AHD camera-system image interference
Improper cable and connector connections
BNC connectors are not properly attached as per the video guide, or contact resistance is occurring somewhere. Make sure connectors are properly joined to the conductors and re-check existing routes.
The socket is not properly grounded
The whole system must be connected to the same phase of the mains. If cameras are powered from a different source than the recorder, you may end up on a different phase, which can cause interference and is also a potential hazard from static surges that can damage the camera system.
A basic prerequisite for a stable, quality image is good grounding of all powered system elements. This may not be met if the system is powered from old mains that don't meet current standards. To rule out the fault we recommend testing the camera system on a different mains (different building).
Cabling issues
As mentioned above, virtually all image issues are caused by cable runs. Consider the most common causes:
- Cabling is poor quality and doesn't meet the RG59 standard.
- Rodents or other pests damaged the cabling.
- Water enters the cabling and connectors due to poor installation.
- The route runs parallel to high-voltage wiring or other source of EMI, which can cause coloured lines, stripes and ghosts — interference.
- Stray currents from other appliances (fluorescent lamps, fridges) can be present in the high-voltage grounding and cause interference.
Solution
Solving these image-noise issues is usually very difficult because their overwhelming majority is caused by external influences specific to one location or one camera (channel). If you experience problems, you'll have to look for the cause and experiment with replacing cabling, cameras and their placement.