CurtPalme.com Home Theater Forum

[cmjohnson]

This is something I've seen on a number of Marquees. Incorrect convergence timing. You can converge the
picture but convergence isn't actually working correctly, which can introduce small errors into the total converged
picture that you can't iron out.


Here's a quick chart I made up showing some examples.






What you need to know here is that the convergence coil's signals have to be properly synchronized to the deflection
signal, and timed exactly right for them to work on the correct part of the picture.


This diagram shows correct timing, incorrect timing, and correct timing combined with undesired rotation of the convergence yoke.



Check your Marquee to see if your convergence is operating correctly. Bring up the green convergence screen via the UTIL menu, (code 0901 to access the green convergence menu) and move the cursor to any spot on the grid OTHER than the center. Hit the enter key to switch from MOVE to CONV and then use the directional arrows to introduce a maximum movement of the selected cross in the vertical direction.

If the result of this move looks like the first diagram, you don't need to make any adjustments. Exit and be happy.

If the result of this move looks like the second diagram, your convergence timing is off and you may opt to adjust
the timing, which is an option that is not particularly user-friendly and is well hidden in the factory service menu.
How this is actually accessed and utilized will be left for a follow-up post. If you need to do this adjustment,
you will need to PM me for the access code to the factory service menu. I won't give it out on the board as there
are adjustments in there that can render your PJ inoperative to the point that you'd have to send the CLM back to
VDC for resetting. Seriously. There are useful adjustments in the factory menus but it is not a place for everybody.

If you already know how to get into those menus, the menu items in question are located in the sub-menu called "Adjust start pulses". There are four different bands to adjust, each with their own menu option. These bands are the range of horizontal frequencies that the adjustments work in. They correlate with the internal scan frequencies that you can select in the setup menu.

Band 1 correlates to internal frequency 1, at 15 KHz.
Band 2 correlates to internal frequency 2, at 31.4 KHz.
Band 3 correlates to internal frequency 3, 4, and 5, at 47, 62, and 89 KHz.
Band 4 correlates to internal frequency band 6, at 120 KHz.

You don't need to adjust in bands you don't use.


If the results of this test move look like the third diagram, you have a rotated convergence yoke. You will need to rotate it a little in the appropriate direction and eliminate the cross-axis component from the convergence movement before you know if the timing is actually correct or not.

But, be aware that adjusting the convergence yoke requires access to the tube magnetics while the projector is turned
on. There are high voltages present, and at high frequencies, and this is not a procedure to be taken lightly. If you
are not comfortable working on tube magnetics on a live projector, DON'T DO IT. This is an ADVANCED procedure
to be done by ADVANCED users only!

There are pins on the deflection yoke that typically carry 1500 volts on them at the horizontal scan frequency currently
in use. I've been hit by that. It's not a shock so much as it is an instant BURN. Burn on the order of "jab sharp
hot soldering iron tip into your finger" level of burn. Nasty and painful and slow to heal.

Be aware, also, that on most Marquee tube assemblies, the convergence yoke is hot-melt glued to the deflection yoke
and you will need to carefully separate the glue before you can make any adjustment to the relative rotation of
the convergence yoke. THAT should be done with the projector turned OFF.


There are also similar timing adjustments for the stigmators and for focus as well. Once you know how to do
the convergence timing adjustment, you will be able to figure out the other timing adjustments pretty easily.


If you have a Marquee that just won't focus right, or you can't get one side of the screen to focus as well as the other,
the timing may well be off. Same applies to stigmator operation


CJ

[Nashou66]

Nice info Chris, one question can the Horizontal adjustment be out of timing like in your second diagram ?

i have a few spots on my Longbows that just do not want to straighten out, in both horizontal and vertical. And for a blend you need to get that perfect.
I have not checked the timings but i might decide to.

I'm book marking this thread.

Athanasios

[cmjohnson]

The convergence timing applies only to timing referenced to H. deflection. If there is a horizontal component to a vertical convergence move, it will be a rotation issue with the convergence coil.

Actually, let me rephrase that: Horizontal and vertical timing both are set within the convergence band you select. But the adjustment
is for horizontal. The vertical timing is preset and derived from the band setting. You don't have to worry about it and can't individually
adjust it.

I'm getting ready to pull my 9500 down and give it the full five year rebuild. It was five years ago that I rebuilt it, converted it to a 9500,
put in brand new tubes, and did some mods to it. But I have slow leaks in the coolant chambers on two tubes and will be getting
a set of your new bellows for it, and putting on HD10Fs, and recapping a bunch of boards, and doing some other things, too. It will
be quite the machine when I'm done, among the best 9500s running.

I'm also building a jig that allows me to take any old pair of 2 or 4 pole magnets and remagnetize them as 6 pole astig magnets,
using either N40 grade permanent magnets or a cluster of electromagnets in a clamshell fixture. If it works as well as intended, then
for a nominal fee I'll be able to do this for other people. I'd recommend that anyone should save ALL their old CPC packs because
I can turn three flare only packs into one 2/4/6 pole pack....or I should be able to.

CJ

[garyfritz]

Cool stuff, Chris. Is there one timing signal for all 3 colors, or do you need to repeat the test on R & B?

[Nashou66]

Gary, id assume its just the greens, on my Ultras if i do a green convergence the red and blue follow it when i am done. On my older marquee's this was not the case , so maybe on certain software equipped marquee's you would need to. Chris?

nashou

[cmjohnson]

The convergence timing settings are global within their frequency band. All colors are adjusted at the same time with these adjustments.
I did the illustration in green as it reflects my personal preference of doing all master adjustments in green and then adjusting red and blue to match. It's easier to see what's going on with just one CRT running.


I believe that you are correct. Green master adjustments are automatically followed by red and blue if the PJ's
firmware is above a certain revision. I'm using version 3.4 on my machine and red and blue do follow any green
master adjustments on it. But version 2 ( the earliest I've seen on an x500) didn't do that, IIRC.



CJ

[mp20748]

.. or you could deal with it another way.........oops, I forgot I'm not supposed to go into that menu..

[cmjohnson]

Thanks for reminding me of that one, Mike!

That's related but doesn't do quite the same thing. All this does is center the grids on the screen. Useful,
but different from convergence delay in a fundamental way.

The convergence delay needs to be set as well as the centering.

Depending on the firmware revision, there are a lot of secrets hidden in the menus. General tip: Just because the menu options don't
list a specific number in the list, doesn't mean pressing that number won't bring something up.




CJ

[Nashou66]

I checked my one long bow with the internal grid and it is off, I get the arch peak about 1 inch from the vertical line. I think I might actually want the secret code
Chris. I also checked at the 8 zones t,b.l.r.and all corners and its on all locations. So do you adjust one location and it alters them all or do you need to got through and skew each zone and adjust it there? Also what is the process like?

And what does the one Mike show do?

Athanasios

[PiDD]

Great post. Mine was off just like the second pic. I adjusted down to 40 and that was too much to the left. 46 seems to put it back in the middle.

thanks for sharing... anything else out there you want to tell us about?

[J Kildare]

Chris,
Thanks for the great info!!
Could you please PM me the code..... Mine is exact match to #2 and off by a little more than an 1".

Also, what are the side effects of the menu MP brought up if it's adjusted incorrectly?

My static convergence has never been as stable as I feel it should be (dynamic is very good) and I have always felt that something in the ultra secret menu is the problem. All boards have been capped @ 105 deg and all boards swapped and still no love.

Thanks
Jim

[cmjohnson]

I've taken a bunch of photos of almost the entire process. I've still got to edit them and compile them into a guide of sorts, but it will probably be a couple of days before it's done. I'm not the fastest guy in the world at things like that.


There are also timing menus for focus, contrast modulation, and stigmators. And I will tell you, ALL of those have a direct bearing on
the overall quality of focus you will get out of your Marquee. If you're not getting razor sharp grid lines, I would suggest you run through
all of those procedures, one at a time, slowly and carefully, and then if you're still not getting the razor sharp performance you should,
check your magnetics (CPC rings in particular) and then if it's still not razor sharp, consider sending in some of your boards to Draganm
for overhaul.


CJ

[Nashou66]

When you drew that image chris is the grid pint sharp like that? the Apex? mine is not sharp to a point its more rounded at the top but over to one side an inch also.

Athanasios

[cmjohnson]

It apparenly depends on what scan rate you're using. Set the scan rate to 15 KHz and you'll see fairly angular convergence curves.
Set the scan rate to 126 KHz and you see smooth curves.

However, that's what you see when you bend a line up or down. At any scan rate, when you bend a vertical line side to side, the bend
is angular, not rounded at all.


CJ

[J Kildare]

Awesome Chris, mine was factory set at 50 and off by over an inch. It is now set at 46 and looks much better.

I also am doing some mods to my 9500, I installed frankenyokes (thanks for that also) and also a set of 2 pole magnets in front of them for raster centering ( I will look for the post if you want, I think it was by 1031 ), anyhow I left the front cover off the frankenyokes and hot glued the magnet in all the way around. If I ever need to sell them or put the front covers on it's just a matter of pulling off the hot glue which should come off easy, but still holds the magnet in nice and firm.

Nash, it kind of looks like a very subtle top half of a sine wave if your running in band 3.

Jim

[WTS]

I wonder, do the BArcos have this type of adjustment.

[cmjohnson]

My guess is that any digital chassis HAS to have this sort adjustment as there must be a way to time the convergence pulses to match the
desired position on the screen. At different scan rates, that timing must necessarily be different.


But is that ajustment available in a hidden menu or is it programmed via a PC connected to the serial port and running specific software? I can't even guess, not on a Barco.


CJ

[Nashou66]

Just altered mine as well and straightened out a few spots i could not get before. thanks Chris for the info!!!.

Athanasios

[WTS]

I've never seen(in my Barco) a menu where it asks for any passwords etc before it will allow access to special adjustments, so maybe the Barcos don't have this function.

[cmjohnson]

I would be speculating if I gave ANY answer to that. The only Barcos I've ever played with that worked are 3 chip DLP units. Very much a different breed.

Maybe Curt knows? Or Mike?


CJ