I've posted measurements of the degradation that cables does to video signals before; see here, but I was grabbing a couple of screen caps for an industry colleague and here they are.
My pals at Lindy (who I buy lots of computer connectivity parts from) sent me a bunch of engineering samples of 3G-capable SDi parts; DAs, fibre transceivers etc. from one of their OEM manufacturers in the Far East. For very modestly priced pieces they were excellent. The eye-pattern (above) is the output of their re-clocking [...]
Return loss is the loss of signal power resulting from the reflection caused at a mismatch with the terminating load or with a device inserted in the line. It is usually expressed as a ratio in decibels (dB); where RL(dB) is the return loss in dB, Pi is the incident power and Pr is the [...]