[Amps] Hi-pot testing
kd7jyk at earthlink.net
Fri Feb 12 19:40:13 EST 2021
"Just sitting there, it started making an arcing noise (sort of) and
showed plate current jumping around. "
New here, so mostly lurking, but this brought back memories of many
issues over the years. Have you checked for dust? I've run into this
many times, especially in TV's, and video displays, my experience with
tube amps is limited, although I have a few. Hyper-fine dust sticking
to things, and causing tracking, and eventually arcing. I took apart a
hallicrafters TV to show to a friend (assuming the issue would exist),
and there it was around the high voltage rectifier tube, fine dust, with
some blackened areas due to corona.
One of the very first things I do when inspecting, is gently blow out,
or vacuum any dust, and if possible, wash parts, boards, frames, cases,
connectors, et cetera before applying power, especially with high
Depending on the component, I use 91% rubbing alcohol, or QD Electric
Contact Cleaner, then let dry very thoroughly. Sometimes I use a small,
soft nylon bristled brush to scrub away really tenacious crud.
More information about the Amps