The Precise 9071 VTVM, Part 6: Let’s clean up the range switch.
Wednesday, November 11, 2026 at 08:38:00
The range switch is similar to the function switch, in that it’s covered with snot wire and old resistors. The precision resistors here are actually in good condition which surprised me. For the most part, all of the old carbon films I’ve worked with to this point were in terrible condition and changed values immediately upon being heated. These did not, so kudos to that 1950s manufacturer - whomever you are.
Let’s start by removing and examining.
Nothing really unusual here…but…
There’s another no-solder. This thing was full of them. Not that I haven’t missed a few on rebuilds, but that’s why you go back and check your work.
Removing the parts was fairly straightforward. I started with one side, and then worked on the other.
When everything was removed, it was cleaned.
And we ended up with a nicely cleaned switch, re-coated with grease and contact cleaner.
There’s still some wiring left to remove and a couple of pots to consider. We’ll do that in the next part.
Next part of this series: Coming soon.
Previous part of this series: https://wereboar.com … at-the-range-switch/