i have an old arcade game with a bad monitor, blown out flyback that is unobtainable. . tough to find a working 13 inch cga unit, and harder to find one compact enough to fit . anyway, ive tried using a cga to vga converter board ( GBS 8200 ), its commonly used and has worked well in the past. im using a 13" vga flat screen .

the vga has horizonal jitter, quite bad. no way to adjust out. somebody suggested plugging a spare vga cable into the vga input on the converter board. that reduced it 90%, but on a reboot its back , and cant get rid of it. the game works nicely when hooked up to a spare 19" cga crt. i also tried a vga crt, same jitter.

im thinking the added cable adds a load that stabilizes the horz sync, and maybe there is a way to make it more stable? there is only h sync out, no vert. vertically, there is no jitter

thanks