On Mon, 30 Apr 2018 18:43:11 -0700, Jeff Liebermann
wrote:
(...)

This kinda sounds like the arcing problem as described. The arcing is
from the winding to the carbon brush wiper:

Variac Repair using DeOxit:
https://www.youtube.com/watch?v=qRTKHNoiRQI

However, I'm not sure that's such a great idea. It looks like he
managed to burn up the Variac:
https://www.youtube.com/watch?v=po5Xxl_Syxg


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Jeff Liebermann
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