[miniman82]

I have several books and read more than a few HO tube data sheets that talk about it and what causes it, but never seen it in real life on any of my sets. But then I'm a nazi when it comes to horizontal circuit set up and adjustment, so maybe my being anal about it is why it hasn't come up. A few data sheets I've read (for compactrons) state that applying a small positive (~30 volt) potential to the beam forming plates can counteract the phenomena, but obviously this is not possible in tubes having the beam forming plates tied to the cathode. I've heard of the ion trap trick as well, and even encountered a chassis with a seemingly factory installed magnet around the HO tube. Common wisdom these days says go tube rolling till you find one the chassis likes, but not everyone has piles of sweep tubes laying around their house.