Maximum transmission distances for digital video cables
The serial digital interconnect standards are designed to operate where the signal loss at half the clock frequency does not exceed these approximate loss values:
|SMPTE 259M (PAL, widescreen):
||Maximum length = 30dB loss at half the clock frequency
|SMPTE 292M (HDTV):
||Maximum length = 20dB loss at half the clock frequency
This provides a method of defining the maximum calculated length of cable for satisfactory signal transmission1. Interfaces such as connectors and patching may alter the overall "end-to-end" parameters as the cable is only one part of a signal path, and this also assumes installation of cables within their minimum bending radius limits and without crush effects of tie-wraps and other cable bindings that locally distort the construction profile. Having mentioned "the disclaimers", the values shown below are a reasonable guide to what might realistically be expected in a typical professional installation.