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[jrsutton]

I have been reading the POSTS about the poor receive range of the CM15A.  I had this problem, but it seems to me the solutions were overkill.  Here is what I put together for my CM15A:

I took a stiff plastic tube from a spray bottle (I used the tube from a Clean Shower bottle - it fits just right- about 9 1/2" long - about 0.16" Dia).  Cut off the angled end - drilled a small hole about 1/2" from one end and another about 1/4" from the other end.  I then took a 20 inch length of  26 GA. enameled copper wire and threaded one end through the hole that's 1/2" from the end and out the end of the tube - leaving 2" of wire hanging out the end.  I then wound the 18" onto the tube spacing it to end at the other hole.  I pushed a small piece of wire through the second hole to secure the wire.  I removed the base from the original antenna (small plastic elbow) and pushed it onto the new plastic tube with the wire threaded through the elbow.  The original elbow was filled with hot glue (this was very difficult to remove without destroying it).  I installed the new antenna and soldered it in place of the old one (I coiled some of the wire to make it more flexible).  The new antenna works much better than the original.

[Brian H]

  Nice mod and photos. Thank you for sharing with all as it maybe a big help to others.

[x10challanged]

  Great pics, any idea about how much improvement this made to the reception? i.e. increased 2' or 50'

[jrsutton]

I'm not sure how much increase there is in range.  I have the CM15A in one end of the house and could not get my KR19A to work in the other end of the house.  With the mod the KR19A works in the whole house - maybe 30 - 40 ft through walls.

[Dan Lawrence]

Excellent mod and writeup.

Since people from X10 do read the posts here, it would be wise to make a production change to the CM15A and use the longer antenna as it does solve range problems.

[jrsutton]

I would hope that X10 would do some design work and come up with a loaded monopole that is tuned to the correct frequency.

This antenna is basically a whip or monopole.  It should be i/4 wavelength long or some ware around 18 inches.  My goal was to make an antenna somewhere around the correct equivalent length, by using a loaded whip design (I didn't spend any time making it an exact design), I'm sure an engineer at X10 could do a better job)

[Alan V]

I would hope that X10 would do some design work and come up with a loaded monopole that is tuned to the correct frequency.

This antenna is basically a whip or monopole.  It should be i/4 wavelength long or some ware around 18 inches.  My goal was to make an antenna somewhere around the correct equivalent length, by using a loaded whip design (I didn't spend any time making it an exact design), I'm sure an engineer at X10 could do a better job)

I think that the poor antenna design is just part of the problem with the CM15A.  The receiver sensitivity also seems to be especially poor.  I have tried several antenna mods and have seen only a moderate increase in range.

Like several others in this forum, I use a V572A from WGL Designs as my transceiver, and bybass the receiver in the CM15A.  The resulting performance is excellent.  I've never looked back.

[JimC]

Like several others in this forum, I use a V572A from WGL Designs as my transceiver, and bybass the receiver in the CM15A.  The resulting performance is excellent.  I've never looked back.

I must agree with Alan, the V572A has made a world of difference in the performance of my wireless devices. There is not an area in my home or yard that is out of range of any of the wireless devices (motion sensors, Keychain remotes, stick up switch) They all just work even at the farthest extent of my 1/2 acre yard.

[steven r]

...The receiver sensitivity also seems to be especially poor...

Less of an issue to most is the transmitter inside. It could benefit from a boast also.

[JimC]

Less of an issue to most is the transmitter inside. It could benefit from a boast also.

How true. If the transmitter were improved my remotely located Ninjas might even work.

[Dan Lawrence]

Interesting, but I noticed that the V572A is a serial device.  The possible serial port problem that killed the CM11A for XP users with certain motherboards might not allow use of the V572A either. 

Has anyone using the V572A ever had the "vanishing/reappearing" problem the CM11A had?

[JimC]

Dan,

The V572A only need be connected to a computer for initial setup and then only to set what house codes will be repeated onto the power lines. I am running Windows XP and had no problems.

I use numerous peaces of serial hardware with XP and have no problems. The problem you speak of seems to be peculiar to the CM11A.

[Alan V]

Less of an issue to most is the transmitter inside. It could benefit from a boast also.

How true. If the transmitter were improved my remotely located Ninjas might even work.

Here too I think that the problem is primarily in the design of the receiver in the Ninja.  Transmitters are relatively easy to design.  But designing a receiver with good sensitivity and specitivity is much more difficult to accomplish.  Unfortunately, X10 just doesn't seem to use very good receivers in their products.

[Dan Lawrence]

Dan,

The V572A only need be connected to a computer for initial setup and then only to set what house codes will be repeated onto the power lines. I am running Windows XP and had no problems.

I use numerous peaces of serial hardware with XP and have no problems. The problem you speak of seems to be peculiar to the CM15A.

The problem was with the CM11A (not the CM15A) and was motherboard specific.  I had an old custom-built PC that ran Windows98 fine.  When I updated to XP, the CM11A began to disappear and reappear due to COM port problems, so I upgraded to AHP/CM15A.   That's what I was posting about.

[JimC]

The problem was with the CM11A (not the CM15A)

Oops!, Typo. I meant CM11A. I will correct that in my previous post.