Meck XB-702 restoration

[bandersen]

Originally Posted by Kevin Kuehn

Here's a set with a similar problem at about 1:00 in the first video.

https://www.youtube.com/watch?v=Ygpw87pqTz0

https://www.youtube.com/watch?v=aSEMVpJ1hzk

It sure does. That's a series string, floating chassis if I recall correctly.

Originally Posted by Notimetolooz

Another thing is that the problem seems to go away when you move the CRT away from the chassis.
I just had a thought.
When you look at some of the signals with the scope, like the sync, does the hum look stationary with respect to the sync pulses or does the position slowly move ?

The problem does not go away when I move the CRT away. At least not horizontally. Perhaps it's a little better vertically.

The hum moves slowly with respect to the sync. If I trigger my scope from the line, the hum locks in place.