I have cleaned with contact cleaner and paper tape pretty extensively, but can always go another round.

I do not think that is a good waveform, but similarly, no idea.

-Eric

On Sat, Aug 5, 2023, 7:23 PM Jeffrey Golas <jeffg@junknet.net> wrote:

Correct me if Im wrong but could just be "dirty"; as the cam rubs against the switch youre seeing noise like a dirty volume pot.

Id use some alcohol and a business card and scrub the contacts (plus Im not sure thats even a terrible signal for a 1940s device. Going machine to machine I dont think that tiny bit of leakage woulda mattered.

Again, correct if wrong, Im here learning too.

Jeff KC3GJX