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Discussion Starter · #1 ·
Well, I decided I couldn't leave well enough alone. Sound familiar? I decided to start from scratch, do a full setup, and try to implement Guy Kuo's focus procedure. (Even got out my binoculours :))I had been using too much (IMO) electronic convergence, as it was way off at start up, and would drift "right" as it heated up.


So, I perform a reset, zero everything out. Set raster. Do video chain alingment. Begin focus. I get through the flare/stig rings, and I must say...after the past 4 hours, this thing has never looked this good...at least with an unconverged Windows desktop.


Now, the point I always get stuck and good good old electronics help me out. The red and blue are about 2-3" out of convergence vertically. It's obviously pretty easy to mechanically align them horizontally, but I am unsure what to do here. There are no centering rings on the ECP (at least not on my 4000) so I don't know how to proceed and align this thing. Can someone help? I've got both the service manual and setup manual, and neither of them seem to address this. At least I can't seem to find anything right now. It's almost like there should be a vertical position for red & blue.


On another topic, M NEWMAN, if you read this, you told me once that the space between the CRT and the back of the lens should be on the money 1". The manual calls for .6 +- a bit. Is 1" a better measurement and the .6 is a factory less than optimum measurement?


Thanks guys!
 

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Yo Jay!


I think that you're supposed to take care of the vertical alignment with the convergence coils. Mine seems to drift much less in the vertical direction anyway so this isn't much of a problem. You *might* be able to get some mechanical movement by loosening up that whole top plate (like you do when you're replaceing the tubes). I haven't tried that so I don't know.


I also saw Mike's post about the 1" and that's where mine are set at. However, I just checked my 4500 service manual and it's pretty sad - it just says to make sure that (after you've replaced a tube) the distance approximately matches the other tubes! Duh!


If I brought the lens mounting plate in a bit from 1" I wonder if I could fix the problem where I can't get enough range out of the H size control to get both 16:9 and 4:3 aspect ratios (ie. would getting the lens closer to the CRT change the throw distance?).


How did the focusing work out Jay?


Cary
 

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Discussion Starter · #3 ·
Convergence coils...Hmmm....I didn't see a reference to those. It would makae sense. Basically I need the red down about 3" and the blue up 2". I thought about the top plate and did at least confirm that all 3 tubes are "locked in." In other words, they are all on the little pins. I wanted to make certain that it wasn't something stupid causing it to be off.


Focusing looks great. Just like everyone said it would :) It's a b***h though. Halfway through you want to say "that looks good" but you persevere and check, double check, triple check, and once more for good measure. In the end the extra time spent seems to have paid off. Mechanically, I don't think this thing has ever looked this sharp. I don't have a pic to compare yet (no convergence :() but I really think it will live up to expectations.


On the .6 vs 1" spacing...I also have a bit of a problem in that I have to nearly max (9 out of 10) my sizing controls to fill the 16:9 screen. I used Mike's 1.5 x width formula for throw distance. The (less than) 1/2 inch it would take to bring the lens closer shouldn't change the throw distance, but it would change the image size (some?) and that may help with the sizing controls. My manual is for the Vidikron manual, and so far the only thing that appears to be different is the software. Convergence controls are a different (slightly) procedure than the Ehome. I don't think the lense would be different to cause a different mounting space.


BTW Cary, All measurements so far coming out nicely! Thanks for the loan of the extender card and the scope instructions!
 

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Hi Jay, wow. Once again you're raising "ECP bar" and you're going to make me do this focus procedure. :)


Sorry about the convergence coils, I should have just said "use convergence".


If moving the lens back buys me a little more screen width, I think that will help me. I can keep my 16:9 maxed at 10, move the lens back to make it wider so it will overscan my screen. Then adjust the raster width on the Power Deflection Board so it fits my screen, then hope that 4:3 is correct now when I shrink H size to 0. Worth a try. I just hope the lens isn't too close to the CRT already.


Cary
 

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Discussion Starter · #5 ·
Hey Cary...yeah well...I think you'll be very impressed. As far as convergence, I think that has been some of my problem...I never dialed in all the way mechanically and had too much drift. It would take 30 minutes to pull together. I just think I can do better mechanically. Isn't there a vertical position mechanical adjustment like there is for horizontal? You kow, like when you center the raster in the tube face. I'm going to search for some of Mike's setup posts, although I don't remember ever seeing this.


You do know that on the deflectionboards there is a coil to adjust width? The one on the green is universal and adjusts red & blue as well. You may be able to bump that a bit and actually back off your electronic size control. That's what I did. But I don't watch any 4:3...DVD and DScaled LD only. Sure would be a lot easier than the lenses ;)
 

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Discussion Starter · #6 ·
Ok, I finally found one of Dr. Newman's posts that specificaly said there is no vertical raster centering on an ECP. SO...should I really be using electonic convergence to pull the ENTIRE red image down 3 inches? and the ENTIRE blue image up 2"? i know that the course adjustment will do just that, but this is the only drift I ever get...takes 30 minutes to pull everything together. Surely there is something....


I thought about tryng to loosent the "mounting bar" and see if I could shift just a bit. Don't know. The final thing to do tonight is the scheimflug, then I'll be off to confergence. Worst case is, since I've got other mechanicals dialed in so well, I could use electronics and see what happens. That way if I have to do a reset and reconverge I would still have all my hard work saved.
 

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Discussion Starter · #7 ·
Also Cary, I did find another of Mike's post and he specifically said that ECPs need one inch. So, 1" it will be. It also has to be measured with a ruer capable of 1/32" so the measurement wil be dead on. Guess I better check mine as well.
 

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Hi guys!!


I'll save you the trouble of doing a search.....No, there is categorically, absolutely, without a doubt, without question, NO mechanical vertical adjustment on ECP's. :( There are, however, a couple of ways to manipulate the PJ to get some vertical raster positioning. Way #1 is to shim the offending deflection coil up or down. Way #2 is to physically reposition the CRT in its mounting flange up or down as necessary. Drawback of #1 is that you are now screwing with the yoke and causing possible distortions. Drawback of #2 is its a pian in the a**.


The 1" distance is the better one 'cause it gives you ample room for shiemflug. I'm not sure what the effect will be if you move it closer, but you're welcome to try.


Last note.... I've really never had a problem with vertical drift - just horizontal - so I can't say its worth trying to mechanically align the rasters.
 

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Discussion Starter · #9 ·
Thanks Doc Newman! We knew you'd come to the rescue! I'd already done the search though...you're too late. Why'd you do that :D


I will try to just use overall convergence and see what happens based on your experience. Your two options both sound like a PITA! But, I will do it if necessary.


1" it is!


Thansk again Mike.
 

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Discussion Starter · #10 ·
Well, I've got drift. I spent about 2 hours on green geometry, never could get the lower 2 corners perfect without a bit (1") of green convergence. Used the overall control to bring the red down and the blue up, then spent 2 hours going over and over convergence until it was perfect. Let a movie run about an our, and I've got the blue drooping on the left side about 1/2". I shut it off and went to bed. Interestingly, I got up this morning, turned it on, and it was exactly at the place it was last night AFTER warmup.


2 things, when I adjust red, averything is exactly as it should be. left arrow moves left, right arrow moves right, up, down... BUT, when I do blue, everything moves at a diagonal. If I push the left arrow, the convergence pulls down and left at the same time. If I use up it goes up/left. Right= right/down. Down=right/down. I can easily use combinations to get the grid to line up, but I am wondering if whatever is causing this could be my vertical drift problem?


#2 I noticed that the mounting plate for the 3 CRTs is slightly different. The blue and read are identical and all "pointed the same direction." Either the green is slightly different (which it appears it is) or it is upside down. I wouldn't think it could matter, as it is just an aluminum bracket, and the vertical spacing appears (to the eye) to be the same. Of course a small amount here could affect a lot at the screen 138" away. But that would make one color (red/blue) closer to green and the other further away since one is too high and the other too low.


Is it possible and would warrant pulling the tube to check the plate? I am also consdering replacing my LVPS the weekend as the squeal from it is driving me nuckin' futs! I think the 12 years old caps are screaming at me. Could LVPS "failure" or wear cause a convergence problem?


I'm running at [email protected] through the PC. The center potion which doesn't suffer drift looks wonderful. The 72Hz ade a big difference for DScaled LD movies...much better than the old 60Hz.


Anyway, thanks for any continued helP!
 

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Jay, your blue convergence yoke is not lined up with the deflection yoke properly. Break the silicone and rotate the convergence/focus yoke to line up properly. Look at how the green and red are done and copy them. That'll probably help your drift problems some.
 

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Discussion Starter · #12 ·
Hey Mike, I'll check just because you said so...but I'm pretty sure it's OK. I was pretty meticulous in making certain it was right on. Remeber, I have one 07MS (blue) and the others are all SD187s. But I will check just to make sure. Would that cause one side to droop/drift?


Mike, what are your opinions in zeroing out all mechanical controls? Cary loaned me an extender board, and taught me how to use a scope (Thanks Cary) so I was going to zero everything out to what the manual said factiry was. I just figure someone somewhere in the past COULD have adjusted something blindly. I've elctonically reset, just want your opinion on the mechanical side.
 

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Isn't the droop caused by a sync phase problem with the convergence? I believe those DIP switches on the convergence board allow you to adjust the sync phase with respect to the convergence zones. Mine droops a bit too but it's outside of the image area (off screen actually) so I don't worry too much. Is yours within the image area Jay?


Also, I remember from looking at schematics (3100/4100), that there are actually seperate Red, Green, and Blue vertical centering circuits on the remote board. They look just like all the other adjustable circuits (contrast, brightness), the output of a DAC drives an opamp and then it goes off-board. Apparently the vertical centering is unused. I had though about hijacking those opamps and installing pots there so that I could adjust the vertical centering seperately, but as Mike pointed out, using convergence to do it works ok. But, we know Jay has a soldering iron and he's not afraid to use it.... :)


Wow Mike. I read Jay's description of the diagonal movement with convergence adjustment and absolutely couldn't even make a wild-*ss guess about it. Twisted convergence yoke would sure do that I would think. You're amazing.
 

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Discussion Starter · #14 ·
Hey Cary,

The droop is about 8 convergence grids wide...so unfortunately it's not off screen. It is basically the entire left 1/3 of the screen.


Me? Use a soldering iron? Never! :D

Quote:
Wow Mike. I read Jay's description of the diagonal movement with convergence adjustment and absolutely couldn't even make a wild-*ss guess about it. Twisted convergence yoke would sure do that I would think
I am going to double check, but if its off, it wouldn't be much (1/8-1/16"?) I wouldn't have thought that could cause anything, but when you're taling around the 1" neck of a tube, I guess maybe that could make a difference. I never thought about this causing the diagonal problems...I was thinking about it from the drift standpoint. I sure thought I had it spot on when I reassmbled it.


Cary, do me a favor (yes, another one :)) when you get home, look at your lenses and try to give me a desciption (or a photo) so I can be assured that mmine are in properly. Or I can try to describe/photograph mine and see if yours are the same. Thanks everyone!
 

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Hey Jay,


Again, I suspect your droopty-do problem on blue is related to the convergence yoke being off kilter. Keep in mind that the wiring harness on bottom of yoke doesn't point straight down at the P defl module, but rather tilts to one side. There is a faint molding seam on the yoke that needs to be centered on top with the defl yoke (it also has this seam). That's your key (see, retubing isn't for amatures...:D). As for the green convergence, go back and zero that out and do it this way: After squaring up as much as possible to screen, equalize any top/bottom keystone error so you have same amount on top as you do on bottom by phisically tilting the PJ or twisting defl yokes. This will also help insure that your H centerline is straight too. The reason for this is that the waveform parabola governing this part of the geometry is usually not quite perfect, causing a "coke bottle" effect. There are actually adjustment pots on the waveform bd (toward the edge connector) that can sometimes help get it dialed in better, but its very difficult, requires a scope, a DMM, and a lot of patience, and you're not gonna get it much better.


Anyway, (now that I've taken a COMPLETE tangent - I'm starting to ramble like Ken) after balancing out the keytone error, use a smidgen of green convergence to turn both areas into pincusion errors (in other words, don't fix the problem with green convergence, just make it an error you can tweak with something stable, like, uh, why PINCUSION! of course...). Now exit out and fix it with top/bottom pincusion and you'll have used MUCH less green convergence and the PJ will be that much more stable. As for starting completely over with all the alignments, I'd advise against it until you've no recourse to resolve seemingly impossible problems. Have fun!...
 

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Discussion Starter · #16 ·
Mike,

I'm gonna print that last post. :)


I'm also going to pull the blue tube. As far as I can tell (standing on a ladder trying to stuff my head between the deflection board and the tube :D) The harness is off at an angle. The seams are lined up on the two yokes. The only thing I can do to check it further is pull it...time well spent if it fixes the problem. I think you are 100% at what the problem is, but from here it looks a-ok. You are in fact the one I went to, to tell me how to cut the clamp off and align the two yokes, so I want to go on record that if you say check it, I'm gonna check it! I'll let you know.


Thanks for the honesty on the adjustments. I have a scope (without a lot of practice), a DMM, and time. But if the result is negligable, then I won't even attempt it. I have been doing exactly as you said...changing into an error that could be fixed...but I have still had to use a bit too much (IMO) green convergence. I'll spend some more time with it after I finish with the blue.


Thanks again Mike.
 

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Discussion Starter · #17 ·
Mike (in my best sheepish grin face :D) Guilty as charged


You are abso friggin' lutely right! That was amazing!


My convergence yokes have two seams...or what looks like two seams. One is actually an indented line. It looks like a seam and is lined up 100% perfect with the obvious seam at the top of the deflection yoke. So I thought all was ok...well, pull the yokes, and 90 degrees (towards the inside of the projector where it was impossible to be seen) you got it, what appears to be the seam you are talking about. Now that I see the two, its obvious that the 1st one wasn't a seam...but it sure fooled me. I don't know if it was a flaw in the mold or what...I'm waiting for hot glue gun to heat up now.


Never ever doubt you Mike! Thanks!
 

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Discussion Starter · #18 ·
Mike, While we're on the conversation of yokes...


What would happen if you glued the yokes together and put them on an SD187 tube? the only reason I ask is that I bought 2 used green tubes (part of a bucket o' parts) and that is exactly how they are. The center clamp has been removed (possibly from teh factory) and the yokes glued together. Perhaps they originally went on 07 tubes and they retubed with some used 187s? Just curious as to the consequences...
 

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Hi amature, 'er, uh, I mean Jay! :D


With the yokes butted together on the 187's it'll still work, but you get the same problem as the opposite situation on the 07MS'. That is, limited convergence and focus manipulation. Quick note on the green convergence situation...when you described your geometry error, you said it was primarily only on one lower corner. The main point I was trying to make is that you will want to equalize that error so that the top and bottom share it, lessening the "range" of green convergence you use on either side. This way, less used = less potential for drift. Does that make more sense??
 

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Discussion Starter · #20 ·
OK, rub salt...:D


Yeah I understand the convergence aspect. I spent a week at Runco a few years ago and I do the final install on our projectors. Made perfect sense. That was one thing they preached...balance the errors...don't try to fix everything at once...a little here...a litte there....


I have never done "service." Until this pj, I had never seen an ehome! What I am learning from you is the service side. Replacing this and that...never doen that before. This was the 1st CRT I've ever changed. I had a tech (until last August) that did it for me. Gee that was nice!


I figured as much on the yokes. Just curiosity. Thanks again old man :D


You asked for that one!
 
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