computer monitor as cctv monitor

Possibly. CCTV, will normally be composite video, at 60Hz 'interlaced'. Now _some_ older computer monitors may (just) be able to work down to this sync rate. On these all that would be needed, would be a composite to RGB decoder. However most monitors will not go down to this low a sync rate, and then at the minimum, a 'frame store' will be needed to generate an output picture at double the line rate coming from the camera. Such units are called 'scan converters', and are relatively complex.

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You can buy a gadget to convert the 64 uS, line, 50 Hz PAL field to something the monitor can handle:

Frank Raffaeli

And, this is far less, than you'd even be able to 'part build' such a system for...

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