CurtPalme.com Home Theater Forum

[TheyDroppedMe]

Well, I've been trying to get the setup on my 9 PG Xtra dialed in, but I'm coming across some things that seems very strange to me. First of all, I can't seem to get my focus dialed in. I've been trying Guy Kuo's phosphor grain focus technique, but It seems that it never really gets perfectly focused. Maybe the corner focus adjustment needs to be set one way - all the way CW, CCW, or right in the middle - before I try to get the center focus set?

Also, my electronic focus seems strange in that all of my tubes have to be set to -60 to -80 to be the sharpest. Is that normal? No matter what I do either optically or electronically, I can't seem to get razor sharp lines on the projected image (1080i), and seeing scan lines is near impossible (contrast at 52). Am I missing something, or do I just need to spend more time on optical focus? When I look at the phosphor through the lens, scan lines are immediately visible. Strangely, even with the blue defocus, I can get my blue tube RAZOR sharp on screen. I keep it defocused for white balance, but I wish I could get the red and green that sharp. I seem to have a lot of flaring on setup.

If someone could explain how to set astigmatism, I feel like it might help improve my picture. I'm trying to use Guy Kuo's setup for astig, but I can't see any difference when I change any of the controls, so I just set them all to the middle. What is each control supposed to do? Because the projector defocuses the tubes when I go to the astig controls, I can't even read what each control is and what they are supposed to do.

Keeping going, I have it fed by a HDfury2 and GammaX, and in order to see 2.5 IRE I have to set the brightness to 80, and the GammaX (yes, both have power adapters). Even then, everything seems washed out if something bright is on screen, and the black levels look wayyyy too high compared to what I've seen in other CRT's. When it's a high APL, the blacks are virtually grey and washed out - is that just because I have an AC projector?


Thanks guys, I would appreciate any help you can give, and if anyone in the North Metro Atlanta area wants to waste an evening helping me set this us, well there might be some free beer and parts to a 9 PG Xtra, or a complete setup gets you a set of HD-145's... Wishful thinking I guess haha.

Greg

[TheyDroppedMe]

just to add, when I have a full black 0 IRE screen up (COMPLETELY black screen, no text or anything), I can still make faint shadow puppets. I feel like I shouldn't be able to do that...

[benareeno]

You need to set astigmatism (check under advanced procedures link above)

You need to zero out your menu focus adjustments, and adjust focus with the pot on the deflection board...then you can use menu focus for a little fine-tuning.

[Artinaz]

Brightness setting of 80 seems way high. Mine is a light controlled room with velvet on the front and side walls- my brightness setting is at 20. However, this gets the middle IREs too dark- so I have the curve on my nvidia video card set so that it gives the middle IREs a boost. You should be able to acccomplish the same with your gammaX.

Coupel of questions-

1. Do you set your brightness levels etc with the gammax in the chain or without ? Essentially, do you do the brightness setting for 0IRE andthen after its setup do you throw the gammax in?

2. For your focus, first thing to check is if the projector square to the wall ? What is the recommended distance from the NEC projector and how far do you have it ?

3. Did you us eteh focus trim pots to adjust teh mid zone focus ?

For seeing a difference with the astig, your focus has to be very accurate. If there is anything wrong with the focus boards for example, I have seen that the astig magnets dont make a perceptible difference.

[TheyDroppedMe]

ok so for electronic focus I should zero out everything in the menu, and do the focus with the pots. How should I handle the blue tube? defocus switch on or off? Before I get into the electronic focus however, I want to ensure that my optical focus is spot on. How should I set the mechanical focus (i.e. when focusing the center, where should the corner focus be set at?).

As for the brightness issue, I did the calibration with the gammaX in the chain. Would the G2 voltage be causing some of my brightness/black level issues, and if so how would I check/set it?

The projector is perfectly square with the screen, and is set at the recommended distance per the NEC manual.

Thanks again for the help guys, I just want to get this thing looking as good as I possibly can - I would give up on a little bit of focus if I could figure out the black level issue, I don't want to see any light on full black...

[Curt Palme]

First off, the NEC distance is WRONG. THey use too little phosphor. Move the set 7% closer to the screen (unless you have tube wear already), and start over.

Sorry, but this will add about 2000 usable hours to your tubes if they are mint now.

[Curt Palme]

First off, the NEC distance is WRONG. THey use too little phosphor. Move the set 7% closer to the screen (unless you have tube wear already), and start over.

Sorry, but this will add about 2000 usable hours to your tubes if they are mint now.

[TheyDroppedMe]

curt - Yeah I know the distance is wrong, but there is some pretty decent wear on (only) the green tube, so I set it up about 5 inches closer than the NEC manual (on a 92" diagonal 16:9 screen) to stay within the lightest wear pattern (there is still about 4" of less-worn phosphor visible on the left/right sides of the screen). I figure if I can get about 3000 hours out of the tubes I'll be ready for an upgrade when I decide to build a house.

[Curt Palme]

OK, then you're good.

You're dealing with a few issues here regarding focus, and you need to deal with them in order.

1) Elecrtonic focus/ astig
2) Optical focus.

To deal with the electronic focus and tube astig, I put contrast to 100%, and put on sunglasses and look right into the lenses. Once the astig and focus is bang on (round dots that defocus evenly and the defocused dots stay round, then you've nailed focus and astig perfectly. the rest is optical, and at that point don't touch the electronic and astig settings.

Once optical is done, then you can go back and slightly tweak the electronics, but chances are you won't need to if you did a careful electronic adjustment.

[Curt Palme]

OK, then you're good.

You're dealing with a few issues here regarding focus, and you need to deal with them in order.

1) Elecrtonic focus/ astig
2) Optical focus.

To deal with the electronic focus and tube astig, I put contrast to 100%, and put on sunglasses and look right into the lenses. Once the astig and focus is bang on (round dots that defocus evenly and the defocused dots stay round, then you've nailed focus and astig perfectly. the rest is optical, and at that point don't touch the electronic and astig settings.

Once optical is done, then you can go back and slightly tweak the electronics, but chances are you won't need to if you did a careful electronic adjustment.

[TheyDroppedMe]

I'm trying to get the electronic focus spot on, but I can't seem to focus it right - without perfect optical focus I can't use the projected image, and when I'm looking into the lenses, well It's too small to get perfect. What to do? Should I retry the phosphor grain technique?

Any ideas on the brightness issue? I checked, and I have the gammaX all the way up, brightness at 80, and it still seems like I'm missing some shadow detail. And the high brightness seems to KILL the ANSI CR during high APL scenes. What is wrong with this $^()I!@R@!* projector?!?

Thanks,
Greg

[Elaine Benes]

You have two issues with your projector, neither is a good one to have....

Elevated black level. First off that is likely a result of someone at a point prior to your ownership fiddling with the white potentiometers on the edge of the video card which set the reference mechanical white balance. It is not uncommon for this to have happened to an NEC, they seem to be a magnet for inquisitive, yet un-skilled hands.

IF your reference mechanical white balance has been changed, you're likely never going to get a good setup from the projector, period. It takes a real NEC factory trained technician and an expensive service call to get the projector back to a factory set state. Many people here will tell you that you can do it yourself. I've seen NEC's that have been re-done by all levels of hobbyist, and imho, they're all worse than a projector which has its factory set reference mechanical white balance in tact. If your reference mechanical white balance has NOT been compromised and you are getting elevated black levels at a no signal condition, then the pedestal level of your projector may have been adjusted incorrectly at some point in the past. If this is the case, basically you won't be able to get good fade to black AND shadow detail. Research at AVSForum archives for Guy Kuo's trials and tribulations with the incorrectly set pedestal level of his XG135. It was incorrectly set and he suffered with it set that way for a long time before discovering and correcting this...

As for focus....

The impossibility of you getting your focus correct indicates to me STRONGLY that your set has likely been totally screwed over by a previous owner. NEC's have some of the absolute best, and most powerful focus tools built into them, BUT they are all predicated on the MECHANICAL control of the electron beam being set correctly. There are two sets of magnets found on each individual tube neck, at the back, closest to the neckboard. One set controls the core of the electron beam, its directionality and shape, the 2 pole set, the other set controls the flare of the electron beam, again its directionality and shape, the 4 pole set. To check your mechanical astig, do this.

First have a signal going to your projector.

Next, choose from the internal test pattern menu "Dot Fine".

Next turn your contrast all the way up.

Next choose a color, then turn off the other two colors.

Next choose "FOCUS" and then the "Center Focus" control. Make sure you have the corresponding color chosen as the one you will control.

Now the part that will tell you if your mechanical astig has been screwed with....With the contrast all the way up, the internal dot pattern chosen, only one color at a time displayed, and you controlling the center focus for that one pattern, ramp your focus from all the way under focussed(-100 on the scale), up to all the way overfocusse(+100 on the scale). Watch the dots while you do this. You should see several things.

First, at all the way under-focused you should see a dark dot inside a lighter colored haze. The darker dot AND the haze should be perfectly round, ESPECIALLY IN THE CENTER ZONE OF THE SCREEN. If you can't EASILY make out a dark dot in a cloud of color, your beam's core shape is compromised. Note that both the dark dot and outer shape are not defined in a razor sharp manner, BUT are easily distinguished....

As you ramp the focus from completely under to completely over focused, the dots should collapse in onto themselves to a very brilliantly sharp point(which ideally occurs at a focus setting of "0" on your scale), AND THEY SHOULD NOT APPEAR TO SHIFT AT ALL.

IF the grid of dots shifts while you ramp the focus, the directionality of the beam is not correct, it is being directed to hit the phosphor at an angle, instead of squarely.

Now, at a completely over-focused position, you should see big, fat, perfectly round dots with no discernable spot on the center, the OUTER edge should be fairly well defined and dark, with a cloudy center. This indicates the flare, or outer halo of electrons is set perfectly by the mechanical controls which do this(4 pole magnet set). If you observe oblong dots or slash shaped dots, your mechanical astig is not set properly. Also, if you see fairly cicular shapes which have a VERY BRIGHT area only at one point in the outer edge, your mechanical astig is not done correctly.

Let us know your results of this test.

My bet is your mechanical astig will not prove to be set correctly. If that turns out to be the case, you have a LOT of research and experimentation to do...

[TheyDroppedMe]

Hey guys, thanks again for the help - I've had a pretty rough patch in life recently and I'm just getting back around to working on my setup (strangely, it's somewhat therapeutic).

I've decided to start from scratch and redo my entire setup, as I'm using wayyy too much point right now. I think it is causing my problem where reds will bleed horizontally across the image, but I want to get everything squared up from the ground up first. I am going to follow the great "Rasters on NEC XG-75" thread as a starting point.

I've got the focus dialed in with the pots now, geometry/convergence, and the excessive need for brightness (contrast at 58, brightness at 80 ). If it comes to it, I do have access to an oscilloscope and an electrical engineer if the white balance controls are indeed messed up. Is there a guide for this procedure anywhere? I know it is advanced, but I'm not afraid of hard work. But I am not even going to think about the white balance pots until I have tried EVERYTHING else, so I'm more just trying to figure out if it's even feasible to consider.

Back to my original points, right now the things that are bothering me most right now are the red banding problem (I think this might be too much point, anything else could cause it?), and my convergence.

I have just a couple questions before I get started on my setup:
1) How do I copy the working Input and settings I have to another slot, just so i know I have a working backup.
2) When doing the setup, should I be working with the controls in the Alignment or Convergence menu?
3) What's the best way to thank you guys once I get everything setup?

-Greg

[Curt Palme]

You will NOT be able to get the white balance right if you start tweaking controls. If you do, I'm buying a ticket and will come and see you, as this is something that even the most die hard NEC tech (Doug Baisey) was never able to get. The guide in the service manual is so screwy, you may as well rip them out of the manual, and replace them with:

'adjust trimpots at random, and hope to heck you get closer than when you started'

Copying the input- use the 'data copy' in the signal entry menu to copy the data to another location.

Start with the alignment (green tube) first, then move to convergence.

To thank us? SHoot a digital projector.

Have you seen this? It's for an XG, but the procedure is very close for an Xtra:

http://www.curtpalme.com/CRTSetupGuide.shtm

[Curt Palme]

You will NOT be able to get the white balance right if you start tweaking controls. If you do, I'm buying a ticket and will come and see you, as this is something that even the most die hard NEC tech (Doug Baisey) was never able to get. The guide in the service manual is so screwy, you may as well rip them out of the manual, and replace them with:

'adjust trimpots at random, and hope to heck you get closer than when you started'

Copying the input- use the 'data copy' in the signal entry menu to copy the data to another location.

Start with the alignment (green tube) first, then move to convergence.

To thank us? SHoot a digital projector.

Have you seen this? It's for an XG, but the procedure is very close for an Xtra:

http://www.curtpalme.com/CRTSetupGuide.shtm

[TheyDroppedMe]

thanks curt, Well I guess I will leave the white balance alone no matter what. As for the digital thing... I am going shooting this week, and I do have a dirt old infocus... I'll have to think about that one as it just needs a new bulb (I know I know, real surprising right). And I've read your guide three times now - it will be integral for my setup along with the thread I mentioned.

Now I just need to get my motivation back after watching the Tech game...

-Greg

[benareeno]

what happens to you picture when you switch the test/norm switch on the video board?

[benareeno]

or when you hit the kelvin button?

[TheyDroppedMe]

well, I havent checked the test switch, and I can't seem to find it in my cursory look. Exactly where is it located again?


When I hit the kelvin button it brings me to the RGB adjustments - From what I remember, Green is around 52/48, red was like 60/48, and blue was like 57/55. Those are just the rough grayscale I did by eye so that I could start watching things - I have an eyeone display 2 (calibration seems wayyyy off), a spyder 3, and a surprisingly accurate spyder 2.

So here's What I'm thinking, I can't see any bubbles so I am going to have to pull the projector off the ceiling and bleed those. Since I'm going to be deep in the heart of the beast (I Have extra boards for everything except the system board from a working spare w/toast tubes), I want to do a complete setup of this machine, save for the astig magnets at this point as they are still factor sealed and the astig seems pretty decent.

If you were doing a COMPLETE setup literally from ground up, what would you do? Maybe there are a few boards to replace (any wear over time, or show visible wear? just throwing all my ideas out there). I'm approaching this in the same way I went about rebuilding my 1965 mustang back in high school - The absolute most inner core fundamentals first.

If you guys wouldn't mind helping me build out a list of what I'm going to do after I take it down, and then Once I get it hung again, I'd really appreciate it, and I'd even turn it into a HOW-TO guide for future reference. Here's what I've got, with the * denoting something I probably need input on:

Projector on the Work Bench
- bleed all tubes
-* reseat all boards and connections
-* visually inspect all components (which/if any would be visually worn?)
- reassemble

Mounting the projector again
- Make sure the projector is PERFECTLY aligned with the screen (i.e. correct distance, prependicular, and square)
- Copy current working settings to another input


Adjusting the projector
- NULL ALL SETTINGS
-* center rasters
- mechanical alignment
-* Make sure all appropriate DIPs are set properly (test, akb, defocus, and what else?)
- Phosphor Grain Optical focus
- Electrical Focus with pots
-** Astig setup
<close projector and do everything else via software>
-* Geometry
-* Convergence
- Point Convergence
- Greyscale calibration
-* Adjust settings that I have no idea what they do right now, but should be adjusted

If you guys are willing to help me through all of this, I'll send the top 5 contributers an actual present in the mail. Seriously.
What else do I need to add to my list, is anything in the wrong order, and what (if any) tools would I need to make sure I have before starting all of this?

It's going to be a long journey, but I am determined to have the best setup NEC 9PG Xtra ever haha. I am very technical (engineering background) and persistent, so hopefully this will end up being a great experience for me, and leave me with a truly comprehensive knowledge of setting up this projector.

Thanks in advance,
Greg

[rtart]

So theydroppedme, how about an update?

Just as an FYI, this PJ was purcahsed from Curt in 1998 and was my unit until bought by the OP. I can assure you there was never any adjustment by me to any pots on any boards.

The good news is that there was a complete set of extra boards from another Xtra with bad tubes that went with the PJ.

[CasetheCorvetteman]

The red drifting is NOT caused by too much point convergence if it is what i think it is.

If it is indeed what i think it is, youre seeing the red image smeared to one side horizontally, and that i believe is due to the G2 settings being incorrect, i just made some changes to my NEC the other night and cured that red smear issue, i wasnt seeing it on anything through RGB, but with video game consoles it was doing it whether they were PAL or NTSC.

The G2s on my NEC had been adjusted by the previous owner and got bumped during ceiling installation and id never checked their levels since it went up, since doing that, the black level doesnt creep right up to the point it takes over the bottom 25% of the dark scale, and the red smear is gone.

Dont know how youd adjust that on an XTRA, but my recent experiences suggest its worth a look