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[paizano1]

I need help locating a post that was here about 3-4 days ago.  It had to do with range issues and it had a link to an old post about an antenna mod for the cm15a, it showed picts of a connector and some solid copper bar about 1/8 inch i assume.  Said about cutting it 9.5 inches and using 5 pieces and how to attach to a uhf connector i believe.  i can visually remember how to build antenna, my concern was how it was attached to the cm15a,, I thought i bookmarked it and didnt.  If anybody remembers this please repost or at least post link to older post that had the picts.

Thank you in advance.

[hawk1]

Just do a search for antenna mod.  I just looked this up yesterday.   

[dbemowsk]

Are you talking about this antenna?  I actually built this one and it works great.  The only things I did differently from the instructions here is:

• I didn't use brass rods.  I used some pieces of 14 gauge copper electrical wire.
• I didn't use the crimp on lugs.  I just cut the wire a little longer than needed and bent the ends into rings with needle-nose pliers and then cut it to length afterward measuring from the bent ring to the tip for the 9.5 inches.
• Lastly, I didn't use the screws and nuts.  I actually used my tap and die set and tapped threads into the holes and found some appropriate screws in my junk box.  I just did this because I didn't feel like running to the store and spending a buck on the screws and nuts (I know, I'm cheap).  Why buy things when you have tools and other parts that will work just as well.

You should do an F-connector mod to your CM15A.  An F-connector is a standard cable TV connector.  Here is a link to a great set of pictures for doing the mod..  Hope this helps.

Dan Bemowski

[eagle]

There are a few threads addressing the topic you are referring to.

Such topics are under the User Modified Devices subforum under General Home Automation.

http://forums.x10.com/index.php?board=122.0

r,
eagle

[paizano1]

thanks for the location of the article, i just have a question. After looking at the pictures and making one of the antennas with a cm15a F-mod, All places that i look for pictures of ground plane antennas seem to have the mounting of the antenna in the opposite direction, than what is shown in the pictures.  Even the post about the dual antenna mod where the antennas are located in the attic, ( great pics and seems like time well spent on that mod ). This particular attic mod also shows the antenna pointing with the single pole facing down. Am i missing something or is the antenna in fact supposed to be mounted this way. 

Antenna calculation and position are far beyond my normal thinking, this is why I have this question.

I was thinking since we assume the signal from the remotes is coming from inside the house and the location of antenna is in attic it should face the source.  If correct and i install one in attic and one in basement should the point towards each other or does it not matter.

Thanks for the help

[Brian H]

http://www.cocoontech.com/portal/articles/tutorials/home-automation/10-how-to-improve-your-x-10-rf-reception

In this construction How To the ground plane wires are bent down and the antenna is physically mounted upside down from the ceiling.

[eagle]

All places that i look for pictures of ground plane antennas seem to have the mounting of the antenna in the opposite direction, than what is shown in the pictures.  Even the post about the dual antenna mod where the antennas are located in the attic, ( great pics and seems like time well spent on that mod ). This particular attic mod also shows the antenna pointing with the single pole facing down. Am i missing something or is the antenna in fact supposed to be mounted this way. 

I was thinking since we assume the signal from the remotes is coming from inside the house and the location of antenna is in attic it should face the source.  If correct and i install one in attic and one in basement should the point towards each other or does it not matter.

I plan to build this antenna once I free up some time.  At any rate, Rat Shack has a similar antenna for under $30.  The reviews show the antenna installed with the single radial pointing up and the 4 radials pointed down.  Reviews on that antenna with the single radial up orientation yield strong reception of signals from miles away.

So, I'd probably go with the single radial up orientation first. 

r,
eagle

[dave w]

This particular attic mod also shows the antenna pointing with the single pole facing down. Am i missing something or is the antenna in fact supposed to be mounted this way. 

There is normally a small "dead zone" directly underneath the ground plane (the four antenna elements connected to the base of the UHF chassis connector) which explains the reason for mounting the antenna high with the 1/4 wave active element pointing down. In reality it probably does not matter.