CurtPalme.com Home Theater Forum

outwest · Joined: 17 Dec 2006 Posts: 212 Location: Honolulu

Some time ago, there was a discussion about astig rings and the possibility of making them or enhancing them and someone suggested showing the magnetic field with some iron filings. The idea was interesting and I was curious to see what the experiment would show. I don't think any pictures were ever posted, so I decided to give it a try. The only rings that I had available were some parts that I had saved from some Sony 10XX machines. The rings were placed under a sheet of thin white paper and dusted with powder from a Magnaflux kit.

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

Yeah i ahve been thinking about making my own 6 pole cpc magnets. CMJ did this by finding the feild as you have shown above then taking the one magnet out of the 4 pole that is "dead" with no magnatism then he matched the field from a know 6 pole configuration by placing rare earth magnets on those places to magnetize the rings. Not sure if all cpc rings have the same magnetism in the same set. What i mean i wonder if the first middle and last magnets all have the same pattern .

Athanasios

tse · Joined: 03 May 2006 Posts: 1014 Location: Sweatbucket, Fl.

Wow, that's really cool. Looks like that is why stig rings are called four pole. The beam centering (flair) rings are two pole. They would show two of the groups spaced 180 degrees? The six pole rings (triangular spot correction) would show six groups spaced 60 degrees apart?

Scott

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

Joust · Posted: Wed May 07, 2008 12:55 am Post subject:

i did the same with a 2 pole

Joust · Posted: Wed May 07, 2008 12:58 am Post subject:

i really believe that we can do this with some of the unmagnetized ones by making a jig that will hold some of those small rare earth magnets in a regular geometric pattern if 6. then place the astig rings in the middle of the field.
as you can see, its easy to test the results.

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

Joust · Posted: Wed May 07, 2008 1:08 am Post subject:

hey that wasn't me.
I'm a hacker too Smile

I'd try it but I have a million other projects on the go right now. all i need are some rare earth magnets.
i have another Marquee to build up too .
and I'm building a truck.
and work is hectic and hellish.

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

1031 · Joined: 22 Mar 2006 Posts: 657 Location: Finland

That paper/iron powder works also if you have teared down those magnets..and forgot that what what was 2-poles and 4-poles Neutral

Who didt that Question

Me

outwest · Joined: 17 Dec 2006 Posts: 212 Location: Honolulu

Joust

Your picture is interesting. Two poles are clearly visible, but the entire ring shows an effect on the iron filings and it also seems like there is a magnetic field within the ring. I have no idea what it means, but it is very different from the very clearly defined four areas on the Sony rings.

Joust · Posted: Wed May 07, 2008 12:18 pm Post subject:

it is the magnetic field in the center of the ring that affects the electron beam of the CRT. if there was nothing there, it would have zero effect on the beam. the 4 pole has much more magnetic stuff going on in there.
what I did was put the filings on, then tap the paper lightly. the filings move around and line up along the magnetic lines better.

JustGreg · Joined: 07 Mar 2006 Posts: 3098 Location: Kenosha, WI

**AnalogRocks** · Posted: Wed May 07, 2008 5:52 pm Post subject:

**AnalogRocks** · Posted: Wed May 07, 2008 5:53 pm Post subject:

Has anyone tried stacking rings for stronger magnetism?

garyfritz · Joined: 08 Apr 2006 Posts: 12088 Location: Fort Collins, CO

perisoft · Joined: 29 Aug 2007 Posts: 2920 Location: Ithaca, NY

OK, noob question... how does this relate to the astig rings on the barco, where there are two rings that can be rotated around the axis of the tube, but each has two components which can move relative to each other by means of a knob?

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

Joust · Posted: Fri May 09, 2008 3:47 am Post subject:

outwest · Joined: 17 Dec 2006 Posts: 212 Location: Honolulu

Athanasios

Your idea of the ring around a tube of paper is cool. I will try to see if I can make somehing up that will show something useful . It might be tricky to get something workable that I can get a picture of. It might take me a couple of days. I am up to my clavicle in alligators at work right now and I also have a mainland visitor.

I have been thinking about the picture of the two pole ring that Joust posted. It is not at all what I would have expected. The four pole Sony rings fit my mental image of what they would be. I expected the two pole to be very similar, but with just two areas of magnetism. The filings on the Sony rings seem to come up and curve to the outside of the ring like the north pole was on one side and the south pole was on the other side. My vision is that the electron beam goes down the center and is positioned or shaped by the influence of the surrounding magnetic fields. It seems like the definite magnetic field lines within the ring in Joust's picture would mess up the beam, like sticking one's finger into a stream of water. I am operating from a position of complete ignorance here!

Can anyone post a picture of a six pole ring? I could do it if someone wanted to slip one in an envelope and mail it to me. I would return it. I could send a small packet of iron powder to someone if that would be helpful.