I was wondering following:
On lots of CRT's, the convergence is fine tuned with small magnets that are on a plastic strip with a sticky part at the end. Like the white "stripes" running from the center of the CRT on this picture:

My uncle mentioned that these can loose their magnetic fields over time, and thus causing misconvergence. We were talking about the vector monitor in my SW cockpit that show poor convergence on the left lower side mostly.
Any experienced people that can confirm this ? (Ken ?)
If so, how are these things officialy called and can I order them somewhere ?
Thanks !