I had coupler (bridge) installed and started to get erratic performance and an had an amplified on installed which did solve my problem.

My understanding of how it works is that a X10 xmitter sends the binary code twice over the power line and the amplifier sees the first signal and puts its own signal with higher voltage on top of the second signal.

Too bad the whole world can't standardize on things like voltage and frequency -- that reminds me, when I was a kid (a long time ago) we had a summer cottage in the mountains where the current was 110V 50Hz - everything worked okay except the electric clocks.

Good luck, Jim.