CurtPalme.com Home Theater Forum

[akajester]

I'm having an issue getting the left side blue converged. What's strange is that about 1ft inward the blue is too far to the right, but on the left edge the blue is too far left. So, I can get it in the middle but it looks pretty bad. Thankfully it's worst on the top left which is typically not important in most movies. You can really notice it in 16x9 stuff though.

I've made sure the pj is square and level. I don't notice this problem running 720p but the problem worsens the higher resolution you go, so it looks pretty bad at 1080p. I'm running the rasters far enough from the edge so that shouldn't be causing an issue.

Any ideas?

Thanks!

[Ile]

Blue width coil adjustment could help (use non metallic tool) it have also effect to horizontal linearity, first check that yoke is fully against tubes bell.

If it's not helping. Then adjust picture to more right inside raster using Hphase and then move picture to center of the tubes face with raster sift. Then you can also try add more pixels to sources back porch timing, that makes more room to adjust picture to right inside raster.

[zGman]

If this is truly an "S" model - after matching the width w/ coils
then you should use "coarse" convergence horizontal blue.
this is essentially a linearity adj. Vert coarse is essentially
a key balance. These are basic & fundamental adjustments
for Barco S series.
G

[akajester]

Thanks for the pointers guys. It'll take me a little while to digest the information. I still feel pretty new to crt's.

[zGman]

OK - a couple barco tips....there's lots more in the manual...

First, the best results are always achieved by first clearing all memories,
and then going into zone astig and setting all zones to midposition.
Check that all focus zones are set to midposition. Start with your highest
input frequency (1080P)

Be certain all convergence zones and coarse convergence settings
are at midposition before starting setup. Basic height, width, and
H & V position are handled by pots and coils. I like to use a displaymate
grid external pattern to do geometry. Avoid use of raster shift.

Be aware that adjusting the cpc magnetics will cause shifts in position,
also be aware that excessive use of zone atstig and zone focus can
cause unsolvable convergence issues.

You will need to iterate a solution for red and blue - especially with
the issue you brought up - as you use coarse convergence to match
the sides, it will change the centering in the tubeface, and you then
have to look in the tube and use the centering pots, and then you
can set the mechanical toe-in. Always turn down the contrast before
you look in the lens.

I believe the manual is available on the this website - spend some
time with it - once you get used to Barco's terminology, you will
find it very very helpful.

Good Luck,
Galen

[secstate]

Galen's tips are very good the only thing I will add is I had a similar problem on red with a Barco Data 808s. Couldn't get the left side converged to save my life on red. Turns out there was skew in the tube. Hard to describe. But when I made the horizontal center line of red level (as per the Barco manual for adjusting the yokes) it skewed the vertical and this caused a similar convergence problem to what you are seeing. The only way I fixed it was by splitting the difference between horizontal level and vertical "level" on red via yoke adjustment. It took a bit of trail and error but I got it. The way to see if this is your problem is to reset everything to mid-point and look if either the blue center horizonal line or or center vertical line are signficantly skewed from their respective green counter parts.

I have seen other reports of this issue which seems to manfiest in some S series Barco 808 units. It seems more common on red for some reason (based on past google searches) but I seem to recall at least one report of it on blue as well.

[akajester]

Thanks secstate. I did have this problem with red before, but didn't think to check the blue as well. thanks.

[akajester]

Ok, I had a major breakthrough last night. Just feel like I learned alot but I still have left edge flaws.

So, I deleted all the blocks, reset everything to midpoints, including going through the astig zones and resetting them. Also reset all focus to midpoints. I learned that the previous owner must've messed with the astig because it was all over the place and didn't make sense. I sent it the signal from the htpc I wanted (resetting powerstrip to default 1920x1080p first.

I got out the laser level and adjusted the yokes. I had the same issue that secstate mentioned, the red was not level. I also noticed the blue was off a little. so adjusted both of those. I did the mechanical toe-in. Then noticed that the red was an inch or so high and the blue was almost 8" too high!!!! I made all the adjustments using the pots, including the blue linearity which was off as well and got them almost perfectly matched. sweet!

I used the master width pot to get the width close to where I wanted it. Then used powerstrip to adjust the porches to slide the picture to the right, as it was almost a foot off of center.

I ran through the guided setup, adjusting optical focus as best I could. didn't need to make any focus adjustments in the menu, it really looked pretty good. I adjusted all the sides to fit the screen and used the laser level to help with the bows and skews. Everything good so far.

On to convergence. Because I had the rasters centered so well, convergence was almost perfect without even touching it! I was amazed. I made a few tweaks here and there. Now. The left edge blue is still off. It is a little better. Before it was off up to a foot inward and on the edge. now it seems like the portion a foot inward is slightly better and the leftmost blue is still just as bad.

The one thing I didn't quite understand was checking if the yoke is against the tube bell. Do I just loosen it and push it towards the front of the crt? Also what is the blue width coil adjustment?

Any suggestions?

Thanks again for all the help everyone. I feel like I learned a ton last night. The picture does look crisper and cleaner.

[Ile]

[akajester]

Thanks Ile, this is excellent info!

[zGman]

Also, if you can post a screen shot of your external input set-up grid,
we may be better able to understand the problem(s) and work toward
a solution.
Congrats on your long night of CRT fun....ahhh - the good old days...
G

[akajester]

finally found the width coils. wow, they were really tucked in between those cards! anyways, futzed with it and got it the best I could. This is where I'm at. It doesn't seem to be improving much although the blue is definitely changing.



Also, I noticed that the red seems "pinched" vertically on the right side, so the left side is taller than the right. hmm.

Thanks.

[akajester]

I noticed that when turning the blue coil that the left seemed to squeeze inward but the right side seemed to go outward toward the right edge of the screen. I guess for some reason I thought they would expand from the center or contract towards the center. Maybe I'm just not understanding the adjustment yet.

What is the best way to make this adjustment. Should I reset everything to midpoints again?

Thanks!

[Gerbrand]

This issue looks very familiar to me. I think it is due to the so called "raster-ringing" from which all Barco's suffer more or less. Basically the raster has not yet fully stabilised at the left side of the image.

So basically you will need to shift the image a bit to the right with respect to the raster. This can be done by increasing the back porch on your source, or, but by reducing the H-phase in the geometry menu.

Gerbrand

[akajester]

I tried both of these options and neither seemed to help. I messed up the blue width coil so ended up putting it back to match the green. It's strange, like I can adjust things but as soon as I go back to do fine convergence it's right back to where it started.

[secstate]

That looks exactly like how my red behaved when it had a skew. With everything set to midpoint and the horizontal line level (per Barco's instructions) my center red vertical line was skewed sort of like \ rather than | as compared to green . The only way I could make red align on green was to make red horizontal line NOT level (despite what Barco states) and basically split the difference between horizontal being level and vertical being perpendicular if that makes sense. It is hard to describe but basically if your center horizontal like is skewed compared to green (i.e., not perpendicular to floor) it can cause this problem. The only way to minimize it (I never completely got rid of it) was to make vertical more perpendicular to floor at the cost of perfect horizontal level. However you have to move it only a bit at a time otherwise you end up pushing convergence on the horizontal side too far and that is a bigger issue since it impacts the middle of you screen. It took a bit of trail and error but I mostly got rid of the issue on my Data 808s.

[akajester]

But the blue appears to be set perfectly to green mechanically but in the end I get a stray bar on the left. Do you think I should skew it purposefully and see if it converges better? this really has me puzzled.

[akajester]

Anyone else have this issue. I'm still curious how to fix it. Thanks.

[km987654]

Are the rasters centred on each tube and is the image inside the raster?

[Elaine Benes]