433MHz interference

I have a recent episode (currently ongoing) of complete interference with my 433MHz spectrum.

Wondering if any can help me work out a way of finding the source. It’s extremely debilitating on all my systems, even the on/off plugs have a working distance of 1 foot or so.

My CurrentCost monitor is out, and Telldus works badly. Nexa plugs work from 1 foot and Emonhub on the pi works with a nearby sensor occasionally.

I live in a flat, and wonder if anyone has used a technical solution?


FInd the offending device and employ a large hammer…

Seriously, whatever is blasting the airwaves is probably not following the ISM rules (e.g. 1% occupancy) and if it is blocking like that, it is far too “loud”. So when you find the device (unlikely to be battery powered, so forget doorbells and car remotes) if turning off is impractical, at least turning down may be. Cut off/coil up its antenna if there is no user accessible adjustment.

Or approach the authority in your country that regulates the radio spectrum. Your IP address says you are in the UK, so you could try Ofcom.

Or consider moving to 868 MHz?

Turns out it was one of mine. It was a battery powered sensor that must have messed up.

Jeez, that was a right PITA.


Exactly. Strange thing is I did nothing to it, so not sure what made its behaviour change. Arduino based sensor. Am wondering if wires shorted or something.

It could even have been a naughty cosmic ray flipped a bit somewhere. Maybe it’s time to look at the watchdog timer and trip it if it transmits for too long?
(This is done with the voice communications in aircraft - hold the transmit button down and it raises an alarm eventually.)