I'm waiting for my next TMCC engine which should arrive this week. Of my other ones, most have signal problems. I have the 2r switcher, an 3r Allegheny, a 3r SD80MAC (not tested), and the 3r trackmobile. They sound great with just an AC transformer.
The base I tested was plugged into a cheap power strip. I thought it had a decent ground. It was hooked up temporarily to my 2 rail layout. I had not tried Carl's fix for both rail signal yet.
I'm hoping I just missed something simple. When I get my hands on another base, I will run a dedicated circuit with a ground from my electrical panel. I'd better start by eliminating the ground issue? I'll modify the antennas if I can figure out they need it. I've heard copper tape under the shell??