Any thoughts?

[bigaudioal]

Wow! That's a ton to digest!

[earlyfilm]

Originally Posted by bigaudioal

Wow! That's a ton to digest!

Big Al,

Either you narrow down the search area, or you check every component that you replaced, then every tube and component that you didn't replace. I think that you'll decide that to it is much easier to narrow down your search area with a few simple tests.

After a recap, always take a bright light and a magnifying glass and check all freshly soldered connections for cold joints. Gently wiggle the wires and see is something moves that should not. Observe how the solder flowed. It should flow outward, not inward on the connecting wires, if correctly done.

In my first post, I should have mentioned the obvious:

First substitute the damper and horizontal output tube.

Without any tests, my best guess by probability is:

1) Damper tube.
2) Miswired or mis-adjusted Horiaontal linearity coil. (Check those three caps for value) (Same for Horizontal Lock coil, & cap, just in case)
3) Too much horizontal drive (trimmer too tight) and mis-adjusted width coil to compensate.
4) A combination of 2) and 3).
5) Wrong value, wrongly connected or omitted capacitor.

Big Al, refresh my memory. Do you have a 'scope?

If so, the first thing to do is to check to see if the waveform on the grid of 6BQ6 matches slight hump in the sweep as shown on the diagram.

Originally Posted by old_coot88

Um.. (discounting the CRT) if the extra brightness in the center remains unchanged, it would mean it is sweep-derived (ie., horiz getting into the video).
It wouldn't matter whether the horiz is synched to the station or not.

My goal with this test was to get the sync off the station frequency to better define the problem.

>>> If the extra brightness remained in the center, it would indicate either defective CRT or Damper circuit and/or B-Boost issues.

The latter two are more probable, as there was horizontal ringing showing up youtube video in the final post on the other thread. It is also possible that Bob overcorrected while adjusting the horizontal drive and/or horizontal linearity and/or width.

>>> If the brightness in center disappeared (it would have moved to the diagonal lines where it would be almost impossible to see), that would indicate CRT was OK and the damper was probably working correctly and sweep was relatively linear.

Note: One also could have done this test by tuning a unused channel, but doing so could complicate the test by accidentally introducing symptoms that are unrelated to the present problem.

James