My suggestion would be to contact CVP Products in Richardson, Texas and ask them -- they still support RailCommand products to some degree though they regard it as totally obsolete technology.
http://www.cvpusa.com
When you click on this link and their web site opens up, you'll even see a RAILCOMMAND tab at the top of their home page. They are usually good at responding to e-mail questions.
Boards as in the loco mounted receivers or boards as in the power supplies? It makes a huge difference. Inside the loco, fine wire is plenty - look at the wire used for DCC decoders, or the wire used to connect the truck pickups to the lighting boards in plain DC locos. Unless you are in O scale or larger, or are goign to put a receiver in a dummy unit and use it to power 3 or 4 powered units in a permanent lashup, #28 or so wire is plenty thick for connecting the power pickups and the loco motor. Also it's flexible and easy to route away from moving parts.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
That sounds about right. Most DCC dealers will sell chunks of 'decoder wire' so if you decide to get fancy you can use the DCC color code, which could make futre conversion to DCC easier. Red for the right rail pickup, black for the left rail pickup, orange for the + motor, grey for the - motor. Although if you have a lot to do you can probably buy a large roll of all one color from an electronics supplier like Mouser for the same price as a short bundle of DCC colors.
Thanks for the help, Randy. I will be using the color code as I go. I'd have a real mess if I didn't ! You can view the club layout @ mexicotrains.com . Have a great day !