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Discussion Starter #1
In their guide it says to setup the raster to with 1/2 inch all around, is this the amount to use to maximize phosphur usage or is this the NEC standard amount which results in the projector being too far from the screen?


THanks,


Ben
 

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I would go with the image to 1/2 inch. Or even up to 1/3 inch

Roland
 

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The thing with NEC's is, in order to NOT stress the convergence and focus circuits, you pretty much have to live with not using as much of the tube as most manufacturers. Maximize your size with the largest source you have, then do the raster centering. Make sure you center your test pattern inside the raster too. One can do things to use more of the tubeface on an NEC but if one does this, they run the risk of physically damaging circuits in the projector.

There seem to be two distinct schools of thought about which approach is best with NEC's represented on the forum. I am in the school which says DO NOT frig with the factory spec's, and accept a smaller raster when compared to another manufacturer. As such, yes, the half inch or so all around is what you end up with. You can be sure of a good setup position by maximizing phosphor use FIRST, then finding the physical position where this size fills your screen. A little more tedious, but perhaps it puts your projector in a slightly better position to use more of its potential.
 

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I've got a 6pg that has been setup with approx 3mm of space between the raster and the tube edge....It's working fine at the moment,but I'd feel safer if it was smaller.


Read that the H raster control is on the deflection board,and can be ajusted from there.

Looked for it ,can'y seem to find it.....Which side is it on ?...near the blue defocus switch or the other side?


Iv'e zeroed all the settings as recommended to start afresh


While I'm questioning about the 6PG...the top and the bottom of the raster are presently concave on all three tubes....I've tried using Keystone and it has NO effect.


Iv'e only tried movements with the Green tube,Iv'e left the others alone.


Iv'e got Guy Kudo'S setup procedure and Tinmans+Feathers setup guide+ NEC setup manual .

Another problem is ...following Tin/Feath setup guide.

Test patten centering...can't for the life of me get the test patten and the image centered.


Iv'e wiped all previous settings....problem is with the NEC setup manual stating controls for the full function remote..RC-6011

I did not get a remote with mine so I got a replacement one from the US..

RC-6051.

Not much difference except when you go to ajust the PHASE,,,this is where I'm confused.

Tin/Feath discription in the setup guide on how to get the internl test patten working with the signal is to use the- quote{Test Patten Cursor}

Pressed PHASE..used the cursor ...ZILCH!


It's probably something really basic that is right in front of me ...but I'm still stumped.


PLEASE HELP THE CONFUSED!
 

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Could sombody post a link to this guide? I did a search but nothing came up. THanks!


-Tyler
 

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What's more important is how big you run your active image. I have experimented with my NEC and an old set of tubes with the raster run past the edge of the tube and the active image to 1/2" of the edge. With the black level set properly, the raster should be completely black or off. With no energy at the tubes edge, you should do no damage. I'm no expert but that was my findings.


Chip
 

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Chip: My opposition to exceeding the NEC specs has more to do with damage to the convergence and deflection controls and the difficulty of focus in the corners than with any fear of tube damage from having the raster scanning onto the sides of the tube.
 

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So what exactly gets damaged, and what components are being driven too hard?
 

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Quote:
Not much difference except when you go to ajust the PHASE,,,this is where I'm confused.

Tin/Feath discription in the setup guide on how to get the internl test patten working with the signal is to use the- quote{Test Patten Cursor}

Pressed PHASE..used the cursor ...ZILCH!


It's probably something really basic that is right in front of me ...but I'm still stumped.


PLEASE HELP THE CONFUSED!
I am confused about this point of the guide as well - I don't have a remote and I am using the Pronto .ccf for the 9PG from RemoteCentral - there is no button labeled 'PHASE' on it - should there be?


thanks-


Chris


- never mind, answered my own question - I found another .ccf which has a 'phase' button so I am going to try that one.
 

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or maybe not... I just looked more carefully at the install manual for my CRT (it's a PG-6000) and there is no 'PHASE' button mentioned in its description of the service remote.


So I guess my real question is, with a PG-6000, how can you adjust the position of the test patterns within your raster? Or can you not do it on this model?


thanks!
 

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Quote:
Originally posted by gn2
The thing with NEC's is, in order to NOT stress the convergence and focus circuits, you pretty much have to live with not using as much of the tube as most manufacturers....
Doug Baisey (resident NEC expert) had a good post about a week ago saying pretty much the same thing. Seems that it's fairly easy to blow the H-drive output transistor(s) if you drive your image size too wide to maximize phosphor usage.


I only have 1/8" free on the sides at the narrowest point on my BG800 so when I had an XG75 to play with I tried to do the same. It was a lot of work to get that wide without touching the pots in the XG (had to play around with powerstrip's front/back porch settings quite a bit) but it was do-able.


If a had another NEC around I think I'd err on the side of safe now having read about all the blown H-output drives around here.


Kal
 

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cpurvis : On a first generation PG the Phase will be in the service area of the convergence(I think). Where it is on the first iteration of the PG tells you how old the version you have is. I've got a manual page somewhere that expains it but I'll never find it now(not since the move). BUT, sign on with the service passcode of 2580 after you've setup a regular passcode and backed out to user mode. You should find Phase added to the bottom of one of your menu's, Alighnment or Convergence, I can't remember which.
 

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Okay - thanks!


Chris
 

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The situation also becomes worse as people try higher and higher scan frequencies. Higher horizontal scan frequencies make the raster shrinks horizontally and increase the temptation to overdrive the horizontal deflection circuit in an attempt to stretch the picture back up to size.
 

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I think in the PGs there is only one H-Deflection power transistor that gets all the load.

In the GP-3000 there were 6 transistors sharing the load and so the deflection is very stable there.

I think in the Xgs they learned from the PG failures and distributed the load on more transistors, but I don't know for sure...

Roland
 

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Hi,


some ideas on maximizing raster width while still staying in spec with the NEC's:


1. use a PC and reduce non-active pixels (front back porches, sync width)

2. use 21:9(2.35:1) and 16:9 instead of 4:3 resolutions where possible/applicable

3. Avoid preset resolutions that are known to have extremely large porches (most 1280 x 720 presets come to mind)

4. If possible and applicable prefer 48Hz to 60 to 72 or higher and 50 Hz to 75 or higher


These are pointers and each of them could be discussed at lenght, but these are things that can be done properly and have been done already with a lot of units I know to be in use for years without trouble.


I have used three NEC's of the PG and XG series with maximized rasters for 4 years without a single failure and more than 3500 hours run time.

Raster usage of the active picture area has varied from 95 to 99% of available phosphor width most of the time and no detrimental effects have been seen at any point in time.


DISCLAIMER: raster maximizing is something everyone undertakes under his own risk and I'd recommend thorough reading in this and the HTPC and processor forum and using the search function before going at it.


Oliver
 

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Regarding the PHASE control-again{sorry but this is really getting up my nose}

Iv'e gone to the phase control to try centering the test patten within the raster after centering the picture signal.

Nothing is happening,Iv'e got the phase cursors up on the screen,but pressing the controls doesn't move anything {test patten wise}

Is there something that Iv'e missed?

After reading the outdated installation manual that I downloaded I am rather confused.

I noticed that the input signal has to be" locked "via instructions with the manual.

Apart from pressing enter,is that how one locks the signal in?

I must be missing the point somewhere along the line,just where,I'm stumped.

Rather frustrated
 
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