Thin vertical lines with black or white spikes on your CCTV are the symptoms of interference from a camera, shared terrain or an uninterrupted supply of power, also known as UPS. Monitors can show lines that jump side by side or move slowly from one side to the other. Follow some CCTV troubleshooting techniques to observe the sharpest details and remove the vertical lines.
- Unless you replace all types of square wave UPS with a higher quality UPS, vertical line interference will be difficult to eliminate permanently.
- Replace the DC-powered cameras with those powered by AC. Those of CC can not be blocked on the line, while those of CA have a line blocking function. Line lock refers to the ability to lock cameras together. This function tunes the vertical margin pulses based on the 60-cycle AC frequency. Adjusts the phase control on each camera to match the pulses vertical intervals and eliminates vertical line interference.
- Reinstall the camera if it and the UPS are also grounded. An induced ground loop can occur when the UPS power is transferred from the coaxial cable to the cameras, especially those powered by the DC. This is because the negative power supply cable in the camera and the coaxial shield are the same. An induced ground loop causes interference in the vertical line.
- Replace the types of square wave UPS with the quasi-sinusoidal, semi-sinusoidal wave or a USP type sine wave. The square-wave UPS power supplies have frequencies that go in the Kilo-Hertz, or 1000 Hz, and Mega-Hertz, or 1000,000 Hz regions. This extends well beyond the video frequency range, and so It causes interference.