TMCC SC-2

They receive their signal from the track. They are intended to be mounted on the underside of the table underneath the track. They may be too far from the signal to be getting a clear signal. Try routing the TMCC signal wire from the base near all the SC2s and see if that helps 

I would say try the opposite of more track signal - try more earth ground, which is effectively the other half of the TMCC signal.

I looped an earth ground wire around my SC-2s, and they went from flaky to 100% reliable.

You can tap into the base’s earth ground from the COM wire going to your TPC.

I connected the outside rail, the wire that the base connects to, to COM on the units. Then I did run a ground wire (the airborne signal) over the units. The com connection made the biggest difference.

I have seven of the SC-2s mounted under the layout and below the track. None of these are powered from the wall warts, these are daisy chained from a Powerhouse. These all work as they should but at one location I need to hold the remote either higher or lower to get one switch to operate. I might need to run the ground plane wire around the SC-2s, something to try.

Ray 

The signal to the SC-2 comes from the base. It may be a wifi issue from the remote to the base that you noticed. But if the remote is properly talking to the base, then the SC-2 depends only on the signal from the base.

It’s not a ground plane. The late Dale M campaigned to get the word “plane” out of the dialog about the ground wire. It didn’t happen. It’s just too catchy to use the word plane in the description even though it totally has no basis in this application. And in fact, it seems to encourage folks to use aluminum or copper foil in areas that the upper track shields the lower track from the signal. It doesn’t hurt but is unnecessary. You only need a wire. It’s only a wire connected to the AC ground wiring in your house that transmits the signal into the air above the layout. The other “half” of the signal is supplied by the base connection to the outside rails of the track.

Hang a ground connected wire over your SC-2 if the signal is shielded from the signal in the air above the layout. And make a connection from the outside rail or base terminal to the COM terminal of the SC-2. It’s been the best solution for me. 

Thanks for all the suggestions.

I'll give them a try and report back what happens.