EM interference from Hive or smart meters?

Alec_t

Alec_t

Joined
18 Mar 2017
Messages
1,242
Reaction score
257
Location
Wales
Country
United Kingdom
I'm getting occasional ghost rings on my wireless doorbell, day or night, but I'm not sure what is triggering them. I have two different brands of bell, but both suffer from these ghost rings. The bell/bell-push use the 433MHz band (as do various garage door openers and other remotes, so one of those is the most likely culprit). I've fitted EM filters to the bell units, hopefully to eliminate any mains-borne cause, but the problem remains, whether the bells are powered by battery or USB.
I understand Hive/smart-meters ( which my house has) communicate in the 2.4GHz band, but do they also use the 433MHz band occasionally for anything, e.g. software updating or triggering some other action?
 
Have you got a ham radio operator near you?
Usually identified by the multiple aerials.
433Mhz is in the middle of the ham 70cm band, although there may be no one using it near you that's a possibility.

You could try setting the doorbell up on battery then turning off your power and wrap your smart meter in earthed foil to see if it happens again. :)

It could be your neighbours or someone a mile+ down the road (shows how hard it can be to diagnose faults like this).
 
mattylad said:
Have you got a ham radio operator near you?
Click to expand...
Thanks for the suggestion. I haven't noticed any aerials locally, other than the usual TV yagis. Besides, a ham session would normally last a reasonable time, so would likely generate more than just one or two pulses per day.
mattylad said:
It could be your neighbours or someone a mile+ down the road
Click to expand...
That's what I suspect. Some remotes are advertised as having '1000 ft range' !
 
Thanks for that useful link. It indicates that frequency-wise the smart meters shouldn't be the issue with my doorbell. It also usefully indicates that my meters' comms hub is presently in an error state.:)
 
Mains signaling ethernet adaptors could also be an issue, they put out noise/interference for a long way.

I know it's not going to work as a doorbell, but can you wrap the sounder part in foil/put it in a tin box etc. to see if it goes off?
 
I did wonder about mains signalling; hence my inclusion of an RF filter in the bell's USB supply.
I could foil-wrap the bell, but I really want it available at all times. Ghost rings are generally only one or two per day, at random times of the day or night, so it would have to be foil-wrapped for 24 hrs at least.
 
Alec_t said:
I'm getting occasional ghost rings on my wireless doorbell, day or night, but I'm not sure what is triggering them. I have two different brands of bell, but both suffer from these ghost rings. The bell/bell-push use the 433MHz band (as do various garage door openers and other remotes, so one of those is the most likely culprit).
Click to expand...

Interfering items not only need to be on the correct frequency, but generate the correct code to trigger your bells, on any reputable equipment - so I suspect your problem might be the door bells themselves. Another possibility is that someone near you is using the same door bells, with the same code selected as you - do they have an option to change the code?
 
Harry Bloomfield said:
do they have an option to change the code?
Click to expand...
Not sure. One bell has the option to change something slightly (the frequency I guess, with 12 different settings), but whichever setting is chosen the ghost rings still occur. I suppose a sufficiently high level noise pulse, containing a wide frequency range, might overwhelm any selective frequency filtering within the bell.
 
Harry Bloomfield said:
Interfering items not only need to be on the correct frequency,
Click to expand...
It is not necessary for the operating frequencies to be the same,

Side bands and/or harmonics of the transmitted RF signal can affect the operation of receiving equipment using frequencies other than the nominal frequency of the item that is causing the interference
 
bernardgreen said:
It is not necessary for the operating frequencies to be the same,

Side bands and/or harmonics of the transmitted RF signal can affect the operation of receiving equipment using frequencies other than the nominal frequency of the item that is causing the interference
Click to expand...

I am of course aware of that, but I was trying to provide the OP with a less technical reply. The point is - Interference from on frequency, harmonics, or sidebands should not trigger a bell expecting a code.

I have such a wireless door bell at my back door, and it is very loud. Never have I heard it false trigger in 10 years - yet there is plenty of RF and many frequencies here, much of it self generated.
 
You must log in or register to reply here.
Back
Top