Great tests , at list about the Fluke 87-5 we certainly know now , the guilty frequency ...
In my hole I have also GSM network , and as more difficult the area , the mobile transmits with higher watts so to help for an balanced communication.
It was an big surprise that 3G has no effect , but at the end of the day , you never know what type of network your mobile are up to , because it switches all the time by it self ..
Because of my hole , I had switch manually on GSM .
Testing other DMM at the same condition was very reviling also.
Oh my I was screaming Dave in all the video , like ........... take the damn phone away ......
Amazingly it did not bricked .
But believe it or not , you was close enough .
I did not had the chance to do such testing on my DMM , by getting my mobile phone close to it ,
in just 15 seconds it turned off , and become an brick .
If some one cares to spot the deference's , he must visit the specific thread link
https://www.eevblog.com/forum/index.php?topic=1251.0It could be the revision of the DMM it self ..
Some 87-5 to be more sensitive to fail than others .... who knows..
I posted high resolution pictures at the page 4 .
My congratulations about the video , its so reviling , and a great confirmation , about the problem.
Lets hope that the company , it will stand on the side of the people.
Starting by helping me out , and anyone in need, because of this specific issue ..