Ran across an older Fluke 87 at work that was blown up on the DC side. I was going to repair the front end, but ran across a strange modification on one of the MOV's. Threw it in a bin and haven't thought of it in a while.
The MOV has a notch cut into the top that runs down about 1/5th of the diameter. Looks like it was done with a Dremel cutting wheel, very deliberate and clean.
Just wondering if anyone has run across a MOV with a notch cut into it, and what is the purpose of such a modification, (blast direction, part derating etc.). Seems a wonky mod that I wouldn't expect from Fluke.
Thanks.
edit - added picture of spark gap capacitor (thanks Sean for ident on this beast) with notch, unit is a 85 III true RMS