Hi i have same problem maybe.
Cable is STP 4x2xAWG23, Category 6A, 550 MHz, LSOH, Euroclass Eca
I used videoBalun HD (is for tvi cameras) and in picture have color bar :/ But this is no problem for ground because ground problem is horizontal lines ... Picture is great and clear but only this color bar scrolling, only one scroling. Is hikvision 5Mpx cameras TVI ...
Distance is cca 120m
https://youtu.be/bMv5-bRfejI