CM15A signal output

[dbemowsk]

This is probably a question more suited for Jeff V or Dave H.  Is there a way to boost the PLC signal output on a CM15A?

[Knightrider]

Dan,

Plugging it into an XTB comes to mind.  

(I'm not qualified to answer about an internal modification -- I have yet to open one up)

[Brian H]

I don't see anything on the CM15A schematic where you could change someting to increase the signal on the power lines.
An external device like the XTB would be one way to go.

[Noam]

From what I understand, that's precisely the reason Jeff developed the XTB series of devices.

That said, using filters to reduce signal suckers and other noise-generators might accomplish the same goal (getting a stronger signal to your devices).

[JeffVolp]

Is there a way to boost the PLC signal output on a CM15A?

The CM15A is efficiently designed to do what it does.  While a mod to increase its output might be feasible, it would require massive changes, including replacing the tiny 120KHz transformers with custom designed units that could handle higher currents.

Jeff

[Brian H]

Not to mention the power suppply.
I doubt there is lots of reserve power in it.

[dhouston]

Is there a way to boost the PLC signal output on a CM15A?

Have it repeat the command via RF to a TM751. 

I measured the outputs of most X-10 PLC transmitters a few years back. Most of the pre-CM11A devices output about 10Vpp while the CM11A outputs 5Vpp (which fades quickly) and the CM15A outputs 6Vpp. Short of using an XTB, your best bet is to find and eliminate any signal attenuators (suckers) which is not always easy to do.

http://davehouston.org/x10-sig.htm

[dbemowsk]

Thanks for all the replies.  I am still thinking of getting an XTB-IIR (if they are still available), but funding is a bit short at the moment.  I just thought if there was a mod that could be done, I'd give it a shot since I have a spare CM15A.

[dave w]

Thanks for all the replies.  I am still thinking of getting an XTB-IIR (if they are still available), but funding is a bit short at the moment. 

Hold your nose and use a $20 XPCR until you can afford the XTBIIR. I'm sorta in the same boat (between jobs), but saving my pennys . Our ACT CR234 is a strong performer but "ain't nuttin like a XTBIIR".

[dbemowsk]

I have heard nuthin but AWESOME reviews on them and I want one in a bad way. 

[johnlaw45]

I wish they would update the software on the old units which worked a lot better than the CM15A so we could use them on Windows 7 and have the signals we used to get before they replaced them with these low output CM15A units. I for one miss being able to get X10 signals across my entire house like I used to.

[dhouston]

As I noted earlier in the thread, the lower output started with the CM11A (the CM15A is a little better than it). Europe limits PLC signals to 5Vpp and X-10 likes to use the same basic design (aside from line voltage and plugs) there as in N. America so that may be a factor. I'm unaware of any limit in the US although there are limits on unintended conducted emissions which accounts for the signal suckering capacitors across the mains that manufacturers have added to so many non-X10 devices. I have not done an extensive study of FCC rules on this point so there may be something I missed.

AFAIK, the FCC limits cover 150kHz-30MHz so X-10 (and Insteon) would seem to be exempt. However, there is an International standard, CISPR 22 which has been adopted in much of Europe, which applies from 9kHz-30MHz. I have no idea whether it applies to N. America. It may be that X-10 expected CISPR 22 limits to eventually apply in N. America - the 9kHz lower limit dates to 1993. When was the CM11A introduced?  

Also, units from other manufacturers introduced after X-10's patent expired (Stanley Homelink 30001, Leviton HCPRF,  Powerlinc) tend to have similar outputs to the later X-10 units which may be another indication that they expected regulatory tightening.

[Noam]

I wish they would update the software on the old units which worked a lot better than the CM15A so we could use them on Windows 7 and have the signals we used to get before they replaced them with these low output CM15A units. I for one miss being able to get X10 signals across my entire house like I used to.

To which "old units" are you referring?
If you mean the CM11A, AHP now supports that unit.
You can download the latest version of AHP here:
http://www.x10.com/support/support_soft1.htm

[dhouston]

Actually, the CM11A output was slightly lower than the CM15A. It also faded fairly quickly, dropping 20% in 1mS, so the CM15A is probably a better choice. However, there is a modification to the CM11A that will fix the fading. There's a link to John Galvin's mod at the URL referenced below.

I suspect the older units referred to are the PL513/TW523, TM751,  RR501,  CP290, etc. which output nearly twice what the latest devices output. See... .http://davehouston.org/x10-sig.htm