X-10 Signal Strength

Below is a list of nominal baseline measurements for a variety of X-10 transmitters measured at the transmitter. Readings were made with a pre-ELK version of the ESM1 and with a 'scope through an ACT Scope-Test2. Volages measured using the Scope-Test2 are about equal to the voltages measured using a 0.1µF capacitor and 100 ohm resistor; the Scope-Test2 does not appear to have any gain.

     Transmitter   Volts 
        CM11A      5Vpp¹
        CM15A      6Vpp
        30001      5Vpp      Stanley HomeLink Transceiver
        HCPRF      6Vpp      Leviton All Housecode Transceiver
        RR501      10Vpp
        TM751      10Vpp
  PL513/PSC04  	   10Vpp
  TW523/PSC05  	   10Vpp
        CP290      10Vpp
        MT522      10Vpp
        IR543      10Vpp
    PowerLinc      10Vpp

Additional data can be found in a couple of usenet threads:
     Thread 1     Thread 2
Note that all of the X-10 measurement devices currently available max out at 5Vpp or less so they give an incomplete (and inaccurate) picture.

¹ The CM11A output tends to start at about 5Vpp but taper off to 3-3.5Vpp over the 1ms burst. Changing R12 as recommended by John Galvin in Thread 2 results in a steady 5Vpp output.

Although most of it dates to 2001 or earlier, there is a wealth of data on using the powerline as a communications medium at Power Line Communication Bibliography.

The effects of other transmitters on signal strength can be seen by plugging a TW523 into the same powerstrip as a TM751. The TM751 output drops from 10Vpp to 8Vpp, a 20% decrease.

NOTE: The tests were carried out circa 2003. With the exception of a TM751 and RR501 made in 2011, I have not tested newer models so do not know if there are any changes.

The following screenshots were taken using an ACT Scope-Test2 adapter. All of the 120V, 60Hz signals use a x10 probe.

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