CM15A Two Ext Ants Mod

[Frank3d]

I started my X10 system as a camera only system with Vanguard Internet Control Center. With it came the CM19A USB to X10 RF control module. I modified it for an external antenna so I could get the camera RF control distance I required. I also designed a 2.4Ghz passive antenna system for the cameras video that works very well. Since then I have expanded my X10 camera only system for PLC to other X10 modules with AHP and all the cool plug-ins for it like iWatchMobile Pro that works excellent with my iPhone. My dilemma was the CM19A would only do RF X10 commands and not PLC so I added a TM751 RF to PLC repeater. Then I wanted to receive motion detection from a pair of PR511 motion Flood lights (PLC only) to trigger macros in AHP. Not so with my setup then because the TM751 is not bidirectional there for it would not detect PLC's and convert them to RF commands for the CM19A used with AHP, it only converts RF commands to PLC's (unidirectional). I had to dig out the CM15A that came with my AHP but was skeptical weather it would have the same range the CM19A had. I modified the CM15A with two BNC M external antenna connectors on two short lengths of RG58 coax cable, one for the Tx and another for the Rx daughter boards inside the CM15A. This allowed me to test the CM15A's output Tx compared to the CM19A's output. I was happy to find that the CM15A had 0dbm output compared to only -6dbm output from the CM19A. That means the CM15A has a 6dbm higher output than the CM19A but another plus with the CM15A is that it is crystal controlled and exactly on frequency (310Mhz) unlike the CM19A's frequency that has a habit of drifting with temperature. I am now successfully using the CM15A and able to test all that AHP has to offer. I included a picture of the CM15A ants Mod. Unfortunately you have to be good at soldering to attempt this mod and I don’t recommend it except for testing purposes because of FCC regulations.

[HA Dave]

A great post, picture, mod, and test result info Frank3d. A helpful and... thank-you from me.

[Brandt]

The w800's use RG6 I would recommend that over RG58 or RG59

[Frank3d]

The w800's use RG6 I would recommend that over RG58 or RG59

Brandt,
Why RG6 75ohm coax instead of RG58 50ohm coax? The 9" antenna lengths are for a 50ohm quarter wave antenna impedance. Besides RG6 is larger in diameter. RG58 is standard CB antenna cable and many types of connectors are available for it.

Edited: by Tuicemen to fix quote (readability)

[Brian H]

Helpful from me also.

The W800 and the V572 do use RG6 but they maybe using the 75 Ohm impedance in their equipment.

[Frank3d]

Helpful from me also.

The W800 and the V572 do use RG6 but they maybe using the 75 Ohm impedance in their equipment.

Brian, Thanks for the input. If I may interject that RG6 has a little lower loss than RG58 per meter (good) but varired type connectors ( other than F connectors for Sat & Cable TV ) are not easily available for RG6 here in the US.

Tuicemen, Thanks for correcting my post..........

[Brian H]

Yes that is most likely why WGL used F connectors.