Not true, each SignaLinc is listening to each other and repeating signals it hears via both powerline and RF. Every INSTEON device is capable of repeating the signal, some only via powerline, some only RF (like battery operated motion sensors, not avaiable yet) or on both powerline & RF. The whole concept is to get the signal to its destination without failure. You had quoted that your ACT coupler does the same thing as the SignaLinc bridging the phases, yes it is a bridge, but can you do this.... Talk to your neighbors, plug a SignaLinc in each of their homes (making sure one can see the next by RF and so on, outside wall outlets work best for this test since the RF signals travel farther across open air.) Then put a switch in your house, and a lamp module 5 houses down..... guess what you won't have any problems controlling the lamp from your house. This is similar to the way Z-Wave works by broadcasting the signal across the RF (you can do the same above test with Z-Wave using Z-Wave modules). INSTEON is using both forms (powerline and RF) to transfer the signal to its destination module and back again to the controller to confirm that it has been received and executed. Unlike X-10, both Z-Wave and INSTEON become more reliable with each module you add. X-10 is just the opposite, add more modules (especially 2-ways) and your signal becomes weaker because they absorb some of the signal. Yes there are now some X-10 modules from SmartHome that include boosterlincs built into them, but its not every module available.markthomas said:Once you have these things sending RF throughout the house, then what? Nothing's listening to it.