said by nunya:
You'll probably have to come up with a special order power supply to get the voltage just right, or at least within tolerance, on the far end.
Or do what cable does and shove 60 volts ac down the coax, then either rectify to the DC voltage needed or use a 1-2 ratio transformer to bring it back up to 120 volts ac and power locally from that.
"It is sobering to reflect that one of the best ways to get yourself a reputation as a dangerous citizen these days is to go about repeating the very phrases which our founding fathers used in the struggle for independence." - Charles A. Beard