What's an acceptable noise level on that thing? My home indicates a level of 01 most of the time. Just for grins, I plugged a Chinese cell phone charger in next to it and got a level of 19-20 under no load, and somewhere near 40 under a load.
On another note, my Sears controller has an output signal of 5 to 7.2 when next to the XTBM, (which I assume is VERY good) while my CM15A give a reading of .17 across the house.
.01 for noise is very good. Here I read .01 to .02 most of the time. At .05 a nearby appliance module can begin missing commands. However, it really depends on the character of the noise. .05 (50mVpp) sitting right at 120KHz would be worse that 20 (200mVpp) far enough outside the X10 band to be pretty much rejected by the module filter. The XTBM does have peak sensitivity at 120KHz, so noise at that frequency will produce the highest reading.
I would suggest that any time the noise reads over .05, it is worth spending some time to identify the cause and isolate it with an appropriate filter.
I have found that X10 devices work reliably down to 100mVpp (.10 on the display). Below that things become marginal. FYI, my Maxi Controllers (OLD boxy Sears unit and a newer Leviton unit) also read around 7Vpp when sampled directly at the same power strip.
90 minutes is a very good assembly time.
Thank you all for the feedback.
Jeff