thanks, it works for me and makes railway operation much easier. I don't pretend to know how the electronic gubbins work. I just use a short two core cable to supply power to the rf relay and 3 core cables to supply ongoing power and a switching voltage to each of the servo controllers. Each of the blue rf relays are connected as a simple switch on one leg and to the led's on the other leg. The servo controllers could be mounted in lineside buildings or any structure that is dry. i hope this helps, John
