. We need a few screen shots in that size for the App Store, its part of the submission process.

[Octane]

I have a 10.5” (2224-by-1668 Pixel) iPad Pro, but my meter didn’t arrive yet. Still happy to help if necessary.

Michael

[Kean]

We need a beta tester with an iPad Pro or an iPad with a resolution of 2732 x 2048. We need a few screen shots in that size for the App Store, its part of the submission process.

Could you not add a simulated device in the app that generates a slow sine wave or something.  Then you can just generate a nice screen shot via the iOS simulator, and people still waiting for the 121GW can start playing with the app.   

I have to admit I've not submitted a screen shot at that resolution in the past - maybe it isn't/wasn't mandatory.

[IanB]

I imagine you need a screen shot so that Apple can verify that you are scaling to that screen resolution correctly. And in fact, the higher resolution of the iPad Pro will be a problem without scaled fonts as the small text for < Settings > and < Maths > is already very small and difficult to read on an ordinary iPad. On a higher resolution device you will need a microscope... 

[Seppy]

We need a beta tester with an iPad Pro or an iPad with a resolution of 2732 x 2048. We need a few screen shots in that size for the App Store, its part of the submission process.

Could you not add a simulated device in the app that generates a slow sine wave or something.  Then you can just generate a nice screen shot via the iOS simulator, and people still waiting for the 121GW can start playing with the app.   

I have to admit I've not submitted a screen shot at that resolution in the past - maybe it isn't/wasn't mandatory.

This is an option but it is a fair amount of work (I also have to fake the multimeter screen, which is programmed to respond to packets, so I need to record a sessions packets and then replay them).
It would be more accurate and honest getting a real screen shot. I also am also not entirely sure it works on iPad Pro, wouldn't want to make it look like it did if it didn't.

[Brumby]

It would be more accurate and honest getting a real screen shot. I also am also not entirely sure it works on iPad Pro, wouldn't want to make it look like it did if it didn't.

You are right to not want to fake it.  It's not just dishonest, it is asking for trouble.  Actual screenshots on actual devices is the only real option.

Besides, the effort to fake a screen would be a one-off exercise = wasted time ... and any problems on those resolutions would need to be fixed anyway.  It's more efficient to just do it properly.