Tektronics WVR7100 & 6100 remote cables - we put in a load of these waveform monitors and I'm a big fan - you fundamentally can't get a more accurate video signal analyser. Anyhow - they come with dire warnings about how you can extend the optional control panel - essentially the manual suggests you should ONLY use the provided 8m cable - kinda daft when most edit suites are more than 30m away from the machine room!
So, here is the pinout for doing it over cat5 - pin 9 is the ground and pins 2 & 8 are +Vcc

9 - brown
8 & 2 - brown/white
1 - orange
3 - orange/white
4 - blue
5 - blue / white
6 - green
7 - green / white

I've tested it to 50m and it seems fine. In my case it is going via a patch in the machine room, a wallbox and a patch in the suite.