So we all know the CM15A range is pretty bad right out of the box. With the slimswitches I had a line of sight range of about 10ft and about 3ft if there was relatively thin wood board was in the way. That is pretty horrible!
There are many mods out there ranging from relatively complex and time consuming to some very simple mods that appear to work good as well. I had an old TM571 laying around so I took the screw out of it and pryed it apart (breaking it in the process) to get the antenna out. (Hey, it was all or nothing at this point for me since I was ready to scrap the whole X-10 system). Good news, the thing fits great into the CM15A...with a small mod. This mod falls into the category of voiding your warranty, but is quite simple and very effective.
What you will need:
TM571 Antenna
#10 Washer
Relatively thin wire
Soldering iron (and solder)
**for a cleaner install you will need a drill, tap, and small machine screw**
1. Get a #10 washer (hardware store or home depot) and slip it in between the tip of the TM571 antenna and the "base". You will need to take the screw from the antenna out and reasemble it after you put the washer on.
2. Now cut and strip the white wire on the CM15A and solder on a new wire (with a small stripped end) that can be attached to the new antenna. CURRENTLY, I stripped off the other end of the new wire and looped tied it in a knot around the antenna (but attached to the OUTSIDE of the box), leaving the shielded in to feed through the opening of the box. HOWEVER, it would be better attach this wire to the antenna on the inside. At a later date I will probably drill and tap a small hole in the antenna "base" and loop the wire around a small screw. But since I was just *hoping* this would work, I pushed forward and just looped the other end to the antenna on the outside of the box. This extra wire may not allow the box to close fully, but it will still be secure.
3. Insert the antenna, with the washer, into the slot. It will fit and look like it came from the factory this way (if you attached the new wire on the inside of the box). Otherwise, you will have a small wire connecting on the outside, which may not even be a big deal to you. Heck, I don't even know if you need to connect this wire up anyway?
Conclusion:
Night and day. I could not get the slimswitch to go through .5" plywood at 3' before. Now, I was able to go through 3 walls (including an A/C unit) at about 50' from the CM15A...with a slimswitch. Since I rent and this was far more than what I needed for my applications, I did not find out where it would not work. It worked at every location in my place and 30' outside of my apartment. Thats it, I went from being super frustrated to extremely happy!