My problems have been solved!!
In searching for replacement phase couplers/amplifiers I found the Leviton HCA02-10E Coupler/Repeater. For those unfamiliar, it is a phase coupler that receives the X10 signals and immediately turns around and sends the signals back out on both phases. This device was around $70 and is a godsend. I used to have to schedule two or three "off" trips for some modules and with the repeater in the circuit everything is working better than ever! Money well spent! It does require hard wiring into an electrical panel but is very easy to install.
Ben,
I'm coming in a bit late here but, as you've already learned, a repeater can provide a world of help to X10 signals.
Unfortunately (yep there's always on of these), the HCA02 has problems with dim commands. Sending repeated dim commands to multiple devices can lockup the HCA02/CM15a. If you are using dim commands in macros, make sure they are separated by a couple of seconds delay.
BTW, I've had a HCA02 for a number of years now. My system won't operate without it.
How does one get and install one of these repeaters?
I used to run X10 about 27 years ago without concern about what circuit things were on. But now with a new set up I'm finding some units don't work. I used one of those transceiver units in a nearby outlet and picked up a few of the ones that didn't work before. I got a second interface and have the two working to control different locations. But it is a pain. I think it is at least partially a phasing thing.
Saber Dog,
Here's a link for various couplers and repeaters.
Link : Topic: [VOLUNTEERS] *Comprehensive* Filter, Passive Coupler & Signal Analyzer LINK List The simplest is the "SignalLinc" that plugs into an existing 220V dryer outlet. I prefer the wire in type (ACT, Leviton, X10Pro) that mount in a double wide box next to your load panel.
There are a number of repeaters that are missing from the above link. A notable "missing" entry would be the XTB-II and XTB-IIR designed by Jeff Volp. Jeff has a number of posts and helpfull procedures under the thread:
Link: Powerline Control Reliability