CurtPalme.com Home Theater Forum

[PaulB]

Ok, been going through the magnetic setup on my Marquee (all magnetics are stock, 2 pole only). Never touched magnets before and have avoided doing so ever since I started using a crt many years ago but its unfortunately a necessary evil for a proper setup. Magnetics have also been a weak spot for me, don't fully understand them and don't want to touch them - bad way to start!

I get the general idea of getting round dots with a bright center and have read up as much as I can find on the matter and am using Bill Blues superb Magnetics 101 but boy oh boy, am I finding it difficult or what!!

Strangely (or maybe not so strangely as its the best/newest tube), red seems to be easiest. I can get the dots pretty much as they should initially but always seem to end up fighting the focus coil and never quite get to where I'm supposed to be. Green proves to be elusive, I can get round dots but can't see the bright centers (I'm assuming that they are off to one side or other). Blue is so bad I've left that alone until I can deal with the other tubes (more difficult to deal with the blue I know).

Looking into the tubeface on the red, I can just about make out the top two squares in the SMPTE RES01 1920x1080 pattern (despite the fact that the magnets and coil are no where near 100% correct so I'm fairly comfortable that its my total inability to get a good magnetic setup thats the problem rather than any other problems maybe) - this was my best effort so far but I can still see flare etc on text so its nowhere near decent never mind perfect. This was done using RGB focus at 100 but I don't think it should be that high (PIC focus was around 54 or so)?

My failure to easily get 1920x1080 fully resolved has me questioning myself, namely am I fooling myself that I should be able to resolve this pattern fully without a fully modded VIM? Maybe I'm aiming too high and should start at a lower res?

On a related note, I find that my Marquee blurs (for lack of a better word) at contrast levels of about 60 upwards, from what I can find, this is normal yes(?) or is this also a side-effect of bad magnetics? (pretty sure it is bad mags as I'm positive I didn't see this quite as bad before I started touching the magnets a few days ago). I suspect my efforts have made things a lot worse than from where I started, in fact, I'm sure of it. Also, when having only one tube lit up, ramping up the contrast as required to do the magnetics, at about 55 contrast the other tubes start to light up as well, normal?

I'm at the stage of having regretted touching the magnets but you can't get the best out of any pj without some pain somewhere along the line but I feel like I'm in way over my head here. Is it really this hard to get the magnets right? Everything else is easy compared to this!

I've attached an SMPTE RES picture taken by Tse that shows what the top two boxes should look like when resolving 1920x1080, mine generally just end up looking blank?! Maybe I'm simply not trying hard enough or expecting too much on the few hours I've spent on them?

Thanks guys,
Paul

[1031]

http://www.curtpalme.com/forum/viewtopic.php?p=115212#115212
Trye if that pattern makes adjustment easyer. That marquee magnetics 101 procedure is quite hard at first time.. So you must practise it few times. One thing you must look is that raster (rasters) doesent move at any direction when you adjust focus. If raster moves, you must redo centering with focuscoil and also 2-pole (and maybe 4-pole, if needed)
On that pattern i posted that circle in center helps you to see how flare is around circle.
And yes, bad magnet setup makes picture blurr at lower contrast levels.

[PaulB]

[Nashou66]

Paul I still have not mastered Mine either. I still get movement while adjusting focus and I also know I can do better. read this also, Generic CRT alignment and focus set up.

I still plan on redoing mine as well.

Athanasios

[Elaine Benes]

Funny, in the past, I've been derided and ignored for saying magnetics is very, very, very difficult to get right and to avoid moving the factory set magnetics if you already have good focus...

[garyfritz]

PaulB, are you adjusting the focus as the procedure says? It's critical to set the focus to 100 to get the round blobs, **then set focus to 0** to see the bright spot inside the blobs. All with CONTRAST = 100.

I generally set my magnetics using the crosshatch pattern instead of dots. I can see (from the projector) the bright line inside the fat crosshatch lines much easier than I can see the bright spot inside the blobs.

[draganm]

[garyfritz]

Right, but the position (e.g. location of a crosshair) shouldn't change if you have the magnetics nailed.

Leaky caps cause blooming at high contrast, eh? I replaced those caps on my VNBs but I haven't looked to see if the high-contrast blooming was improved. Have to look at that.

[PaulB]

Lots of good stuff here so I'll try and answer it all;

Athanasios - I would have bet money that you had nailed your focus good and tight, you've surprised me! At least I'm in good company Thanks for the excellent link, will be looking at that in more detail. (I've stopped modding now but am collecting the necessary parts).

Elaine Benes - I think that is good advice BUT I also think good magnetic setup can mean the difference between a reasonable pq and a great pq..... but is it a risk worth taking given what I've just been through and have yet to go through??? I'd say its worth the risk but would also say if you have the cash, get a pro to do it!

Gary - I've been defocusing to get the blobs with bright centers then 100% focusing to check circularity. This is the opposite to what you have said but I suppose the end result is the same (?). Thanks for the info about a Cross-Hair pattern, again I can see the usefulness of a central marker as opposed to dots. I try that along with Jarmo's pattern

Dragamn - New caps already on the neckboards ( 33uf 160v 105degree Caps at C1 and C26 ). Thats good about the contrast ramping/ blurring, after Athanasios's dire warning to me last week about not having tested my mods I was dreading the idea that I may have screwed up something! Its ironic, i did manage to get the rasters steady a couple of times but the focus was just awful (at least awful in the sense that I wasn't getting the results I thought I should be getting).

Well, its good to see that its just not me that finds the magnetics difficult, no, strike that, bloody difficult!! I'm relieved that its not some underlying problem (could yet turn out to be I suppose) and that others, including some of the "old sweats" around here, find the magnets well, lets say challanging. I think I expected too much of my own abilities and it speaks volumes about those who are truely able to produce such incredible focusing results with ease.

I think it was CZEddie or CMjohnson who wrote that they could now do a complete magnets job on a marquee in only a few hours - gentleman, I take my hat off to you. I never realised that such a high degree of skill was needed to acheive such a seemingly simple task!

Frankenyokes! Don't have 'em but now on the 'must have' list.

[JustGreg]

Paul I anguish right along with you. I avoided sticking my hands near the magnetics like the plague for the longest time.

I've had my Marquee 8500 (non LC) for two years or so and have only done a full magnetics once when it was floor mounted. THAT'S how much I enjoyed it. Of course, that ONCE lasted three days. I experimented with low power el cheapo binocs from Walgreens (a pharmacy chain) so I could see the screen from the pj and then evolved up to a tripod mounted DV cam set for nightshot set close to the screen.

It's held steady for all this time BUT...and a big but..my raster width is horrible due to room constraints and my own laziness. I'm putting a hurtin' on my tubes by not maximizing. That and I'm not getting all the light out of it I should be, which is VERY evident in dark scenes. (I have no add-on gamma gizmos to compensate).

But...I have a spare set of (visibly) 9+ tubes, PS's and all but the convergence boards and a CLM, which MP has so for now I just muddle along.

And you're right, there's some great info in this thread. I'll have to have another go at it once I finish building out the outside areas of my HT.

[Tim in Phoenix]

Hello


I wrote this http://www.etechvideo.com/techtip9.htm for people like yourself, see if the explanation is clearer.

.

[Person99]

[Elaine Benes]

So, I've been forced to do the magnetics too...

When you're doing it, should you be worried about the focus not being correct for all three tubes when the global "Focus" control is at 50 ?

Red needs focus to be at about 30 whereas blue and green are pretty close at 50 using the global focus control.

Also, is "round" really the ideal shape of the bright blob in the center ? I get a sharper output when I just make sure there are no stray flares emanating from the bright blob. I can make it round, but when its round the focus isn't as good....

[garyfritz]

That's what the RGB Focus is for. Adjust each color so it's sharpest when the global Focus control is at 50.

Stray flares? Can you sketch an approximation of what that looks like? I get no flares on mine.

[Joust]

[PaulB]

Oh Bugger!! Just when things were starting to look good.

I've lost all control over stigmator for the Red tube ( Utils <password> 7 )

It was working fine until today. I got a good blob using focus coil etc, went to use the sigmator and the bloody blobs didn't change shape. Tried the green tube, fine. Tried blue tube, fine. Hmmmm. Swapped the cables of the red and green on the Stigmator board and found that Green then stopped moving but red also didn't appear to move BUT when I saved the settings and went back to look at the red the blobs had changed shape!!? Swapped cables back, green moves as it should, red doesn't move at all.

Pulled the CLM and had a look but nothing obviously wrong with the Stig board and can't see anything up with the stig board on the heatsink? Had a look at the focus coil (didn't take it off, just examined it as best I could), nothing to see there.

This was going so well upto that point, that SMPTE pattern was looking very nice on the red (only done the red so far). Those different pattersn really helped plus I think I'm getting the hang of it (barely, but I'm improving).

HELP. Any idea guys??

Thanks,
Paul

[Person99]

[Nashou66]

This could be good news, you may have the astig done so well on the cpc magnets it doesnt need any electronic astig adjustments? I don't have mine connected since who ever re-tubed my PJ took the good coils with astig windings .

Anyone else know if this could be the case?

Athanasios

[Elaine Benes]

Check the blue rectangular thingy's standing up on the stig processor board on the CLM. I've seen these burned out LOTS of times...

[PaulB]

Well it was worth a try.

Elaine - I checked the blue things on the board but they all look fine (as does all other components).
Sounds like you are doing ok with your magnets, just take your time and maybe leave it for a day and then revisit them. Sometimes giving your brain a rest allows you to think through the magnets a bit better rather than getting frustrated by not getting it right in one go. Your questions were the same ones I was asking myself a day or two ago - you're going up the learning curve .....!


Athanasios - just un-done my good work to check if your theory was correct. Unfortunately it didn't work, i thought you'd solved it there but that would have been too simple a solution I suppose.
Sorry to hear of your own issues, bloody nightmare trying to track these sorts of things down. Theres nothing loose like a wire or something thats shorting out the picture momentarily is there, an earth wire or something maybe thats just barely connected? Just guessing.

Tried reseating the CLM but to no avail. All the chips on the CLM look to be well socketed, I checked them a couple of days ago after the railroad error on the LED's.


Arrrrghhhh! Not good.