I've got a few NTSC security cameras I'd like to set up around the perimeter of the house. They output standard NTSC video and require 12V for power. I was hoping to power them and take video off the same cable, but I haven't been able to figure out a slick way to do it yet. Structured cable isn't all that expensive but if I could stick with standard RG59 or RG136 I think that'd be best.
Unfortunately it's not like injecting power into RF signals; NTSC video sits around 1Vp-p and has high frequency components to it so it's not as simple as just using a DC blocking cap. Has anyone done something like this before and what kind of success have you had?