tmcc signal adjacent to track?

The tmcc track signal consists of two parts, the track, AND your house wiring.  Most issues with signal reception have to do with problems picking up the reference signal on the house wiring.  If you are experiencing problems with the house wiring side AND you want to try an auxiliary source/wire then use Dale Manquen's procedure of pulling the reference signal off of pin 5 of the command base data port.  Your other option is to try and figure out why the command base isn't connecting properly to the house ground wires.

 I guess I'd need to add all the details. The TMCC brick can work quite well all around if I connect it at my main distribution panel. However if I do, the dcs system crashes. I have found that I need to add the TMCC signal at the farthest point of the layout away from my TIU's and DCS engine yard. When I connect it there both systems will work but each is weakened somewhat. I simply gave up on running tmcc two rail at the same time as DCS.

TMCC does use earth ground for signal prpogation under normal circumstances.  You may want to test this under careful controlled conditions.  Use a cheater (2-3) prong converter between the wall wart power supply and the electrical outlet.  Use pin 5 on the command base computer port for the reference plane.  You may need to experiment with which outside rail to use for the track antenna for the command base.  Carl Tuveson does use two rail tmcc but not with dcs.

Hi Joe,  I made the post about laying a wire next to the track.  TMCC requires no connection to the actual running rails in order to work.  The outside rail is used as a convenient antenna that requires no extra wiring be added to the layout.  Lionel originally believed that the TMCC signal only existed very close to the antenna (track rails).  Such is obviously not the case.  I can use alligator clips on a small transformer to run a TMCC loco on my work table which is 6 feet from the layout (as long as the layout's Command Base is powered). 

It would be really interesting to build a layout with a single wire running the circumference of the layout (buried under scenery or something) and hook the TMCC command base to this wire instead of to the track.  Given my experiences, I believe that TMCC locomotives would function very well. 

If the layout has multiple levels, I would run this wire around the lowest level only and not run any TMCC wires on higher levels.  This design might eliminate the phenomenon of TMCC locos being saturated with signal from above and below when passing under tracks that run overhead.  With the single separate wire approach, TMCC signal would always come from below and the earth ground reference would always be available above.

 Thanks Bob, I've got to try this before I can the whole idea. The two systems don't get along on two rail for me the way I've wired my layout. Having the signal off the rails might help??

Have you tried just placing the TMCC Command Base on the outside next to one of the rails. Sometimes the signal is so strong that you don't even need a direct connection. We saw this happen while doing some TMCC demos at a train show. We forgot to connect the base to the outside rail but the single was picked up by the engines anyway.

I wonder why there would be interference with the DCS signal since the frequency is not even close. Maybe something else is interfering.

 I don't know. Most people told me there should be no problem. Then Carl T says I should move the TMCC base further away. I bet two rail poses some kind of issue with one of the DCS signal paths hitting the TMCC. All I know is when I unplug the base, DCS is fine.

Normal three rail usually has little or no issues as DCS signal injection is on the center rail with the return on the outer rail(s).  TMCC uses the outer rail as one half of the antenna and the homes ground wires as the other half.  

Is there any difference in system behavior depending on which rail you connect the tmmc command base antenna wire to? If you swap that wire to "the other" rail does the behavior change?

 Would you know that I never thought to switch the rail?? My DCS has a + on the inside that I keep that way to keep things easy. I connected the TMCC to the - outside rail. That could be another test to perform. Maybe they would coexist better?? I never made Carl's suggestion of a signal enhancer for TMCC as it was stronger than the DCS was when together.