How to Troubleshoot Vertical Lines That Are Visible on a Security Camera
Jagged black or white thin vertical lines on your CCTV are symptoms of interference from a camera, a shared ground or an uninterrupted power supply, also known as UPS. The monitors might show lines that jump from side to side or move slowly from one side to the other. Follow some CCTV troubleshooting techniques to observe the crisper details, vertical line-free.
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Instructions
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Replace DC-powered cameras with AC-powered cameras. DC-powered cameras cannot be line-locked, while AC-powered cameras have a line-locking feature. Line-locking refers to the ability to lock cameras together. The Line-Lock feature times the Vertical Interval Pulses based on the AC's 60-cycle frequency. Adjust the Phase control on each camera to match the Vertical Interval Pulses and remove vertical line interference.
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Reinstall the camera if it and the UPS is also grounded. An induced ground loop can occur when UPS energy is transferred from the coax cable to the cameras -- especially DC-powered cameras. This is because the negative power supply wire at the camera and the coax shield are the same. An induced ground loop causes vertical line interference.
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Replace square-wave UPS types with quasi-sine wave, semi-sine wave or sine-wave USP types. Square wave UPS power supplies have frequencies that go into the Kilo-Hertz, or 1000 Hz, and Mega-Hertz, or 1000,000 Hz, regions. This extends way beyond the video frequency range, and therefore causes video interference.
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Tips & Warnings
Be sure to use AC power supplies with AC cameras, as vertical line interference not only can come from DC cameras, but also DC power supplies.
Unless you replace all square-wave UPS types with a higher quality UPS, vertical line interference will be difficult to remove permanently.
