Please login or register.

Login with username, password and session length
Pages: [1] 2

Author Topic: CM15A RF Range Improvement  (Read 7777 times)

rob meldrum

  • Newbie
  • Helpful Post Rating: 0
  • Posts: 5
CM15A RF Range Improvement
« on: September 20, 2005, 10:47:57 PM »

Hi all,  After 12 months of waiting for our
new house to be built, we're moving in next
month.  I am now re-testing all my X10
paraphernalia.  The CM15A RF range with the
keychain remote was 15 feet.  Ugh.  I did
the range mod, but used an inexpensive
dipole antenna from Radio Shack (the wire
in a clear sheath, in a "T" used for FM
reception in lots of stereos) and now I
have reliable RF reception from the
keychain remote in my entire 4000 sq ft
house, plus from the driveway.  Amazing.
Looking forward to setting up and testing
motion sensors, dimmers, etc.  Now that
this is fixed, the next big issue is making
sure the X10 signals are getting through.
Need to add a phase coupler and
X10 "filters."  Will keep you posted on
progress.
Rob
Logged

Brian H

  • Community Organizer
  • Hero Member
  • ***
  • Helpful Post Rating: 305
  • Posts: 13259
Re: CM15A RF Range Improvement
« Reply #1 on: September 21, 2005, 04:54:29 AM »

OH Yes the mod does make things work so much
better. We will stay tuned for future
updates and questions.
Logged

roger1818

  • Hero Member
  • *****
  • Helpful Post Rating: 28
  • Posts: 1072
  • Roger H.
Re: CM15A RF Range Improvement
« Reply #2 on: September 21, 2005, 01:55:49 PM »

Rob:  Did you change the length of the of
the dipole antenna?  Also, did you use a
matching transformer?  Does anyone know
what impedance the CM15A is expecting to
see?
Logged

Brian H

  • Community Organizer
  • Hero Member
  • ***
  • Helpful Post Rating: 305
  • Posts: 13259
Re: CM15A RF Range Improvement
« Reply #3 on: September 21, 2005, 07:59:03 PM »

Schematic for the receiver isn't much help
[says 240mm for lenght] as is the receiver
chip makers refference design show the
impedance. The WGL v572 that uses a simmilar
receiver module comes with RG6 cable that is
75 ohms but that isn't 100% on what X10s
uses. Thank goodness receivers are more
forgiving than transmitters. When I tested
my modified cm15a I used the WGL supplied
one. I have also seen a message on the
accessha.com forum where someone got better
distance just by uncoiling the extra antenna
wire inside the cm15a and putting a longer
hollow tube in place of the shorter one on
the side with the wire fully extended.
Logged

bob linca

  • Full Member
  • ***
  • Helpful Post Rating: 0
  • Posts: 61
Re: CM15A RF Range Improvement
« Reply #4 on: September 21, 2005, 10:49:08 PM »

Rob Meldrum,

What is the part number for the antenna that
you used, and how did you connect it to the
CM15A?

Thanks,

Bob
Logged

rob meldrum

  • Newbie
  • Helpful Post Rating: 0
  • Posts: 5
Re: CM15A RF Range Improvement
« Reply #5 on: September 22, 2005, 12:20:19 AM »

Glad someone is interested!  Radio Shack FM
dipole antenna:
http://www.radioshack.com/product.asp?
catalog%5Fname=CTLG&product%5Fid=42-2385
First I tried straightening out the
internal antenna, got *maybe* an extra
three feet of coverage, and this is in an
open area, no walls, range died at fifteen
feet with regular unit, maybe two-three
more feet with antenna extended.  The
antenna mod is described here in other
threads, but the link is:
http://www.accessha.com/howto_fconnector_pag
e1.html
I did *not* make a coax connection, as I am
a novice at messing with electronics.  I
soldered in a ground wire per the link, cut
the antenna wire, and soldered each to a
female spade connector.  I used a glue gun
to glue the two wires firmly to the box
where the old antenna connected.  I mounted
the dipole antenna on a wall, with
the "arms" of the antenna at right angles.
Plug the CM15A in to the dipole antenna
with the spade connectors, and suddenly the
weak keychain remote works everywhere in
the house.  PalmPad remote works great,
too.  I was very pleased at how easy this
mod was.  In about three weeks we'll be
moving in and I'll have more to report.
Feel free to ask if I can be of help!
Rob
Logged

rob meldrum

  • Newbie
  • Helpful Post Rating: 0
  • Posts: 5
Re: CM15A RF Range Improvement
« Reply #6 on: September 22, 2005, 12:27:11 AM »

Roger,
I did not change the antenna in any way.
I'm too electronically illiterate to know
about impedance or transformers.  I did try
using lengths of coat hangers first (some
random web site suggested that), but they
didn't help at all.  I'm about to order a
phase coupler to connect at the 220-volt
dryer.  I think I'll order an active
bridge, does that make sense to you?

Rob
Logged

roger1818

  • Hero Member
  • *****
  • Helpful Post Rating: 28
  • Posts: 1072
  • Roger H.
Re: CM15A RF Range Improvement
« Reply #7 on: September 22, 2005, 09:25:42 AM »

Rob:  Thanks for the info.  It makes me
wonder if that isn't a better approach than
using an F connector.  When the warrantee
expires on my unit in December, I will have
to do a similar mod.

With regards to the phase coupler, I highly
recommend getting one.  Check out a
tutorial I wrote at:
http://www.x10.webhop.org/Phase_Coupling.htm

One word of caution though, if you are
using a CM15A, I would stay away from the
Smarthome and Leviton (and probably X10 Pro
since the Leviton is made by X10) brands of
Coupler/Repeaters (their passive couplers
are fine).  People on here have reported
that when used with a CM15A a flood
of “Status Request” signals will start
being sent that prevent other commands from
being transmitted.  The ACT brand
coupler/repeaters apparently don’t have
this problem.

I suspect it is a bug in the CM15A and not
the coupler/repeater (in a separate thread
I theorized a cause of this problem), but
regardless of the exact cause it is best to
avoid these combinations.
Logged

sparky

  • Newbie
  • Helpful Post Rating: 0
  • Posts: 2
Re: CM15A RF Range Improvement
« Reply #8 on: September 23, 2005, 07:41:13 AM »

HI
having trouble with remotes
communicating.the seem to only some of the
time.added phase coupler.i like te idea of
the ant mod.how can i do this? thanks
Logged

sparky

  • Newbie
  • Helpful Post Rating: 0
  • Posts: 2
Re: CM15A RF Range Improvement
« Reply #9 on: September 23, 2005, 07:41:22 AM »

HI
having trouble with remotes
communicating.the seem to only some of the
time.added phase coupler.i like te idea of
the ant mod.how can i do this? thanks
Logged

JimC

  • Hero Member
  • *****
  • Helpful Post Rating: 41
  • Posts: 631
Re: CM15A RF Range Improvement
« Reply #10 on: September 23, 2005, 01:49:44 PM »

Sparky,

Go to the following web site and click on
projects. you will find the antenna mod
there.
http://www.accessha.com/index.html
Logged
_ _ ...  ..._ _

Brian H

  • Community Organizer
  • Hero Member
  • ***
  • Helpful Post Rating: 305
  • Posts: 13259
Re: CM15A RF Range Improvement
« Reply #11 on: September 23, 2005, 01:54:56 PM »

Only update for that mod is. If you have a
later unit. The extra antenna wire maybe
glued to the case in a loop and not balled
up in a mess like my early one was.
Logged

Brian H

  • Community Organizer
  • Hero Member
  • ***
  • Helpful Post Rating: 305
  • Posts: 13259
Re: CM15A RF Range Improvement
« Reply #12 on: September 23, 2005, 02:34:11 PM »

Correction. The transmitting antenna is
glued to the cover. In my later one the
extra length of the receiving one was glued
in a 'U' shape to the main board between the
receiving and transmitting daughter cards.
Logged

michael ferguson

  • Newbie
  • Helpful Post Rating: 0
  • Posts: 7
Re: CM15A RF Range Improvement
« Reply #13 on: October 02, 2005, 12:22:14 PM »

Roger said: The ACT brand  coupler/repeaters apparently
don’t have this problem.

I'm sorry to report that I have two new ACT CR234 units
here that both exhibit the signal storm within 1 hour of
plugging them in...

michael
Logged

john t.

  • Full Member
  • ***
  • Helpful Post Rating: 0
  • Posts: 27
Re: CM15A RF Range Improvement
« Reply #14 on: October 02, 2005, 10:57:52 PM »

I understand that the SmartHome USB
controller 1132UCP doesn't have the rf range
problem exhibited by the CM15A. Anyone know
if that is the case???

John
Logged
Pages: [1] 2
 

X10.com | About X10 | X10 Security Systems | Cameras| Package Deals
© Copyright 2014-2016 X10.com All rights reserved.