Helping build a toy train style layout, 14 x 9, Fastrack with 10 switches. Started out as strictly conventional, then Lionchief Plus crept in, now TMCC, who knows what is next.
Anyway, figured I would install all the Switch Commanders. First 6 went fine, next 4 were erratic if not completely dead. Mind you, the 4 problem switches are all within a 12 inch radius and are separated from each other by no more than one track section. Two of them are directly connected to a switch that gives no trouble!
To make a long story short, it was indeed a signal level problem, but I was thrown off the scent by the fact that TMCC locomotives had no trouble operating over the unresponsive switches. But, throwing an extension cord (lazy way to temporarily install a ground plane) along side the switches made them work perfectly.
Apparently, the close proximity of the "antenna" on the Switch Commander to the rails limits its performance.
I must admit that I was a bit surprised to discover this issue on small layout, I had figured that you need a bit bigger spread to get into this stuff.
