I am placing this in the "beginner" section because of my ignorance, but this relates to the discussion about the 87V and the GSM problem.
I know there is a significant difference between the 87-III and 87-V. (lets' leave the 87-IV out of this, as it is really a 187 and a different type of meter) Lacking any knowledge to explain any better, the 87-V "boots up" so to speak with the "F87" screen, while the earlier models just turn on.
The older, square "70 series" (I call these "70 type") and the tapered 70 series (I call these "70 tapered type") are the older architecture (is that the correct term?)
The newer 170, 87-V and others are the newer architecture.
I wonder if the older 87s are less affected by the GMS signal? I wonder if the 170 series is affected just as the 87-V.