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faidros
Joined: 16 Jul 2010
Posts: 2
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| Posted: Fri Jul 16, 2010 11:25 pm Post subject: Raster width responce bg808 |
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Dear all enthusiasts.
I am struggling with the setup of a Barco graphics 808s. I started on a more detailed adjustment, and got stuck the Raster width coils. There seams to be no response whatever way I am adjusting. I tried to adjust all in and then adjust one and one outward - absolutely nothing happen with the raster.
I thought it might have something to do with the signal fed to the PJ. I tried with 15,6kHz - nothing. hooked up to my blu-ray - nothing. using the genlocked pattern - nothing.
entering the service menu, and choosing raster, and then adjust - nothing again.
What am I doing wrongly here? The PJ is working quite good besides this. I am of cause using plastic tools for adjust these pots.
Regards from Norway
Olav
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Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
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| Posted: Sat Jul 17, 2010 12:03 am Post subject: |
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There is no real reason to adjust those coils. They do adjust the width.. by about 5 cm over the entire range of the coil, so the adjustment is very subtle. They are only used to compensate for slight variances in the yokes and tubes, normally they don't need setting unless you've changed out the tubes.
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faidros
Joined: 16 Jul 2010
Posts: 2
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| Posted: Sat Jul 17, 2010 7:07 am Post subject: |
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Dear Mr Palme.
I am aware of that this is a more "unusual" adjustment. If not for other reason the risk of destroying the coils with magnetic screwdrivers.
It was a attempt to adjust more "internally" then in the menu. In order to keep most control nearest possible midrange. When I started on this road I noticed that the raster were way out of the tube edge. I belive this is not critic as long the projected image is kept well on inside of phosphor. That seams to be the consensus though.
But if this is right, then the raster should be made to cover the entire phosphor, and we should all concentrate on the image.
And since there is a lot discussion regarding the raster it got me thinking that my assumption might be wrong - that the raster need to be correct adjusted.
And it was at the end of this ide that I start playing with the raster width coils. I was trying to get the raster smaller then the phosphor. I was able to do this only in the menu with "raster size" and setting at 0 - 4.
And when the raster did not alter size at all no matter how I adjusted, it got me thinking that it might be a symptom of some other problems which need addressing  Or just plainly for understanding the relationship coils - size.
For order sake; p2 is adjusted correctly at 48v
Regards Olav
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Ile
Joined: 09 Mar 2006
Posts: 1491
Location: Jyväskylä, Finland
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| Posted: Sat Jul 17, 2010 8:03 pm Post subject: |
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Coils are good for matching horizontal linearity between tubes, but for Hwidth use menu. It's better to have it near 100 than 50...
If menu don't have enough adjustment range, set menu to 95 with highest resolution and adjust with P2 to fill the faceplate.
About raster size:
Your sources porch settings determines raster/picture relationship, you can't adjust that in projector. You just can adjust raster width that also effects to actual picture width inside raster. With high resolutions horizontal porch settings (blank pixels before/after actual picture) need to be quite high, that makes raster too wide for tubes face plate.
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