CurtPalme.com Home Theater Forum

[backslap]

Hi there,

I'm looking to do the Marquee Magnetics Setup 101 (by Bill Blue) (http://www.curtpalme.com/docs/MARQUEE%20MAGNETICS%20SETUP%20101%20by%20Bill%20Blue.pdf with my PJ mounted on the ceiling.

Step 1 is to remove the lenses in order to center the crosshatch, but my Marquee has HD-144 lenses which are mounted in a way that they can easily be romoved when the PJ is on the floor, but impossible when it is on the ceiling, according to the previous owner.

So, taking into account that I can't get the lenses off, is it any use to do the magnetics setup by just looking through the lenses to determine the center? Or do I better just leave it alone?


Grtx, Elwin

[Sparky015]

Do you have a pic of the mounts your 144s are on? If they are on JoustMods (see the product page on Curt' s site for a pic of what they look like), they can easily be removed on the floor and in the air by just removing the 4 black allen screws per lens. Should take you 10-15 minutes max. I just can't understand why it would be easy on the floor and hard in the air. The Marquee is nice that way. you can do most things to it in the air, lens removal being one of them.

If this is a new projector for you, I would encourage doing the magnetics setup. It may or may not have been done before and it's a great learning experience getting to know the machine.

EDIT: The 4 SMALL allen screws, not the large ones! with two of them covered by red caps!

[Nashou66]

One thing to be careful of is the Deflection coil exposed pins where the wires are soldered to, those have lots of voltage up to 1000 volts, usually they are covered but i found to do the magnetics correctly and get your hand around the focus coil to be able to move the grid around you need to remove the metal covers on the tubes as well exposing those deflection pins.

Also before you start null the convergence by going into the convergence menu and hitting "0" while in any of the convergence choices. this will let you kow if all your deflection coils are level. if not you need to straighten those as well.

here is some more reading you should do.

http://www.etechvideo.com/techtip9.htm

http://www.etechvideo.com/techtip10.htm

Athanasios

[backslap]

Hey guys,

I've managed to get the green to center at least OK with the lenses on. The lens mounts are custom on this machine making it hard to get the lenses off in the air.

I have a question about the C Linearity: With the green tube centered pretty nicely, I still have to set the Horizontal C Linearity all the way to '15' to get the squares to be the same size on both sides! Am I missing something, or is there no mechanical fix for this? It seems like a big adjustment to me!

PS. I am doing the setup by Bill Blue's 101 mechanicals as well as by E-Tech's tech tips, they're both great!

[Nashou66]

On some machines it is needed on others it is not, both my longbows need massive linearity adjustments like yours.

Athanasios

[backslap]

Alright, so I'm doing the procedure right now. I'm adjusting focus with the CPC and Stigmator and Convergence Yoke. I've got lovely ROUND blobs on focus 0 and focus 100, but the raster shifts then I go through focus by 2" on screen... How do I correct this?

[Nashou66]

[backslap]

1) How do I disconnect the Astig?

2) Keeping the raster centered + round dots at 0 focus + round dots at 100 focus + no movement of raster seems impossible! Especially since the dots are already nice and round and the lines centered inside the dots... How do I do it?

3) Before I started it was like yours, maybe 1/2" movement of the raster, so that was very good. But the raster was far from centered... Do you think it's possile to get both right?

[Nashou66]

Yes it is but you have to go back and forth between adjustments. takes patience, and time. I worry about the dot roundness last, try to get the centering CPC magnet and the focus coils adjustment so the grids do not move. So you should start with Nulled CPC magnets, the only real way to know if they are nulled is to take them out and put all the tabs together, then put them back on the tube and have the knobs all facing up. the first ring is the centering ring. use the focus first to center the raster, lok it down so it doesnt move, then look at the dots , use the centering ring to center the bright dot. now move grid back to center with focus coil, lock it down. now check bright dot again, is it still centered? NO!? Oh man!!! Center it with the centering ring, now if the grid moved off center center it again with focus coil, lock it, check bright dot, is it centered? ... etc...etc...etc...

oh just unplug the astig connectors form the SAB board on the rear heat sink, not the VDM !!! i think the wires are purple and white.

Athanasios

[backslap]

Well I started out with nulled CPC's like Bill Blue says to do. Just put them rotated so the raster had as little movement as possible from sliding them back and forth..

I will try some more!

[Nashou66]

[csamos]

Athanasios has great advice here. The main thing is to have patience. It can take a lot of adjusting back and forth to nail it down nicely. It took a long time for me the first time I did mine from scratch. And each time I've done it, I've gotten better and faster. I found that the better I get mine, the less I need to touch up convergence or anything else, and I have a nearly perfect grid pattern with no banding. I'm about to replace my blue tube, so I'll get to do this again, too.

-Carl
http://www.samos.org/Theater/

[backslap]

Hey dudes,

I know, I'll try some more... The thing is, it doesn't seem to be getting any better... I would have thought that I would at least see some improvement... You guys don't think that the reason I'm not improving could be that the convergence yoke is just at some far point where it can't be adjusted properly?

Grtx Elwin

[cmjohnson]

Here's a tip for getting your linearity adjustments right: Hook up your PC and draw up a simple test pattern which consists of a single X from corner to corner, with an outlined edge.

Only when the linearity is right will the lines of the X be perfectly straight. And when those lines are perfectly straight and the outer box
is perfectly rectangular and in the right proportions, your on-screen geometry is perfect.

Any variation will cause the X lines to be bent or curved.

It is the simplest, yet most overlooked, of all test patterns.


CJ

[backslap]

That sounds like a good tip! Does it have to be 31KHz?

But still: The thing is, it doesn't seem to be getting any better... I would have thought that I would at least see some improvement... You guys don't think that the reason I'm not improving could be that the convergence yoke is just at some far point where it can't be adjusted properly?

[Nashou66]

it just takes time and lots of practice. Are you sure your moving the main focus coil too? the one with the brass wing nuts?

Athanasios

[backslap]

Yes, I am trying different settings from the focus coil, then fiddeling around with the 2-pole magnet... I've been at it for a while now but I just can't seem to get any improvement whatsoever, in whatever setting! It's driving me nuts!

The only way I've been able to get the grid not to move when I go from 0 focus to 100 is by setting the raster to the upper-right off center (on screen) for about 3"....

[Nashou66]

[backslap]

Yes, I am moving the entire coil around. I will try to also undo the focus coil's outer hex nut so I can rotate it.

But what I'm seeing is that when I get the grid centered AND the blobs nice and round (sounds good so far, doesn't it?), when I ramp up the focus, the whole grid moves around terribly, just to display nice and round dots at 100 focus again...

I only have a manual 2-pole and a dummy ring BTW, Stigmator adjust is in the Util menu. (Marquee 8500 Ultra, 2001)

Also, when I started out the focus did hardly anything to the grid (so that was nicely adjusted), but the grid was about 3 to 4" off center...

[Nashou66]

Hmm My 2004 8500 ultras have 6 pole and the electronic astig, Must have been the custom order for the LongBow designation. Are you sure the other knob is a dummy magnet?

Well keep at it, take breaks every once in a while to collet yourself. Think about the effect on the screen when you move the coil, sometimes it helps to visualize what to do. So now say when you ramp focus the grid moves to the left, hmm what if i move the dot to the right first , then move the focus coil then look at the dot, did it go towards the center more? Things like that, remember things work a little backwards when looking at the screen so you brain can get twisted

Athanasios