Re: X-10 RF home automation being overwhelmed by M2 OFF, C2 OFF and Gxx DIM signals

[dlh <dlh@xxxxxxxxxxxxxxx>]

This gets too unwieldy - trying to post inline so I'll try to cover
everything without any quoted text.

It's unlikely but possible that it's coming in via the powerlines.
Your reading with Jeff Volp's device is _probably_ reporting the
translated PLC command although I cannot think of a reason for the
lower frequency. The transceivers tend to have very wide RF bandwidth
and PLC receivers do as well, usually reacting to signals in the
75-200kHz range. There was something a few years back, which I dubbed
the "Endless Dim Syndrome" where the valid 120kHz was being radiated
by the in-wall wiring and inductively coupling to TM751s (mostly) via
their antenna. It was fairly easy to induce by aligning the antenna
with the wiring. However, only Dims & Brights were reported by the
victims. The TM751 was apparently cheating, assuming that any further
RF meant the remote was still sending and the poor design of the RF
receiver allowed it to respond to the lower frequency. Recent TM751s
use the same high-quality RF receiver used by the CM15A but I have no
idea when that change occured.

You can steal the RF receiver daughterboard from a TM751 but I'm not
sure I recall the connections. The RF receiver daughterboard in the
CM15A is much better but I'd hate to see you cannibalize a CM15A. The
315MHz receiver is the one, should you go that way - turn the tuning
slug 1/8T CCW and you'll be close enough.

You should be able to find a freeware/shareware oscilloscope program
that uses the soundcard. It's easier than the methods in my article
which was written long ago.

The decoded bits don't tell me what I want to know. It may be that the
codes are actually longer and the X-10 receivers are just grabbing the
first 32 bits - I never thought to test whether that was possible.
But, if the codes are longer, we can possibly rule out an X-10 source
(some X-10 security codes are longer). Of course, X-10's limited range
probably rules out a nearby source. X-10 uses NEC's IR code which
dates back 40+ years and has been copied with slight modifications by
many others. I haven't encountered any others using it for RF but I've
been occupied elsewhere (several surgeries and other hospitalizations)
over the past 18 months or so. We might learn something from the raw
codes. And, if it is a high-power source, it may just be overwhelming
the receivers as those military tests a few years back did to the
garage doors which normally only respond to rolling codes (different
with each transmission).

Pepco is unlikely to be helpful unless you reach the right person.
Duke's regional engineer came to investigate an issue I had a couple
of years ago and he was quite sharp but the ones I talked to before he
came by were clueless.

IIRC, some folks on the West Coast were having some X-10 issues with a
specific smart electric meter. I don't recall details. I think there
was a discussion (with Jeff Volp's participation) on the X-10
Community Forums. Duke Energy installed Excellon meters here a couple
of years back. I've seen no X-10 issues but have had two (different
brand) inexpensive 700W microwaves lose their minds - beeping randomly
and flashing or clearing the displays. I've suspected the new smart
meters might have been outputting something that got by any filters
the microwaves might have had. I now have a 1000W Haier Grill/
Convection/Microwave combo that seems immune (so far).