[Username1]

Hi - I believe your problem is some kind of spike in the Horiz. Osc. Signal
that is then sent to the Horiz. Output. While doing a freeze-frame on yer
video, I can see what looks like a a spike or reduction in amplitude of
the horiz. Scan line. Making a few scan lines run long or short. You can
also see the Damper circuit faithfully reproduces the effect over on the left
side of the screen. That makes me think it's source is Before the Horiz Output
tube, and Damper circuit. I would look over in the Horiz. Osc. area as being the
cause. Effects of the spike, well, larger, or shorter scan for that instant,
possibly raise or lowering of B+ Boost? Raise or lowering of HV? Anyway, to me
it looks like a Horiz Osc. Origin - I did not look at the schematic, but you know
it's so short in duration, and intermittent, you may just need to change
parts to get it..... Of course it's possible for some type of discharge somewhere
else to be causing a spike to give you this display, you will have to figure out
if you have a HV arc somewhere.... It would be really neat to get this problem
figured out down to a single part, and post it's location on a schematic because
the effect is just so different.....

Good Luck.

.