CurtPalme.com Home Theater Forum

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

There are 3 XG manuals. 1 for the 750,1100,1350....1 for the 751,1101,1351...... and one for the 852,1352. I looked through the 751 series manual on the video out board adj procedure and again its states after the intial procedure to measure color temperature. If you also look in the manual, most of the pot are indicated as bias, blk bias, sub contrast and other various form of color manipulating. I also have a PG and XG test chassis here and I have personally F-ed with these various controls with an on screen pattern and what I saw was various color tinting on upper and lower levels which is why I stated these could probably be adjusted with a colorimeter, Any pot I adjusted did not make drastic changes in brightness or color strength. If I had the time and a colorimeter I would try the test myself, but I felt it could be an option for anyone who ended up with a F-ed NEC to get a better pic at little cost. Being an electronic tech I would never disagree with a service manual and scope setting procedure but I also know there are sometimes other alternatives.

To each his own I guess but this is how I got the Macgyver nickname. I have never been afraid to experiment on something and learn from the alternatives.

**kal** · Posted: Mon Sep 01, 2008 3:17 am Post subject:

While you guys are allowed to mess around and try different things, I really don't see how you could possibly 'compensate' for incorrect internal settings by forcing external settings to something different.

The XG is like any closed system. You can't compensate for all incorrect internal settings by manipulating external settings. A good example of how this wouldn't work is a car that's stuck in first gear because the transmission is broken (this is the internal setting that is wrong). No matter how much harder you press on the gas pedal (an external setting), you're never going to get that car to go 150 mph.

Kal

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

So I guess what your saying Kal is that anyone wanting to use your grayscale for dummies calibration should not go into the service menu for corrections unless they have a scope and service menu. The pots on the PG and XG are marked similarly to the same adjustments available in these service menus. The only difference is the adjustments are electronically controlled through software in these systems.

Also as far as internal vs external settings, I never indicated to skip one to force the other. Like any other display I would neutral out the regular menu items before adjusting the internal ones, Just like it states in the NEC manuals. Most internal controls(pots or service menus) are to reset the range of adjustments in case the regular adjustments (W/B) are nearing the end of their range, whether its hi or low, or to compensate for tube condition. No scope is going to allow for tube condition, period.

Also in the PG and XG service manuals they are very specific about using a colorimeter to check balance after making scope adjustments and to adjust as needed. Scope is used for initial adjustment then colorimeter for final. I'm only suggesting a possibility this can be performed just with the colorimeter. Again all these adjustments are for color balance and gray scale. Isn't that what the colorimeter is for?

Oh, and try adjusting the shift linkage. It may not be internal after all. Smile

dropzone7 · Joined: 12 Jun 2007 Posts: 1069 Location: Charlotte, NC

This conversation is waaayyy too serious for midnight! Shocked

**kal** · Posted: Mon Sep 01, 2008 4:53 am Post subject:

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

Yea Drop, your right. Its probably because it so late.

Hey look Kal, I'm not trying so say that you or Mark are wrong, I'm just trying to encourage those who have no scope knowledge to not pass up on a NEC because it may have been tampered with. With some time and effort you may still be able to get a good picture without electronic knowledge. And that was my only point.

Mark_A_W · Posted: Mon Sep 01, 2008 6:21 am Post subject:

Yeah, alright, I reckon you could get by doing what you suggested at the top of this page.

You probably can set most of the pots by eye, but only if you understand their affects and what would happen on the screen, and it sounds like you'd get by.

For most of us it's actually easier to just follow the manual with a scope!

stefuel · Posted: Mon Sep 01, 2008 11:45 am Post subject:

I have not worked on a NEC for a very long time. I seem to remember that all those pots have to do with setting a "base line" for the "AKB" circuit to do it's thing. I have gone through all those adjustments once on a 9PG+ and it took 2-3 hours of back and forth to get everything within limits.

**AnalogRocks** · Posted: Mon Sep 01, 2008 2:39 pm Post subject:

larryk · Joined: 23 Aug 2007 Posts: 106 Location: Edmonton Alberta

3 pages into this thread the poor guy who just wanted to get some advice about buying his first crt is probably wondering what the hell he's gotten himself into Shocked

In reading through the various posts I have learned a bit about crt setup in terms of what not to touch but getting back to the original question here, is 550.00 a reasonable price to pay for an XG?

Lets make a list of things to look for so when he goes to check out the PJ he has some idea what to do without making it too complicated.

1. What to bring with you to test with
2. What to look for
3. What to go into with the remote to check the unit out.

We need to keep it simple enough for a newbe and not too involved that it takes hours to complete and in point form so it's easy to follow. Details of proceedures can be referred to Curt's setup guide etc.

1. flashlight, philips screwdriver, Test pattern DVD,
2. wear patterns on tubes, White field,
3. Ramp bightness, contrast, focus?

That's a start

dropzone7 · Joined: 12 Jun 2007 Posts: 1069 Location: Charlotte, NC

larryk, good point regarding keeping it simple. I know that would have been good advice for myself when I was first looking. Of course, test patterns are not going to do much good unless the projector is still in service projecting onto a screen. I didn't notice in the first few posts whether or not the projector has a remote either. If it does then great, if not then that's going to be an added expense of $50-$100 and will be needed to easily check things out with the projector. I would pull the lenses and take a good look at the tubes. If they look clean with no visible wear then $550 is a fair price. I would pull the lenses off in order to load the projector in my vehichle anyway so it's a good excuse to see the tubes for what they are.

Satanier · Joined: 25 Aug 2008 Posts: 185

This is becoming quite an interesting thread! I'm still here lurking, and taking in all this information.

Spanky Ham · Joined: 22 Mar 2006 Posts: 5643 Location: Comedy Central

I think the worst case scenario is that the pots are tweaked and the tubes are toast. If the tubes are in great shape and the pots are messed up, then you could still hire Doug Baisey to come out and fix them. Along with taking care of the pots, he would be able to do a perfect align, converge, and calibration.