Re: Need some antenna advice (for my CM15A, of course)

[nobody@xxxxxxxxxxxx (Dave Houston)]

"Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> wrote:

>"Dave Houston" <ydobon@xxxxxxxxxxx> wrote in message
>
>> >>Anyway, lots of folks have put on better antennas and elevated the
>> >>unit (to the attic) and run long serial cable to the PC.
>> >
>> > I'll bet that moving the unit to a central location and using a long
>serial
>> > cable is probably the best *bang* for the buck.
>>
>> You'd lose your ante.
>
>I lost her in 1981!  :-)
>
>Well, I'd certainly have to defer to your deep knowledge in this area, but
>IIRC, the OP's not the only poster that has tried antenna modifications that
>failed.  I have some dead TM751s that were sacrificed to the antenna gods in
>the same pursuit. <sigh>  I wish I had tried relocating them centrally
>before I hacked them up since fine-tuning antenna and unit placement seemed
>to solve most of the problems I was having.  Ironically, it was your
>messages about reducing endless dims that led me to the solution to my RF
>range problem.
>
>http://forums.accessx10.com/showthread.php?%20%20s=&threadid=88
>
>Has an interesting (although limited) poll on the success of antenna mods.
>
>There are also lots of messages and photos that are of interest.  Here's
>someone else, who found, as I did, that high and horizontal were the two
>most important things to consider:
>
>"While digging deep into some other homeautomation boards, I found One more
>tip for everyone to try! I can't remember where I read it but one person
>setup their module (think It was a TM751,someone else used a cm15a) as high
>in the house as they could and had the antena horizontal This improved
>everyones reception that posted. One poster stated they could recieve
>signals from a palm pad anywhere on their 3/4 acre lot. So why not try it
>whith the cm15a set it horizonal with the antena pointed away from the unit
>also in a horizonal postion and as high as it can be mounted in the house."
>
>In terms of simplicity, lowest cost and easiest reversability, trying to
>locate the transceiver in the best place possible still seems a good, safe
>bet for the average X-10 enthusiast.  When I mounted mine high and
>horizontal, I could finally activate the porch lights from the driveway,
>something the little keychain remote could never do before.

Modifying the antenna on a TM751 or RR501 is not something I recommend. It
can have serious consequences, like DEATH from electrocution. You must
galvanically isolate any external antenna used with these modules as their
electronic "ground" is the hot side of the 120V mains. The CM15A electronics
are isolated from line voltage so it's safe to replace its antenna.

The thread you cited at AccessX10 is too muddled to make much sense of. The
MR26A antenna that one poster cited was based on my original antenna design
for the BX24-AHT. I've since found the eggbeater to be a better design.

The CM15A antenna is fixed length and cannot rotate as freely as those on
the TM751 or RR501. To have it horizontal, it would have to point out from
the unit and wall.

Most X-10 receivers have 25-35 foot range. My CM15A range is much greater
than it was with the OEM antenna.

I don't think much of X-10's software (or firmware) for the CM15A but the
hardware is excellent. IMO, it's worth a (small) bit of effort to make use
of it.