Second command base or tie the loops together

Hi Frank,

Just add a second wire from the current Legacy base track wire post to the common (outside rail) of the second loop or to the common of the transformer output for the second loop. That will maintain your current separation configuration and provide to signal to the loop(s) that currently do not have it. There should be only one Legacy base for a layout.

I want to mention that there is a possibility of Legacy signal problem when an elevated has track the passes over a lower level track. Don't be concerned about it until a problem arises, like a loco on the elevated loop stuttering or stopping. There is a solution. 

The problem with a track over a track is with the engine on the bottom track. The upper track tends to shield the engines on the lower track from the signal in the air from the third wire ground house wiring which carries the signal. So the solution is, if you need it, is to run a ground wire under the upper loop. The ground wire can be small gauge and connected best from the pin #5 of the DB9 connector on the Legacy base. Alternatively, instead, you can connect the additional ground wire to the grounded screw on a wall outlet cover plate. 

FYI, the signal gets to the third wire ground in the house wiring by way of the ground pin on the base power supply plug.

FWIW, you NEVER want a second TMCC/Legacy command base driving the track on a single layout!  One track signal per layout.

GRJ, thanks. OK, certainly I shouldn't use more than one command base per layout. However, what confused me is since my levels are totally seperate is that one layout or two?

ChooChoo1972 posted:

GRJ, thanks. OK, certainly I shouldn't use more than one command base per layout. However, what confused me is since my levels are totally seperate is that one layout or two?

Well, let's put it this way.  I'd call it one, and having two command bases on a sizable run of tracks close to another set of tracks will have sufficient coupling to be a problem in many cases.  Since just connecting the outside rails of the "two" layouts together solves the problem and uses a single base, clearly that's the best way to go.

I found that just having a base on the layout in the room couples to a totally separate track on the workbench without any wire to the outside rails. It might be transmitted thru the house room wiring. No idea. I had to turn the layout base off to run a Legacy in conventional on the isolated test track.