CurtPalme.com Home Theater Forum

bomrat · Joined: 10 Mar 2006 Posts: 117 Location: chicago

what would cause this.. banding on the right. is it from the coils? its happening on all three tubes. can't turn up the contrast above 50

**AnalogRocks** · Posted: Sun Nov 18, 2007 4:01 am Post subject:

Do you mean the banding on the other right? Wink

bomrat · Joined: 10 Mar 2006 Posts: 117 Location: chicago

uh, on the left

**AnalogRocks** · Posted: Sun Nov 18, 2007 4:17 am Post subject:

Unrelated to your 9500 but I had that on a CRT monitor. Replacing the VGA cable fixed the problem. Not sure if that's what you are seeing though.

jask · Joined: 17 Mar 2006 Posts: 10187 Location: kamloops BC

what is your source? did this just start?

nuttall_chris · Posted: Sun Nov 18, 2007 2:17 pm Post subject:

Every Marquee I have see does this when the retrace option is set to short. Change retrace to long and that "banding" will go away.

This has nothing to do with cables as it occures on the internal test patterns as well. It is on all colours.

One problem is that many source devices use very short porches and with retrace set a long the picture will be clipped off on both sides, setting retrace to short can help the clipping of the picture but the side effect is this "banding" on the one side of the picture.

Chris.

bomrat · Joined: 10 Mar 2006 Posts: 117 Location: chicago

mike parker, please call ken w...

schmoe · Joined: 30 Mar 2008 Posts: 374 Location: Seattle, WA

I have this exact same issue with a 9500 I'm trying to set up and it's really annoying. Is there anything that can be done? I'm using short retrace. If long retrace is the cure, how do I change my signal to work with long retrace? My setup: DVDO Edge -> HDMI -> HDFury2 -> RGBHV -> 9500.

stefuel · Posted: Sun Feb 22, 2009 12:28 pm Post subject:

Confused? Not banding but raster ringing.

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

there is a tech bulletin on this i think. But it might be for the right side not left. And Chip is right its ringing VDC calls it jail bar
ringing i think.
If its on the internal test patterns only, this Bulletin might help

http://www.curtpalme.com/docs/ElectrohomeMarqueeTechnicalBulletin_VDCDS_TFB_003.pdf

It might help even with external images also i believe, not sure.

Athanasios

secstate · Joined: 20 Mar 2006 Posts: 720

Yeah Barcos do this too, especially when they go into hi scan mode.

tse · Joined: 03 May 2006 Posts: 1014 Location: Sweatbucket, Fl.

It sure looks like ringing caused by short retrace. If you have to use short retrace phase the external image as far to the right as necessary to avoid the bars. You might have to use the convergence shift (center adjustment) to put the picture back in the middle.

Scott

stefuel · Posted: Sun Feb 22, 2009 6:47 pm Post subject:

Just so ya know, this condition is not specific to Marquee's. The condition can be duplicated with just about every crt projector. One more reason not to sway to far from factory recommended mounting instructions. It's one of the trade-offs
from insisting on using as much of the tube face as you can eeek out of it.

schmoe · Joined: 30 Mar 2008 Posts: 374 Location: Seattle, WA

nuttall_chris · Posted: Sun Feb 22, 2009 9:34 pm Post subject:

Mark_A_W · Posted: Sun Feb 22, 2009 10:29 pm Post subject:

My XG will do it too.

Chris is bang on with the cause.

To fix it you need more porch pixels (I can't help with the Marquee specific retrace settings), and reduce the width/size setting.

More porch pixels/reduced width will mean that you may have to more the projector back...closer to the factory settings...to fill the screen.

If I want to eliminate the ringing on my XG at 1080i 96hz I really need to move the projector back.

stefuel · Posted: Sun Feb 22, 2009 11:31 pm Post subject:

"This has nothing to do with mounting position."

If you say so. I guess I've been told Laughing

nuttall_chris · Posted: Mon Feb 23, 2009 12:01 am Post subject:

secstate · Joined: 20 Mar 2006 Posts: 720

CIR Engineering · Posted: Mon Feb 23, 2009 2:08 am Post subject:

This is most likely the worst with 1080p right?

It's raster ringing, and all projectors that I have seen do it to some degree or another. The best fix to improve the situation is to position the image as far to the left (when looking into the tube) on the raster as you possibly can (away from the leading edge). The farther the edge of the image is from the start of the raster the more time the beam will have to settle down.

This happens with high scan rates because the beam has to go from -40 IRE all the way up to the image IRE level (and you are probably showing a 100 IRE field in the photo so 140 IRE jump?). When the beam does this, it shoots past the IRE level desired and then oscillates for a spell. That's what makes those waves in the picture.

If you are using a VP or HTPC you can do as others suggest and increase your porch sizes, to make the raster bigger, to allow for even further positioning of the image away from the edge. However, keep in mind that when you increase the pixel count you also draw more bandwidth and your image may become softer.

The G90 is the best projector in terms of being able to make this distortion almost invisible, but you can still see it if you know what to look for.

craigr