Found a Sony document that says those Permalloy strips have disk magnets.
http://www.scribd.com/doc/24405455/TVP09-RA-3-Chassis
I'm more inclined to believe documentation from manufacturers.
Ok, that document also says that they will have metal or ferrite to impact the magnetic field of the yoke. So it sort of contradicts itself... Have to keep looking.
Edit: Permalloy strips can be magnetized.
You are confusing things here. That document is talking about disc magnets AND permalloy strips. Two different things.
Widegeek description of Permalloy:
This metal magnetizes and demagnetizes quickly and evenly, in contrast with other metals which exhibit magnetic properties. Various factors can influence the magnetic permeability of the permalloy, including the humidity, temperature, strength of the field used for magnetization, distance of the magnetic field, and so forth. These variables can be tightly controlled as needed by people working with the metal so that they can achieve the desired results for the application in which the metal is being used.
Sounds exactly what is needed and reached with the strips we are talking about. Very interesting and a good find because I've always wondered what kind of metal it was (I've been thinking of making these strips myself, they are getting rare!).
The magnets mentioned are more like the one's find inside the yoke I guess. Also note that the manual is for flat screen TV's, what's make it different from our old-fashioned round tubes. However, Kent, you could experiment CAREFULLY with a (weak) magnet to see if it helps.
As mentioned before, Rich was production engineer on the G07 line of monitors AND now has his own company in monitors. He also gives (or gave) group sessions to instruct how to do complete monitor set-up (convergence). He knows his stuff.
Also, in my book, magnets stick to (most) metals. The strips don't.
Kent: no, those strips have nothing to do with the purity. They are only for edge/corner convergence. I made a video about how they work here:
http://www.youtube.com/watch?v=QYB1L8AIeq4
Note that this is the LAST step you do on a complete convergence job.
First: How did you do the demagnatization ? Did you just do the front of the screen or the entire tube (from the back). Could be worth a try. Do it while it's in the set-up you are going to converge it in, because as soon as you move it it may already change again. This is especially true if it is powered on ! (I have very often moved a running cab, saw the colors changed. After a power down and (automatic) degauss by the monitor itself this usually is gone.
Did you try tilting the yoke sideways or up/down to get the green pure all over the screen ?
Check out the document that VectorJunkie linked to, it's an interesting read. That also has a picture of what I mean on page
It's been quite some time ago I worked on it, but I seem to remember that I had to do this to get purity right on the low-res 25" I was working on.
To be clear: I have NOT done complete convergence on my own Amplifone 25". The main convergence (center) was fine when I got it, it only had the shown problems on that video.
The one I did try to converge was that Amplifone set-up with a Low-res tube (WG ?)
Never got it perfect though. I too felt like I had to move the yoke more towards the screen than was possible. I still think it has something to do with the angle of the tube.
