When connecting my RasPio to my tv (rather old, but not tube tv anymore), I get this weird flickering everywhere on the screen where clean, thin lines with big contrast are present (including fonts). I already tried increasing
/boot/config.txt up to eleven, but I'm getting no visible change. I know that my cable as well as my television are able to display clear lines as I'm using both with another device that works perfectly.
Can someone tell me how to solve this, or at least name me the problem? I'm using raspbian on the Raspberry Pi 3 Model M.