AVS Forum banner
1 - 19 of 19 Posts

·
Registered
Joined
·
889 Posts
Discussion Starter · #1 ·
Due the inability to shift my raster (it is somewhat off centre) I've been running it slighty off the tube so I can keep my distance to screen where I need it.


The actual image, however, always remains on the tube (sometimes very close to edge).


Different posts seems to suggest different things (i.e., it's ok, it's not ok).


I can't remember where I read it but I thought it was the actual image that would cause damage to the tube. But maybe I am slow-cooking this thing and don't even know it.
 

·
Registered
Joined
·
4,018 Posts
Depends on the projector. On NEC's you CAN pop the tube doing that and most certainly overstrain the electronics. On some sony's it does not seem to hurt at all.


Marc
 

·
Registered
Joined
·
4,175 Posts
Doesn't seem to hurt my G70. I've been running the raster off the tube face for 3 years.
 

·
Registered
Joined
·
889 Posts
Discussion Starter · #5 ·
I should have added it's a ECP 3100.

I think it's been running off the tube for about 2 months or so. No ill effects...yet.


When I run my HTCP I can pull them back in and off the tubes and decrease porch sizes to get more raster real estate.


However, it's the terrible porch sizes of the Xbox 360 720p/480p source that make it next to impossible to avoid running off the tubes to get a decent image size.


I assume it's normal for the raster size to move proportional to the image size on an ECP...at least it does on mine.
 

·
Registered
Joined
·
7,138 Posts
If you keep the actual image content within the tube face, you won't do any damage to the tube itself, but could stress the deflection electronics. I really depends on the projector model.


For example (out of the PJ's I've owned and am familiar with): NEC XG's and PG's should keep their rasters within the tube face - you really need to keep the raster as narrow as possible as these PJ's don't like wide horiz deflection.


Most Barco's however don't mind a really wide horiz deflection. You can go as wide as you like. I ran my BG800 for many years with a raster that went quite a bit off the tube face since the left side of the raster was somewhat unstable so I shifted the image to the right side of the raster and shifted the whole thing to the left to compensate.


Kal
 

·
Registered
Joined
·
221 Posts
XG 1100 here and I have had the widest part of the trapezoidal image area at 3mm from the edge for about three years, but thats just me.... of course if that turns out to be too close for yours, just remember.

I DON'T recommend NOTHIN about NOTHIN to NO-ONE! ;-)
 

·
Registered
Joined
·
3,480 Posts
I'm using less horizontal deflection then what is normal for a stock 10PG with the image right up to the edge of the tube. I did this by using a front porch of 8 and a back porch of 24. I also pulled the deflection yokes back a little. Less stress on the H-deflection circuit and SMPS. The tube and yoke may even run cooler without the coil of the deflection yoke up against the tube. A little air circulation should help keep things cooler.


Deron.
 

·
Registered
Joined
·
5,876 Posts

Quote:
Originally Posted by Phil Smith /forum/post/0


Yep. You wouldn't think it would hurt an XG either.

Ballzy!


Not me. Even at about 1/16" I am scared to death. But also other things suffer such as corner focus and convergence.
 

·
Registered
Joined
·
4,175 Posts
Well I don't run the picture off the tube face, just the raster.
I have actually reduced the size of my picture over the years because of corner distortion that requires too much adjustment to fix, if it can be fixed at all.


Corner focus is not an issue to me. I think it's very over rated. Other than Window's desktop, I never notice whether the corners are in focus or not.
 

·
Registered
Joined
·
5,876 Posts

Quote:
Originally Posted by Phil Smith /forum/post/0


Corner focus is not an issue to me. I think it's very over rated. Other than Window's desktop, I never notice whether the corners are in focus or not.

Good point. I don't even bother with electronic focus for the corners. Not even top and bottom (I am running 16x9). I only go thru center, left and right. I guess I am not anal.
 

·
Registered
Joined
·
889 Posts
Discussion Starter · #13 ·
I was hoping for more "don't worry about it" comments but it's good to know. Thanks guys, always helpful people here.


Looks like I have three options.


1. Move the machine back (will be cramped/next to impossible).

2. Use green convergence to move raster over and then do same to red/blue (major drift issues would likely follow...)

3. Try to figure out why the DC offsets don't work (have swapped out power deflectors, confirmed all three are same board model/number).


Just in case I've been unclear (I had the HTPC/Xbox 360 problems switched around), this is what I am seeing. As far as how "off" the rasters are the blue is the worst, green best, red in the middle.


Needless to say, the internal convergence grid flys off the tube to the right so I don't use it and run one off the PC.
 

·
Registered
Joined
·
4,175 Posts

Quote:
Originally Posted by CaspianM /forum/post/0


Good point. I don't even bother with electronic focus for the corners. Not even top and bottom (I am running 16x9). I only go thru center, left and right. I guess I am not anal.

I'm with you! I'm just not that anal either. Perimeter focus just does not make that much difference under normal viewing conditions. I use to think minutiae was important, but these days I find myself questioning if what I'm doing REALLY makes a difference. More and more often the answer is "no".


The only thing I still get anal about is convergence. You can't achieve a sharp picture without nearly perfect convergence.
 

·
Registered
Joined
·
7,626 Posts
Run the raster off the tube? I've never even been able to do that with my Marquee when I want to. Well, at least not with keystone close to center at 50.


If anyone knows what resistors to change so I can get my raster to be wider, please let me know.


I'm already at 100 width with perfect corner focus, so I feel I can achieve more phosphor useage without sacrificing corner picture quality!
 

·
Registered
Joined
·
94 Posts

Quote:
Originally Posted by CZ Eddie /forum/post/0


Run the raster off the tube? I've never even been able to do that with my Marquee when I want to. Well, at least not with keystone close to center at 50.


If anyone knows what resistors to change so I can get my raster to be wider, please let me know.


I'm already at 100 width with perfect corner focus, so I feel I can achieve more phosphor useage without sacrificing corner picture quality!

What about the width coils on the hdm? I just kept crankin mine till I got what I wanted.

The widest tip of my image is almost at the end of phosphor.
 

·
Registered
Joined
·
7,626 Posts
Yup, my HDM green coil is already maxed, with the red/blue adjusted to match.


Not just this Marquee though, I've never been able to get any Marquee to float the rasters off the side when keystone is @50 (centered).

Thanks for the suggestion though!
 

·
Registered
Joined
·
4,355 Posts
Not sure but on my Refrence 8 i cant even see where my raster is! i think the whole thing is off the ubes,tops and sides. when i lower contrast and raise brightness it looks even over the entire face of the tube. Its freaking me out! no raster?


Athansios
 
1 - 19 of 19 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top