This is just one source for Video Isolation transformers and isolation amplifiers.
http://www.21best.com/21_best/electronic/security/video/filters/for_sale_.html Another approach is to isolate the video source that is causing the hum bars, from the local ground. THIS DOES NOT MEAN CUT OFF THE GROUND PIN! If it is a camera, mount the camera base on a piece of wood. If it is powered by a plug in power supply, check to see if there is a ground lift jumper or switch.
Verify that the earth grounds at the outlets feeding the video equipment are connected to the same grounding system and they are at the same potential to each other.
LarryC
