@Bob posted:Also NEVER, NEVER, NEVER connect AC common from your transformer to earth ground unless you want to completely kill the TMCC signal.
@Bob posted:...I copied this from http://www.trainfacts.com/trainfacts/?p=298
That is not a direct connection, but instead, a capacitive coupling in the TMCC base. You can see in the schematics that there is no direct connection between the house ground and the layout through the "U" output post.