Two Way Hourglass Bends on My KCS47

[Penthode]

The barrelling is what is known as pincushion. It is exacerbated by the geometry of the tube eg wide deflection angle and flat screen. I don't that is the case here.
What I think your case is due to is magnetization of the steel CRT bell. The beam as it deflects to the edges of the raster image is likely being affected by the magnetism of the bell.
I suspect if you can degauss the CRT bell, the pincushion effect will disappear and the edges of the raster will be straight.

[Chris K]

Originally Posted by Penthode

The barrelling is what is known as pincushion. It is exacerbated by the geometry of the tube eg wide deflection angle and flat screen. I don't that is the case here.
What I think your case is due to is magnetization of the steel CRT bell. The beam as it deflects to the edges of the raster image is likely being affected by the magnetism of the bell.
I suspect if you can degauss the CRT bell, the pincushion effect will disappear and the edges of the raster will be straight.

How could that be done? A degaussing hoop I have seen others use??

There are a thousand Chinese made degaussing wands for sale on eBay for <$20 but they are all 220V