[roommaker]

Hello,


While setting it up my sony 1271 i was performing astig kallibration. I have read the whole technical manual and also nearly all threads to get info how this is done.


I have followed all instructions exactly, but while defocusing the electrical focus und trying to adjust the highlited beam in the center of the flair i have no succes. In the attachment picture i have given you a impression how the picture looks like.


I know all the functionallity of the 2,4 pole magnets and how to use, but it is impossible with the green tube to center into the flare.


If vertically i have centered the beam horicontically it is out of order and so on.


I yust don´t know any further what to do.


regards peter

 

[Brian Hampton]

Hey,


I think you forgot to attach the picture.


I have a 1271 and I find the astigmatism to be a tricky adjustment (and we always have to mention the danger aspect as well) but I can do it. I have found that trying it a few times seems to help. It's a kind of skill and you can get better at it with practice.


Good Luck,


Brian

 

[roommaker]

here is the picture

 

[roommaker]

Hallo Brian Hampton,


it is really wonderful to me that you answered so fast.


I know that it ist tricky, but the manuals and all other postings i have found (an shurely i have read very many postings in the searchlist) stop when there is the sentence....


...defocus to the left take pole 2 and adjust so that the beam is in the center of the flare....


I couldn´t find even one post or manual which definitley shows this process. Of course with the knob and by rotation.


So please share me something of your experience. That would be a great joy to me because my green focus is yust terrible.


Of course optical focus i have done.


Very thanks to everyone who gives yust a hint where i canb search further.


Sorry: I had to cut off the picture first therefore the delay.


regards peter

 

[Brian Hampton]

You have the service manual right?


The part of the adjustment is only half of the astigmatism. The other half is rounding the spot and that's the more difficult of the two if you ask me. The two affect each other though so maybe on or the other is off.


My experience has been that the first or second time I did it I thought I got it right. The next day I notices the blue was really very off. So, I did it again. I find it difficult. I would say it's best to be very awake (not tired) when trying this.


If I can think of a way to help you with this more specifically, then I will.


-B

 

[roommaker]

Hello Brian Hampton,


your are right of course that there is also the need "to circle" the dots in the dot grid test pattern. Of course i also performed this. I only posted the picture to show where my problem is.


The dot test pattern i could configure that the dots (halo) became perfect round. But in the dot pattern i saw also that the enlightened focused point was exactly at the border of the circle an not at the middle.


I also realized that both settings affect to oneanother but the problem is what is a systematic way to get it perfect. I yust can try some more times. Without theoretical help i will never get it right.


Therefore my urgent cry for help


regards peter


P.S. Thank you very much for your reply !!!!

 

[Guy Kuo]

You should be aware that the astig magnet rings are in pairs which are juxtaposed. In order to perform the adjustment you rotate the two rings of a pair in opposite directions relative to each other as well as together about the axis of the tube neck. It sounds like all you have been doing is rotate them together about the tube neck.


The two pole rings when moved in opposing directions alters how far the center bright core is deflected. Rotating the two rings together changes the direction of the deflection. Do these with the beam overfocused to create a bright core with flare.


The four pole rings when moved in opposing directions changes the degree of elongation. Rotating the four pole rings together changes the axis of the elongation. Do these with beam underfocused to create a blob.


Definitely start your journey down the astigmation adjustment road by using a dot pattern rather than a center cross. It is much easier for a beginner.

 

[roommaker]

Hello Guy Kuo,


first of all very thanks to you. Not only for your reply but also for your very good manual about setting up a CRT, which helped me very much.


Of course i also rotated the knob to rotate the two poles in opposite directions. I also proved whether they really rotate against each other.


But my problem is that even in your manual it is said, that the focus has to be adjusted in the center of the flare.


This centering is just impossible. Like shown in the picture the centering can only be performed vertical or alternatively horicontically but not both at one time.


It would be a great help to me to know wheter it is really possible to adjust the picture like i have shown as the desired image when defocused ? Or does the picture not exactly look as i have shown ?



Please clarify to me.


Best regards peter

 

[Guy Kuo]

Image 2 seems to have the flare exactly centered in both horizontal and vertical directions, but frankly the small scale of the image and use of a center cross image makes it harder to see what is actually going on.


If a diagonal deflection of the flare and bright center point is needed rotate the small knob about the axis of the tube neck rather than just spinning the little knob about its own axis. It sounds like you are only spinning the knob but never making the knob go around the axis of the tube neck to vary the angles of the rings together. Spinning the little knob on its own axis moves the rings in opposing directions. Grabbing that knob (and not spinning it on its own axis) and using it to rotate both rings together around the axis of the tube neck also needs to be done.


AGAIN, I reiterate it is much easier to understand and do this if you use a dot pattern rather than the center cross as in your images.

 

[Guy Kuo]

Here is a pict showing one type of CPC magnets assembly. They vary in actual physical knobs, tabs, locking mechanisms, but they all have rings pairs which can be moved either together or in opposing directions.