[old_tv_nut]

The way to think about metal cone mono CRTs is to note the effects of degaussing metal cone color CRTs. Degaussing the color CRT results in beam landing deviations on the order of fractions of a millimeter (the spacing between color dots). It does not produce any noticeable change in the geometry of the image. So, in a monochrome metal cone tube, it would produce no noticeable effect and is not needed.