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🖥️ActiveHome Pro => ActiveHome Pro General => Help & Troubleshooting => Topic started by: solareclipse on October 06, 2015, 08:44:36 PM

Title: CM15A RF reception range keeps changing
Post by: solareclipse on October 06, 2015, 08:44:36 PM
Dusting off the old forum account, here... 

I've been using my CM15A & AHP for years now.  Recently I seem to be having issues with my RF range changing and I suspect a dying component in the CM15A, but maybe those more knowledgeable can lend their opinion.

My CM15A is in the outlet it's always been in, but sometimes it seems to struggle to pick up any signal, regardless of the transmitter.  I have a slimline switch 5 feet away, it won't work.  A PalmPad remote might work from the same distance, but not from 10' away.  Then the next day...  all my remotes will work fine from their usual locations.  The AHP activity log will show me when the RF signal is reaching it and when it's not, so it's not a powerline signal transmission issue, it's definitely on the RF side.

I unscrewed the CM15A just to see if there was a loose antenna wire or anything like that, but nothing is obvious, leading me to my suspicion of a dying device.  Considering the going rate for CM15As on eBay, I hesitate to jump on buying a replacement so I thought I'd post here first.

Any thoughts?
Title: Re: CM15A RF reception range keeps changing
Post by: dhouston on October 07, 2015, 05:24:33 AM
The RF receiver is a daughterboard which can be replaced if you can solder. You will also need to tune the replacement from 315MHz to 310MHz. See...
http://forums.x10.com/index.php?topic=21000.0 (http://forums.x10.com/index.php?topic=21000.0)
http://davehouston.org/ImproveCM15A.htm (http://davehouston.org/ImproveCM15A.htm)
http://davehouston.org/tuning.htm (http://davehouston.org/tuning.htm)
http://davehouston.org/eggbeater.pdf (http://davehouston.org/eggbeater.pdf)
Title: Re: CM15A RF reception range keeps changing
Post by: solareclipse on October 07, 2015, 09:05:47 AM
Thanks, Dave.  I actually landed on your page and read through some of that before I found that these forums were still active.  My soldering skills are pretty basic, but if I get annoyed enough I might give it a try. 

I was encouraged, then discouraged by what I've read about new product development for X10.  I was starting to think of trying to find a different brain to replace the CM15A that would still work with all my installed switches/remotes and provide similar functionality to AHP.  Got excited when I saw the new wifi unit & Android app being tested, then saw that there was no RF capability.  So sad...
Title: Re: CM15A RF reception range keeps changing
Post by: dave w on October 10, 2015, 11:06:49 AM
The irregular sensitivity sounds a little like outside interference. Have you explored that?
Title: Re: CM15A RF reception range keeps changing
Post by: Tuicemen on October 11, 2015, 08:29:47 AM
There are so many things that can affect RF reception.
Many can be over come just by  moving the Cm15.
The fact that it keeps changing rules out several possibilities.
I have to agree with dave w.

When the RF is reduced look at what else is on that may be using RF verses when the range is OK.
Also try placing the CM15 Higher in the house since RF works best with a clear sight transmission placing it higher may get it out of the line of sight of the offending culprit.
Another option would be the new SR751 RF repeater (http://www.x10.com/sr751.html) Although I had good results it tests that would be my last resort before replacing the CM15.
Authinx is slowly upgrading and improving their X10 Pro line  the RF side and PLC side eventually I see a new improved CM15 or maybe the WI-Fi unit will end up being its replacement.
 >!
Title: Re: CM15A RF reception range keeps changing
Post by: Brian H on October 11, 2015, 09:35:26 AM
Sometimes it can be an unexpected device.

I have some Lighting Science Group DFN A19 W27 V1 120V LED Bulbs. I had to remove from my home.
All the FM radios in the house got serious interference with those bulbs running and worse reception with an Off the Air TV station converter.
As a test I have a low cost RF spectrum analyzer. I see the noise floor increase on the X10 310MHz frequency when they are ON and a large set of spikes on the Insteon 915MHz frequency.
Title: Re: CM15A RF reception range keeps changing
Post by: solareclipse on October 13, 2015, 04:48:28 PM
Thanks, guys.  Lately it's been almost entirely not receiving RF signals, unless they're from a PalmPad that I wave around like a magic wand.  I've certainly considered the RF interference issue but didn't really have a good way to test it.  I do have more (Cree) LED bulbs in use than in the past.  Didn't realize they might be giving off RF interference, but they're not always on.  I have moved the CM15 around - it works best in an upstairs hallway outlet, but it's still suffering there. 

What's a cheap RF spectrum analyzer run?
Title: Re: CM15A RF reception range keeps changing
Post by: Noam on October 14, 2015, 01:12:30 PM
Have you tried a passive antenna mod on the CM15A?
I did it years ago, and noticed a difference immediately.

Take an 18-inch length of wire (make it as straight as you can) - it can be insulated or bare.
Attach it (non-electrically) alongside the CM15A's antenna. I originally used two strips of masking tape, but those were replaced by a sleeve of heat-shrink tubing purely for looks. Line up the wire with the bottom of the CM15A's antenna. That's all there is to it.

In simple terms, the wire helps "catch" the RF signals, and reflect them to the CM15A's antenna.
Title: Re: CM15A RF reception range keeps changing
Post by: solareclipse on October 14, 2015, 02:16:56 PM
Have you tried a passive antenna mod on the CM15A?
I did it years ago, and noticed a difference immediately.

Take an 18-inch length of wire (make it as straight as you can) - it can be insulated or bare.
Attach it (non-electrically) alongside the CM15A's antenna. I originally used two strips of masking tape, but those were replaced by a sleeve of heat-shrink tubing purely for looks. Line up the wire with the bottom of the CM15A's antenna. That's all there is to it.

In simple terms, the wire helps "catch" the RF signals, and reflect them to the CM15A's antenna.

Actually, yes.  I've had the wire hanger antenna extension mod since I've had the CM15A.
Title: Re: CM15A RF reception range keeps changing
Post by: Brian H on October 14, 2015, 03:19:58 PM
My RF Explorer WS1B1G that does 240-960MHz was $129.00
In hind site I may have gotten a different model. As the add on board for 15-2700Mhz seems to be MIA now.
Title: Re: CM15A RF reception range keeps changing
Post by: solareclipse on October 16, 2015, 01:47:58 PM
Another option would be the new SR751 RF repeater (http://www.x10.com/sr751.html) Although I had good results it tests that would be my last resort before replacing the CM15.
Authinx is slowly upgrading and improving their X10 Pro line  the RF side and PLC side eventually I see a new improved CM15 or maybe the WI-Fi unit will end up being its replacement.
 >!

Was there an old SR751 as well?  Just curious if the ones floating around on ebay are an old version or a new Authinx module.  Other than a plugin signal bridge I never got into the troubleshooting/range extender products.
Title: Re: CM15A RF reception range keeps changing
Post by: Brian H on October 16, 2015, 04:06:21 PM
There was an old model SR731.
It did not work very well.
From what I have seen in reviews. The SR751 is a much improved device.
Title: Re: CM15A RF reception range keeps changing
Post by: Tuicemen on October 16, 2015, 04:25:01 PM
Another option would be the new SR751 RF repeater (http://www.x10.com/sr751.html) Although I had good results it tests that would be my last resort before replacing the CM15.
Authinx is slowly upgrading and improving their X10 Pro line  the RF side and PLC side eventually I see a new improved CM15 or maybe the WI-Fi unit will end up being its replacement.
 >!

Was there an old SR751 as well?  Just curious if the ones floating around on ebay are an old version or a new Authinx module.  Other than a plugin signal bridge I never got into the troubleshooting/range extender products.
As Brian stated the old version was the SR731, however before purchasing from ebay be sure to contact the seller to be sure they aren't trying to pass off the old version for the new as there is no comparison.
 >!
Title: Re: CM15A RF reception range keeps changing
Post by: solareclipse on October 16, 2015, 05:17:25 PM
Thanks guys.  Same seller is selling on Amazon, so I'm going to give it a shot.  I'll let you all know how it works out.  >!
Title: Re: CM15A RF reception range keeps changing
Post by: solareclipse on October 20, 2015, 07:53:06 PM
Got the SR751 today, plugged it in, and it seems to be working pretty well.  Most of my slimline switches are now triggering again.  Still doesn't lead me to the root of the issue with the CM15A, but the SR751 must be sending a powerful enough RF signal to overcome the interference or antenna issue or whatever it is.

Now I'm debating adding a PLC01 to the mix and seeing if that fixes my few powerline signal issues.
Title: Re: CM15A RF reception range keeps changing
Post by: pomonabill22 on December 18, 2015, 03:21:18 PM
I have had a cm15a for several years and did the antenna modification and got amazing range.
Then, a couple of months ago, we had some very close lightening strikes, and my range went south.
I have also had solar installed and the panels are on the roof close to the antenna for my cm15a.

So I though the lightening strike might have wiped out the receiver in the cm15a, and/or the solar panels were affecting the reception.
I spent several days moving the antenna in the attic, and didn't help at all.

Then I scoped the receiver's output, both the analog and the digital, and saw the digital signal wasn't very "clean".
The power supplies looked good at first glance, so I didn't suspect the receiver.
A note, I did change the receiver from the original.

Still no luck BUT here is what it was!!!

I looked again at the power supply and noticed the 5 volts had about 350mV of 35Khz noise on it, and that was affecting the AGC of the receiver!!!!

I changed the power supply caps (C2, C11, C12) because C12 esr was WIDE OPEN!!!, C11 was VERY high, and C2 was also very high, meaning they were not capacitors anymore.

I also added a 470uF directly on the IC's power pins, just for fun and added 0.1uF caps in alot of places.

RESULT was EXCELLENT range... seemingly better than ever too!  So the caps, being cheap low temp. caps, close to hot components like power resistor and voltage regulator, cooked and opened up.  Normal poor design.

So if your RF sensitivity seems to be failing, or has failed, you might want to look at the electrolytic caps.  Their value isn't critical, except their voltage (higher is better, IF they fit).

This is a similar problem with plug in modules failing.
Title: Re: CM15A RF reception range keeps changing
Post by: Brian H on December 18, 2015, 04:08:08 PM
Thanks for the information.
Others have added four .1uF caps to the CM15A and improved things tremendously.
On IC's U1 & U3. Power Supply caps C11 and C12.

Found the schematic. Showing the added four capacitors.
http://web.archive.org/web/20150322033425/http://davehouston.org/CM15A.pdf

I have seen reports that X10WTI changed the PCB to accommodate easier to get surface mounted parts and I believe the RF circuits on the main PCB. So the caps maybe on different parts IDs now or even already there.
Title: Re: CM15A RF reception range keeps changing
Post by: solareclipse on December 18, 2015, 04:16:03 PM
I need to improve my soldering and electronics skills.  Or just hope that Authinx releases a newer, better product.   -:)
Title: Re: CM15A RF reception range keeps changing
Post by: dhouston on December 19, 2015, 09:02:01 AM
I have seen reports that X10WTI changed the PCB to accommodate easier to get surface mounted parts and I believe the RF circuits on the main PCB. So the caps maybe on different parts IDs now or even already there.
I don't think they added the caps to the 2013 redesign.
Title: Re: CM15A RF reception range keeps changing
Post by: solareclipse on April 13, 2016, 07:44:15 PM
Update: My CM15A had become so unreliable (and annoying) that I finally broke down and bought a used CM15A off eBay.  It works better than my old one ever did!  I can dim, it's receiving RF signals pretty reliably, still some problem rooms but those have always been the case.

Now I can experiment with repositioning the SR751 and PLC01 I bought to try and fix the problems and see if I can make an even stronger system.
Title: Re: CM15A RF reception range keeps changing
Post by: Brian H on April 14, 2016, 06:09:50 AM
Thanks for the update.
Title: Re: CM15A RF reception range keeps changing
Post by: dave w on April 14, 2016, 12:32:42 PM
I don't think they added the caps to the 2013 redesign.
I wonder if a SMD version would be more stable? (especially if the grounding around the chip was improved).