CurtPalme.com Home Theater Forum

[zGman]

frt centering clamp is co-axial, ie not for beam centering, just physical.

[Chuchuf]

[garyfritz]

Well hopefully the KD22-11's do almost as well!

[zGman]

Greetings,
Another thing I spent a lot of time on was adjusting the convergence yokes
so that the axis of adjustment coincided with the V-H axis on the screen, eg
so that there was no diagonal movement during convergence adjustments - maybe the wrong
thread, but I would like to ask if there are others who have noticed any correlation
between "banding" and stability and making this somewhat tedious adjustment???
Older Marquee's just used hot glue between the deflection and convergence yokes -
later models seem to have "superglue" locking them together - thus making
the process of freeing up the adjustment somewhat nerve-wracking....hohohoho!
Thanks,
Galen

[cmjohnson]

At the factory, the convergence yoke is hot-melt glued to the deflection yoke after the alignment is done. There's a certain degree of
built-in rotational adjustment between the two yokes. Any time any yokes or the tubes are changed, it may be necessary to remove
the hot melt glue and readjust the convergence yoke.

Always make sure the convergence adjustments work properly. Sideways adjustments should not move vertically, or vice versa. It's probably the single simplest adjustment you can make on a Marquee's magnetics, and as the voltages on the convergence yoke are very
low, only about 20 volts at most, this is an adjustment that doesn't present its own safety issues. But be careful of that nearby deflection
yoke and its exposed pins!


CJ

[zGman]

Hi Chris,

When you get into the late model Ultra's (my two are 2002/3), you will discover that the conv yokes are
actually "superglued" to the deflection yokes, not too easy to separate! The glue is actually internal
to the mechanical joint, and not an externally applied bead as on the earlier models....

But yes, considerable care should be taken adjusting while running - personally, when too much effort
was required I depowered the set. My feeling was that the adjustment would reduce the load on the
conv board and possibly reduce the chance of "banding". etc.....

G

[garyfritz]

[1031]

[cmjohnson]

If the focus isn't sharpest near the optimal adjustment range of 40 to 60, then most likely the field strength of the permanent
magnets in the focus yoke isn't optimal. Tse has the ability to readjust the magnet strength of Thomson yokes but I don't know
if he's able to do this on the K-D yokes. Nor am I suggesting that you ask him to do that. In fact, I would ask you NOT to ask
him for that as he doesn't OWN the magnetizing jig. He just works there. Perhaps a deal can be worked out, in time, which
allows you to send your yokes to VDC for magnetic optimization for a REASONABLE cost.


CJ

[garyfritz]

Hm. So at least for this coil I've tested, the magnets are not the right strength for the tube, so it is not usable without re-magnetization? That's a major bummer.

I assume if it doesn't work with the red, it won't work with the other tubes either? So it's not worth the hassle to test this coil on the B & G?

I will go ahead and test the other coils. If for some reason one is bad but the others work OK, would it be reasonable to e.g. use KF2211's on R & G, and use Thompson on B where focus is less critical? Or is it a bad idea to mix coils?

[zGman]

Hi Gary,
There's a big difference between "not optimal" and 'won't work'.....!
One thing you may want to bear in mind is that the focus is
extremely dependant on the cpc magnet setup.....
and if you have an 8000, then that's really all you have
to work with to control flare/stig....
I would encourage you not to give up just yet...
Cheers,
Galen

[tse]

[garyfritz]

[garyfritz]

OK, I finally got the other KF2211's installed, but I'm not sure this is going to work.

I reset the projector (I have a new CLM in it anyway) and made sure all the CPC rings were neutralized. All three focus coils are butted up against the front yoke.

* As I mentioned, I put the red in before. FOCUS has very little effect on this color. Sweeping FOCUS from 0 to 100 makes a noticeable change, but just barely. I had to set the Red Focus to 100 to focus the red with FOCUS at 68. I can't get a sharp focus with FOCUS at 50.

* The green is dramatically different. It gets hugely affected by FOCUS, more like I would expect. (Except there is some raster distortion as you sweep FOCUS -- the vertical lines don't stay quite straight. Not sure if that's normal. The raster also moves left-to-right a fair amount as I sweep FOCUS.) With the FOCUS at 68, the focus is sharpest with Green Focus at 32 or so. So the green would probably focus just fine with FOCUS = 50 and Green Focus = 50 or so.

* I must have a bad connection in the blue yoke, or a bad coil. Blue is out of focus and FOCUS doesn't affect it at all.

The R and G yokes are identical -- the ones with the "+10" sticker on them.

If all 3 colors worked like the G, I'd be in good shape. But the R doesn't seem to be affected much by focus adjustments, and the B isn't working yet. The R is nicely centered, but the B and G rasters are off to the left slightly. And, of course, I don't have any Thompson centering adjustment. I can improve the G centering a bit by rotating the coil about 180°, so the wire/socket is on the bottom, but it's still not perfect. Maybe half a square off in the RGB Focus pattern. Blue is about the same. I assume I should be able to correct this with the convergence adjustments, though that's not ideal.

Any ideas why the R acts so differently from the G? If I could get the R working like the G, and fix the B, then maybe this would work. Maybe it will work OK with the R not focusing much, but...

Gary

[tse]

It's alot of work but try each of the mags on the green tube and see if the mags are different or if the projector color circuits/wiring are causing the different responses.

Scott

[Nashou66]

Well I got word back in late november from the coil winding place just before i left for my trip here to Greece. they said the magnets they can not do but they can rewind the coils . but i they want an engineering fee of about 250-500 to set up and test the wind and they said this is the standard one time fee. i havnt thought of it much except for the last few days. But if enough people want to have thier coild re-wound to the correct specs and maybe TSE can work out a deal with VDC to use the magnet gauser at his work we can still use the barco focus magnets . Or maybe there is a way to magnetize them in the manner that Chris Johnson did with the CPC magnets? The latter would take alot of trial and error with magnetizing each ring and then putting it all back together for testing, ect.

TSE are you able to use that deivice at work?

Athanasios

[tse]

Bad news about the magnets. That would have been a good thing. Winding the bobbins should not be a big deal. Any transformer, motor rewinding type place should have no trouble rewinding the coils. You can do it by hand if you can rig up some kind of hand crank device. The magnets are the right gauss if you put them on the tube without the wires connected and the tube is close to focus. Leave the CPC mags off for this test.

Scott

[Nashou66]

I think i have a test pattern showing the focus of the magnets alone somewhere, i'll post back and let me know if it is adequate. also on the winding of the coils, does it really matter for each wind to be perfectly right next to each other row after row or can they kinda be randomly wound as long as you keep the wind even across the bobbin with no major high or low spots? I wound the one to 30mh but never had a chance to test it as i was in the process of sending them to the winding place.
ok found the link to my first test of just magnets.




Athanasios

[tse]

That focus looks good enough. A little current through the static winding should bring it in. The windings don't have to be real neat. Though if they are too rough it might be hard to get enough turns on to the bobbin.

Scott

[Nashou66]

thanks Scott i'll have them send back the focus packs and try it myself.

Athanasios