Picture distortion occurs in many installations. This can be caused by the following: Ground loops, mains pick up and cross talk.
Ground loops occur when the earth potential at the camera is different from the potential at the monitor. This difference may only be a small voltage but it can cause large currents to flow through the shield of the coaxial cable. The Ernitec BGVS Series breaks this circuit only allowing video and camera control signals through. These large currents will cause picture distortion and safety problems if they remain.
Cross talk occurs when a cable carrying high frequency signals lies next to the video cable. This is often seen as diagonal lines passing across the screen. Sometimes they come and go, the Ernitec BGVS eliminates most of these as it only sees the difference between signals connected to it.
Mains pick up occurs when coaxial cable runs in parallel to a power cable. A sinusoidal voltage develops on both the shield and the video core. This is often seen as a "hum bar" passing down the screen. Because the Ernitec BGVS Series only sees the difference between signals connected to it, the video is passed without the hum.