Author Topic: EEVBlog 121GW Discussion thread  (Read 560726 times)

0 Members and 1 Guest are viewing this topic.

Online joeqsmith

  • Super Contributor
  • ***
  • Posts: 7701
  • Country: us
Re: EEVBlog 121GW Discussion thread
« Reply #825 on: June 10, 2018, 02:54:22 pm »
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.   
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
Software, documentation and test reports for the low cost NanoVNA & V2 Plus 4 may be found here:
https://github.com/joeqsmith
 
The following users thanked this post: Kean, ChunkyPastaSauce

Offline VK5RC

  • Supporter
  • ****
  • Posts: 2560
  • Country: au
Re: EEVBlog 121GW Discussion thread
« Reply #826 on: June 10, 2018, 09:45:27 pm »
'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.
Whoah! Watch where that landed we might need it later.
 

Online EEVblog

  • Administrator
  • *****
  • Posts: 32892
  • Country: au
    • EEVblog
Re: EEVBlog 121GW Discussion thread
« Reply #827 on: June 12, 2018, 12:02:23 am »
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.

 :phew:

Glad to see it still works (all functions?)
 

Offline Kean

  • Supporter
  • ****
  • Posts: 1225
  • Country: au
  • Embedded systems & IT consultant
    • Kean Electronics
Re: EEVBlog 121GW Discussion thread
« Reply #828 on: June 12, 2018, 01:30:15 am »
:phew:

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.
 

Offline IanB

  • Super Contributor
  • ***
  • Posts: 9932
  • Country: us
Re: EEVBlog 121GW Discussion thread
« Reply #829 on: June 12, 2018, 06:29:27 am »
Apropos of nothing, either both of these meters are correct, or both of them are wrong:  :)

I'm not an EE--what am I doing here?
 

Offline IanB

  • Super Contributor
  • ***
  • Posts: 9932
  • Country: us
Re: EEVBlog 121GW Discussion thread
« Reply #830 on: June 12, 2018, 06:50:35 am »
Seems like a bunch of posts above just disappeared?
I'm not an EE--what am I doing here?
 

Offline Seppy

  • Supporter
  • ****
  • Posts: 189
  • Country: au
  • Curious
Re: EEVBlog 121GW Discussion thread
« Reply #831 on: June 12, 2018, 06:52:43 am »
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 :)
 

Offline IanB

  • Super Contributor
  • ***
  • Posts: 9932
  • Country: us
Re: EEVBlog 121GW Discussion thread
« Reply #832 on: June 12, 2018, 06:54:56 am »
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?
I'm not an EE--what am I doing here?
 

Offline Seppy

  • Supporter
  • ****
  • Posts: 189
  • Country: au
  • Curious
Re: EEVBlog 121GW Discussion thread
« Reply #833 on: June 12, 2018, 07:13:57 am »
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
« Last Edit: June 12, 2018, 08:07:08 am by Seppy »
 

Offline TMM

  • Frequent Contributor
  • **
  • Posts: 444
  • Country: au
Re: EEVBlog 121GW Discussion thread
« Reply #834 on: June 12, 2018, 10:11:06 am »
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 :-//
 

Online mikeselectricstuff

  • Super Contributor
  • ***
  • Posts: 12494
  • Country: gb
    • Mike's Electric Stuff
Re: EEVBlog 121GW Discussion thread
« Reply #835 on: June 12, 2018, 05:22:00 pm »
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.
 
Youtube channel:Taking wierd stuff apart. Very apart.
Mike's Electric Stuff: High voltage, vintage electronics etc.
Day Job: Mostly LEDs
 
The following users thanked this post: ChunkyPastaSauce

Offline 1anX

  • Regular Contributor
  • *
  • Posts: 195
  • Country: au
Re: EEVBlog 121GW Discussion thread
« Reply #836 on: June 13, 2018, 02:03:25 am »
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 :-//

 :palm:
 

Offline morris

  • Newbie
  • Posts: 1
  • Country: au
Re: EEVBlog 121GW Discussion thread
« Reply #837 on: June 14, 2018, 12:36:47 am »
Got mine today ;D. 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. ;D
https://youtu.be/nL7wDFNH8hM

Thank you Seppy and Admin   :-+
« Last Edit: June 15, 2018, 08:55:05 am by morris »
 

Offline Seppy

  • Supporter
  • ****
  • Posts: 189
  • Country: au
  • Curious
Re: EEVBlog 121GW Discussion thread
« Reply #838 on: June 14, 2018, 01:24:46 am »
Got mine today ;D. 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. ;D
https://youtu.be/nL7wDFNH8hM

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

Online EEVblog

  • Administrator
  • *****
  • Posts: 32892
  • Country: au
    • EEVblog
Re: EEVBlog 121GW Discussion thread
« Reply #839 on: June 14, 2018, 03:51:24 am »
Got mine today ;D. 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. ;D

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

Online EEVblog

  • Administrator
  • *****
  • Posts: 32892
  • Country: au
    • EEVblog
Re: EEVBlog 121GW Discussion thread
« Reply #840 on: June 14, 2018, 03:52:39 am »
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.
 

Online EEVblog

  • Administrator
  • *****
  • Posts: 32892
  • Country: au
    • EEVblog
Re: EEVBlog 121GW Discussion thread
« Reply #841 on: June 14, 2018, 03:54:26 am »
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.
 
The following users thanked this post: SeanB

Offline bicycleguy

  • Regular Contributor
  • *
  • Posts: 184
  • Country: us
Re: EEVBlog 121GW Discussion thread
« Reply #842 on: June 14, 2018, 04:36:18 am »
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.
« Last Edit: June 14, 2018, 04:38:42 am by bicycleguy »
 
The following users thanked this post: Mr.B

Offline Seppy

  • Supporter
  • ****
  • Posts: 189
  • Country: au
  • Curious
Re: EEVBlog 121GW Discussion thread
« Reply #843 on: June 15, 2018, 12:42:17 am »
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.
 

Offline Octane

  • Regular Contributor
  • *
  • Posts: 102
  • Country: us
Re: EEVBlog 121GW Discussion thread
« Reply #844 on: June 15, 2018, 01:01:56 am »
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
« Last Edit: June 15, 2018, 01:04:06 am by Octane »
W4MFT
 

Offline Kean

  • Supporter
  • ****
  • Posts: 1225
  • Country: au
  • Embedded systems & IT consultant
    • Kean Electronics
Re: EEVBlog 121GW Discussion thread
« Reply #845 on: June 15, 2018, 01:45:06 am »
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.   ;D

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

Offline IanB

  • Super Contributor
  • ***
  • Posts: 9932
  • Country: us
Re: EEVBlog 121GW Discussion thread
« Reply #846 on: June 15, 2018, 02:43:10 am »
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...  :P
I'm not an EE--what am I doing here?
 

Offline Seppy

  • Supporter
  • ****
  • Posts: 189
  • Country: au
  • Curious
Re: EEVBlog 121GW Discussion thread
« Reply #847 on: June 15, 2018, 05:05:46 am »
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.   ;D

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.
« Last Edit: June 15, 2018, 05:07:29 am by Seppy »
 

Online Brumby

  • Supporter
  • ****
  • Posts: 10866
  • Country: au
Re: EEVBlog 121GW Discussion thread
« Reply #848 on: June 15, 2018, 05:03:38 pm »
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.
 

Offline benst

  • Regular Contributor
  • *
  • Posts: 77
  • Country: nl
Re: EEVBlog 121GW Discussion thread
« Reply #849 on: June 17, 2018, 01:02:11 am »
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.

I have an iPad Pro 12.9 inch. (And a 121GW obviously. :) ) Let me know if I can help.

Ben
I hack for work and pleasure.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf