CurtPalme.com Home Theater Forum

[gasser]

Barco split 809.

What setting will correct this?

TY,
Wes

[Francisco]

line of coincidence... reset block and redo alignment. mostly horizontal/ vertical skew and bow is causing this.

[gasser]

OK, but if only I knew how to reset the block.

[CasetheCorvetteman]

Reset all memories in the service menu.

[Hulio]

Here some advice, courtesy of " crt projectors.co.uk ", once, the main Barco installer in the UK :


" Q: I have an odd horizontal line visible at times, what is it?
A: At times you may see a horizontal line that fades in the middle of the picture but it quite visible at one end (often the right side), it will be most visible on bright scenes, all white fields or light blues. This is called the horizontal line of coincidence, to some extent it's natural on some models of projector but careful adjustment can remove or at least minimise it. Pause a scene where the line is plainly visible, note which side it shows the most, go to a genlocked pattern and adjust horizontal skew to lower the horizontal centre line on the opposite side to the worst one. Do this by only a small amount, say 4-5 clicks. Now adjust top and bottom keystone to correct the error the skew change introduced. Go back to the picture, is the line less? If it's worse you skewed the wrong way, if it's better carry on tweaking the skew and keystone to minimise or remove the line. You may end up with a horizontal skew error that's plainly visible on the test pattern, it should not be obvious on actual video. Excessive use of horizontal bow may also make the line worse, again it should be possible to reduce the effect by adjusting horizontal bow and correcting the resulting top / bottom bow errors. Removing the line completely may not be possible but you should be able to reduce it to an acceptable level. The line is caused by the projector set-up making several scan line converge as they cross the tube face, result: one large visible scan line.
If deflection coil angles are set wrong or the projector is not mounted flat it will not be possible to remove the line. To check deflection coil angles check the projector is flat with a spirit level, check the screen is flat with a spirit level, sent horizontal skew to 49, delete convergence settings for that block (see this answer). Go to convergence and exactly centre red and blue on green using only the middle zone (actually raster shift). Now check the green horizontal line is parallel with the ground and that both red and blue exactly match green. If anything is wrong you have deflection coil angle problems. Correcting this will require all blocks to be deleted and the projector set to mid point in the service menu. At this point also check raster widths at approximately the scan frequency you intend to use (do this on an internal test pattern), this may save you a lot of convergence problems, including instability.
If you bought your projector from us deflection coil angles are definitely right, we do all projectors on an engineers table. If you seem to have a problem make sure the projector is mounted level. If deflection coil angle was set for a ceiling install and the projector is floor mounted there will be some error, and vice versa. "

[gasser]

Hulio, that is a great explanation and I couldn't have found that. Thanks. I do have my CRT tubes mounted at an angle with my split pack, and do not want to mount the box flat as I would hit my head. But I did solve the problem.

I was fortunate enough to have a spare convergence tray. I replaced the tray with the other, now have a terrific picture.
The line of convergence is still there, however it is now very, very dim "white", only noticeable if you're really looking for it, not distinctive green bluish, so barely noticeable unless you are looking to "see it".

It would be terrific to see a 909 split pack next, out of curiosity, not because the picture would be much better, because I am pretty happy with my picture.
I would have to say, without other than the gamma and brightness adjustment I made off the AVIA DVD, no expensive colorimeter readings, it's a great picture.

Lucy off Redbox was a fantastic visual, colorific experience.

[gasser]

Thank you

[Hulio]

No problem Wes, glad you sorted out.
You may consider posting some pics on the screenshots thread

[gasser]

Good idea, but nothing compares to Curt, Francisco and the other wizards so I will appreciate my picture quietly with my family and friends.