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Discussion Starter · #1 ·
Hi all,


I've been doing an intitial mechanical setup on my NEC 9PG+ and i have a question. I have this same question buried in another thread but I thought it might be best to post it here.


During the mech setup, after the raster, vid image and test signal are centered on the CRT, one of the steps is to turn the green focus adjust pot and see how that affects the focus and most importantly see if the green crosshair test pattern MOVES. That will tell you if you need to make an astig adjustment.


The question is HOW MUCH MOVEMENT or what KIND of movement am I looking for???


I adjusted the pot and going in one direction the crosshair would blurr (or flair) to one side and then when i moved the pot in the other direction, that blurr went away, the pattern focused and then it blurred (flaired) to the other side of the crosshair lines. The main lines of the crosshair did not move but it did flair to one side or the other depending on which direction I was moving the focus pot.


Since I've never seen this done before I'm not sure what to expect here.


Thanks

Jim
 

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Quote:
Originally posted by Feathers
Hi all,


I've been doing an intitial mechanical setup on my NEC 9PG+ and i have a question. I have this same question buried in another thread but I thought it might be best to post it here.


"During the mech setup, after the raster, vid image and test signal are centered on the CRT, one of the steps is to turn the green focus adjust pot and see how that affects the focus and most importantly see if the green crosshair test pattern MOVES. That will tell you if you need to make an astig adjustment."



"the question is HOW MUCH MOVEMENT or what KIND of movement am I looking for???"



I adjusted the pot and going in one direction the crosshair would blurr (or flair) to one side and then when i moved the pot in the other direction, that blurr went away, the pattern focused and then it blurred (flaired) to the other side of the crosshair lines. The main lines of the crosshair did not move but it did flair to one side or the other depending on which direction I was moving the focus pot.


Since I've never seen this done before I'm not sure what to expect here.


Thanks

Jim
"During the mech setup, after the raster, vid image and test signal are centered on the CRT, one of the steps is to turn the green focus adjust pot and see how that affects the focus and most importantly see if the green crosshair test pattern MOVES. That will tell you if you need to make an astig adjustment."



you only need to make an adjustment of the astig when your dots arent perfectly round or the vertical or horizontal flare isnt even on both sides of the crosshair.


if you have to change the astig.here is the procedure.firslty lower the brightness and put the contrast on its max.by doing this you can see the difference in your astig adjustment.set your midpoint focussing to 0.


first bring up the "dot" pattern.


now adjust the 2 pole magnet(if your facing the projector with the tubes in front of you)there is the 4 pole then the 2 pole(one right at the back of the tube where the neckboard is).


adjusting the 2 pole magnet:by moving the ring around the tube adjusts the direction of the beam while spinning the plastic handle on it will alter the deflection.in other words,adjust the 2 pole until (when using the dot pattern)the flair is equal both horizontally and vertically.



next is the 4 pole adjustment.first bring up the "dot" pattern.set midpoint focussing to 100.


adjusting the 4 pole magnet:by moving the ring around the tube adjusts the direction of the ovalness of the dot.eg.distorting the dot by making it looked streched.by spinning the plastic handle will change the amount of ovalness that the dot has.ie.from bolb to a ferfect sharp round dot.basically do this until you have a nice round sharp dot.

"the question is HOW MUCH MOVEMENT or what KIND of movement am I looking for???"



i dont know exactly what your saying there by saying how the crosshair pattern moves.when you focus with your G1 and G2 screws or the focus pots it will "move" due to being either focused or blurred.it should not literally move the actual crosshair.



regards,

luke
 

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Jim, maybe you should clarify this point in the Doc.

I thought it was clear, but I suppose if you have never done this it may not be. The focus procedure is a simple trick, actually. A quick shortcut to see if things are properly lined up. The same thing happens with the static convergence. If things are wrong, a left-right movement in the static menu may actually move the image diagonally, etc.

So you see, to make your life easier, this is a quick trick to check the alignment.


Marc
 

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Discussion Starter · #5 ·
LUKE,

Thanks for the clarification. I've been doing this astig adjusting this evening. Now that I feel comfy that I won't electrocute myself its much easier to do. :)


My question about HOW MUCH MOVEMENT was based on other posts that said the crosshair lines should not move but should only blurr when I adjust a focus pot. Since I have never done this astig adjustment before I wasn't really sure what "movement" meant. So I was just trying to get some clarification so I could recognize what to look for. I understand now.


When I blurr the crosshair I'm looking for even amount of flair on both sides of the crosshair lines. I wasn't getting this.


If you look in the thread in this same section, entitled NEC Mech Setup Procedure you'll see that Tinman and I are trying to get a procedure together to help us newbies. If you don't mind I think I'll add your comments, OK??



I'm not sure I understand what the 4 and 2 pole magnets are. Spinning the handle???????? What handle????


On my 9PG+ I have 4 rings back there, in two pairs. Each of these 4 rings have tabs on them. There are NO handles.


I did all adjusting on these while in the course dot pattern. I noticed one pair of rings moved the dots around and one pair of rings changed the shape of the dots.


TINMAN,

Yes once I have a good feel for this astig stuff, I'll update the procedure since its not clear enough right now.


Geeeez, I'm learning lots.

Thanks Guys.

Jim
 

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Yes, the tabs are the handles, or whatever you want to call them. It should be noted that the astig rings are fragile. If a "tab" gets broken off, the ring is useless and must be replaced. So a gentle touch is needed.


Marc
 

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Quote:
Originally posted by Feathers
LUKE,

Thanks for the clarification. I've been doing this astig adjusting this evening. Now that I feel comfy that I won't electrocute myself its much easier to do. :)


My question about HOW MUCH MOVEMENT was based on other posts that said the crosshair lines should not move but should only blurr when I adjust a focus pot. Since I have never done this astig adjustment before I wasn't really sure what "movement" meant. So I was just trying to get some clarification so I could recognize what to look for. I understand now.


When I blurr the crosshair I'm looking for even amount of flair on both sides of the crosshair lines. I wasn't getting this.


If you look in the thread in this same section, entitled NEC Mech Setup Procedure you'll see that Tinman and I are trying to get a procedure together to help us newbies. If you don't mind I think I'll add your comments, OK??



I'm not sure I understand what the 4 and 2 pole magnets are. Spinning the handle???????? What handle????


On my 9PG+ I have 4 rings back there, in two pairs. Each of these 4 rings have tabs on them. There are NO handles.


I did all adjusting on these while in the course dot pattern. I noticed one pair of rings moved the dots around and one pair of rings changed the shape of the dots.


TINMAN,

Yes once I have a good feel for this astig stuff, I'll update the procedure since its not clear enough right now.


Geeeez, I'm learning lots.

Thanks Guys.

Jim
yeah sure you can add my comments.sorry when i said handles i meant the TABS.


the 4 rings are the astig rings alright.im not too sure about NEC projectors although i do have a nec 6pg.im more knowledgable with my 1292.


(i looked at mine)im guessing the 4 rings are the 2 and 4 pole magnets.so for the 2 pole adjustment i would say one handle adjusts beam deflection while the other instead of spinning the little handle like it does on the sony,you use the other handle for for the direction of the beam.do you understand?


i will get clarification on this soon for you.



luke
 

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Thank you all this has been enlightening (yeah it is a pun and also a kudo)
 

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ok, after a quick check on my 6pg by moving the tabs on the 4 pole magnet the first(facing the projector from the front of the tubes)tab moves the direction of the beam while the other adjusts the ovalness where it makes the dot look like a blob or blurry.remember like in guy kuo's thread,under focus it before adjusting the 4 pole magnets.also set midpoint focussing to 100.this is all done by using the dot pattern.


while for the 2 pole magnet,also like in guy kuo's thread,when you adjust the 2 pole magnet like it states,you have to over focus the dot.in other words,have a flairing around the dot with a bright central core.using the dot pattern(not crossshair which i edited in previous post)and midpoint focussing set to 0.the first tab moves the direction of the deflection and the 2nd one change the amount of deflection.so basically your getting the bright central core in the middle of the flairing.


by adjusting both pole magnets its easy to see what does what in the real world.


also i use the focus pattern or "H" for doing this procedure(especially for the 2 pole magnet).you can definatley see the difference when using this test pattern although its more finer and get better results with the "dot" pattern.


perform the 2 pole magnet adjustment before doing the 4 pole magnet adjustment.



luke
 

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After reading this and after palying with a 6Pg this week I now want to get back inside my 1031Q and see if I can make it even better.


I am on working on a project that may have me comming home with a 6PG. I can say I really like the inerds of these NEC's as they have a little "handle" on the rings for adjustment and a long metal "handle" on the main positioning coil to square up the raster. You dont have to get inthere and grab with your hands like in my SONY. So for this I am envious of you NEC guys. I hope Ill be one of them in a few weeks :)
 

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also to point out that the two tabs on both the 2 & 4 pole magnets are interactive.
 
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