TMCC isolation question

[4kitties]

Hi all, I have a problem that really has me scratching my head. I have an industrial spur on my layout that's controlled by an automatic reversing unit, which causes the train to run continuously back and forth from one end to the other. The loco is an Atlas O SW-1200RS with TMCC. Everything is fine until I power up my TMCC command base. Then, the next time the loco's reverse unit cycles, it "sees" the TMCC signal, goes into command mode, and waits for commands from my CAB-1. I have always used a separate power source for this spur, and that alone doesn't solve the problem.

My question is, if I isolate all 3 rails, will that do it, or will my loco still see the TMCC signal because it's picked up via the loco's internal antenna? If so, then I guess I need to use a loco without TMCC - or can TMCC be "turned off" on this model?

Thanks for any help,

Joel

[wrmcclellan]

Hi Joel,

There is no way I am aware of to "turn off" the TMCC and regardless of how well you try to isolate the rails of the siding, the loco will likely "see" the TMCC signal bleeding over.

One easy thing you could try is to remove or disconnect the TMCC antenna in the loco. I do not have any Atlas, but with most Lionel, a small wire nut is used to secure the antenna wire into the main wiring harness. Worst case would be to unsolder the wire from the antenna (usually a brass plate) and add a short wire so you could use a wire nut.

TMCC signals are low enough that disconnecting the antenna is sufficient to isolate the reception. The down side to this approach is you have to remove the loco shell to disconnect or reconnect. You could consider utilizing one of the existing switches on the bottom of the loco (e.g. the sounds or no sounds switch) and dedicate it to the antenna lead.

However - the longer the antenna feed wire the more likely it acts as an antenna by itself.

Good luck,
Roy

[4kitties]

Thanks Roy,

I hadn't thought of disconnecting the antenna wire. If the engine comes apart easily enough, I may try that.

Joel