Coaxial cables for digital video

摘要

Analogue distortions produced by cables affect digital signals in roughly the following order of importance: 1. Frequency dependent cable attenuation 2. Signal reflections 3. Phase distortion 4. Noise introduction When automatic equalisation is used to combat item 1, any typical Serial Digital Video Interface (SDI or HD-SDI), will still exhibit a failure "cliff; which will be approached very rapidly. Indeed, the difference in cable length between that producing a trivial error rate and one producing an unacceptable mess, can be as little as 15 metres in several hundred metres of total length.