My Trinitron monitor actually had two of those stabilizing wires. They were very thin, much thinner than even a single scan line, but you could definitely notice them on an all white background.
Screens 15" and below have one wire located about two thirds of the way down the screen, while monitors greater than 15" have 2 wires at the one-third and two-thirds positions.
My Trinitron monitor actually had two of those stabilizing wires. They were very thin, much thinner than even a single scan line, but you could definitely notice them on an all white background.
Apparently the dividing line was 15 inches:
https://en.wikipedia.org/wiki/Trinitron