Hi i have installed 4 Hikvision turbo 5mp cameras, They are run off 4 seperate 12v power supplies. The video is transferred through one shielded cat 5 cable with baluns up to the longest camera which is 240 metres length. The first 2 cameras work fine with no interference. The 3rd camera works fine with no interference until you turn on camera 1 and 2 and then it starts to pick up some minor interference (very minor interference not too concerned about). camera 4 has always got interference in the form off a scrolling vertical colourful bar and general fuzziness across the whole picture, and when you turn on camera 1 and 2 the video from camera 4 only displays in black and white (not IR mode) its just so dull its black and white. Additionally on the Dvr you can change the picture quality on the cameras between 4 and 5 mp and when you change the picture quality for camera 1 and 2 up to 5mp the interference on both camera 3 and 4 is crazy you get colourful bars flying all over the screen and you can barely see a picture. Anyone have any ideas to help?