RCA 21CT55 B8802897 is Alive!

[Tomcomm]

The replacement of the height pot and .047uf amp feedback cap made a major improvement in vertical height and linearity stability. The sequential pictures show the cross hatch and circle pattern improving during warm up. Although better, it is still entirely too long a time for performance demonstration.
The black felt pen dots applied directly to the CRT screen represents the ideal circle locations and are very useful in judging the results of any circuit modification. My 55 can be expected to present a useful screen for casual viewing in about 10min after turn-on and reach maximum picture quality for critical screen shots in about 1hr. Convergence has not been optimized since vertical performance is the issue here.

Is my 55 unique with this problem or do all CTC2B chassis and maybe all RCA CTVs up thru CTC10 have this same problem to some extent? I would like to see sequential screen shots of member's early RCA's during warm-up. Ideally they would use the same DVE DVD cross hatch and circle pattern I use, and would apply the felt pen dots directly to the CRT glass for reference.....Tom