John:
Sorry - What I meant was the ground wire (command signal wire?) that needs to be connected from the command base U post to the track ground or to the powermaster/TPC. This is how the command base sends its digital signal to the track then to the locomotive. Lionel video says that if you have two command bases attached together you only attach one wire from one base to track ground. If you attach two wires one from each command base the signals will cancel each other out and you get no command control. What I can't find is any info on having one command base but two powermasters/TPC with their own power sources separately connected to different blocks of track electrically isolated from one another. I am not sure if I have to connect only one wire from the command base to one of the powermasters/TPC or to both. I have a feeling that based on what you said about the common ground for all track that one wire from the command base may be enough. Though it is highly unlikely to happen I hesitate to experiment for fear of blowing up a $500 locomotive so figured I had better ask first.
Joe
