There's a lot of likely sources for this. Two that seem to be the most likely are IED jammers because this is the Washington DC and is clearly a "rich target." The second is something coming in on the powerlines that the power company uses to read, control or in some other way interact with meters and remote controls that allow them to shut down your central AC during a brownout (you get a rebate for letting them install the box).
The signal disappeared completely after 9/11, leading me to believe it's an anti-IED transmission.
The wierdest thing about this is that the RF signal has some primitive error checking that shouldn't allow plain old interference to be interpreted as valid commands. Usually, anything that generates an unwanted X-10 command is a piece of X-10 equipment gone mad. They make a plug in controlled called the CM11A that would "speak in tongues" and flood the line with spurious (but correctly formed) X-10 commands if you happened to leave the serial cable used to communicate with the PC connected to the CM11A but not the PC.
It's a headscratcher for sure but that's part of the "charm" of X-10. It's been responsible for my learning all about AC power, sine waves, wiring up
240VAC gear to the circuit box, etc. But when it works, it's just like magic, so it's worth the trouble, at least to me. Stock X-10 gear doesn't work well anymore because of all the switching power supplies and fluorescent lights that can stomp on the relatively weak signal (about 5V). I use a device made by a guy named Jeff Volp that amplifies that weak signal into one over 25V. That can punch through way more interference and makes all the difference in making X10 a reliable protocol again, the way it was when first introduced into a switching-power supply world over 20 years ago.
I'm pleased with the oven but not happy with Haier America. I bought a new but slightly dented unit, saving about $50 including shipping over a pristine one from Amazon with free shipping but it's missing a user manual and a couple of plastic feet on its bottom. They have an email link on their web page but have ignored 3 emails. I'll try their 800 number next week. I've had a hectic couple of weeks from a reaction to a change in medication (and from frequent visits from the team of nurses and techs the VA's Home Based Primary Care program has assigned me) so haven't gotten around to it yet. If you buy one, you can make me a copy of the manual if I still need one. It's a lot more complicated than a plain old microwave and I haven't figured out all the secret handshakes yet.
Had you populated the BX24-AHT board you got, it reports RF signal strength so might have made a crude direction finder with the right antenna. You can get some highly directional yagi antennas that are printed circuits which would help even more.
Thanks for the suggestion but I buy filters by the dozen! This is/was very odd in that it kept broadcasting 3 different X-10 codes by RF only. No way to filter it out unless I build a Faraday cage around my house. The good news is that it stopped right after 9/11. Don't know where it came from, don't know where it went. All I know is that I am very, very happy it is gone. Nothing like something not working anymore to realize how much you depend on it.
A quick (for me!) followup, so please forgive the top post. Interference was off for a week after Labor day but is now back on again full force. Just stopped at 5AM. Distributed 6 TM751's located proximate to most important RF switch controls as their effective range bathed in interference is about 6 feet. No collisions with each other because except for a few spots, each TM751 is in a non-contiguous sphere. Does NOT work with the WGL transceiver active, too. Collision city.
Two kinds of X-10 interference in this case. One is plain old noise, the other is noise that the X-10 receivers believe is an actual X-10 transmission.
I haven't yet "run down" the noise because a) I am lazy and b) IMHO, it's not a solution if it depends on something or someone external to my house doing something.
All in all it's been an interesting study in how low power gear like X-10 RF acts when receiving "undesired" interference (is it ever desirable?"). Now I'm going to see if I can put those TM751's on lamp or appliance modules to switch between the WGL global network or the array of TM751's. There might be some very strong benefits to being able to disable RF control, room by room. X-10. Forever futzing. (-:
-- Bobby G.
If you could capture the raw RF signal using the techniques shown on my website it might help identify the source.
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Who supplies your electricity? Have they recently installed new meters that can be read remotely? I've seen a few reports of problems from some metering systems although nothing similar to what you are experiencing.
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