Wireless doorbell & BT Homehub

[Allan]

Sister has had BT Homehub for a while and seems to work fine.

She recently purchased a Wireless doorbell (Byron SX-14

) for various reasons, and it seems to be interfering with the Homehub's connection (the lights go from normal/blue to brown/flashing/disconnected/reconnecting), so the Homehub looses the connection to the net. (This is completely separate from any issues that her laptop might have with the wireless connection to the router).

Apart from changing the Homehub (which is slightly draconian, but could happen in the future, but not immediately), does anyone have any suggestions on how to ensure the Homehub doesn't loose the connection.

TIA

Allan

[Jonathan]

Try changing the frequency used by one or the other. It sounds as though the doorbell radio is interfering with the router.

Jonathan

[airsmoothed]

If I'm reading this right then the problem is the ADSL link not the wireless, is it possible to increase the physical distance between the doorbell unit and the Homehub, are they connected to the same mains socket, if so try moving one of them to a different socket, just in case the problem is conducted rather than radiated.

[robgraham]

on.eu/) for various reasons, and it seems to be

That would be my diagnosis too, with the further puzzle that that bell looks somewhat similar to the Byron one I have and it is battery driven. Also my Homehub is about 3m from the door bell and less than a metre from the bell (yes, mine's a bell - can't stand these chimes things which seem really chav to me!). I certainly don't get any problems.

If this doorbell is anything like mine it has a selection of channels and I would try changing those first. As this doesn't seem to be a commonly reported problem then it's time to change either the bell or the router and as it is recently purchased then I would get the bell changed as perhaps it's radiating at a frequency it shouldn't and somehow getting to the router.

[Andy Inman]

yron.eu/) for various reasons, and it seems to be

D'oh brain fade, the doorbell will be battery operated won't it! So no chance of mains borne problems then, back to increasing RF isolation between doorbell RF transmitter and Homehub/ ADSL wiring. How close is the doorbell transmitter to the ADSL phone socket?

[Graham.]

brown/flashing/disconnected/reconnecting), so the

any issues that her laptop might have with the

in the future, but not immediately), does anyone

Actually it's very surprising indeed that a wireless doorbell operating at hundreds of megahertz is interfering with ADSL which occupies a band from a few tens of kilohertz up to less than 2,000 kilohertz

Take nothing for granted. Is it the transmitter (bellpush) that is causing the interference, or the receiver (bell unit)? take the battery out of the latter, and operate the former to test.

Can you post the make/model of the doorbell so I can perhaps see the frequencies and technologies involved?

[robgraham]

on.eu/) for various reasons, and it seems to be

ue to brown/flashing/disconnected/reconnecting), so the

te from any issues that her laptop might have with the

happen in the future, but not immediately), does anyone

g the interference,

ate the former to test.

uencies and technologies

Tut, tut, Graham, try reading the original post for the bell type ! Not such a profound observer, are you? (couldn't resist that)

[robert]

Disconnecting the orange wire on pin 3 of the telephone sockets ( which is only used on old phones for a ring signal) can reduce interference being fed into the phone wiring. see:

good instructions and explanations.

Given the interference appears to be rf and affecting the adsl signal on the phone line this would seem a sensible approach.

[Graham.]

only used on old phones for a ring signal) can reduce

phone line this would seem a sensible approach.

That's true, but I very much doubt the 433Mhz bell-push in this case is causing the interference.

half expected for the bell to be an electromechanical one acting as a spark transmitter but no such luck ;-)

I still instinctively suspect that the cause will be the mains powered receiver, rather than the transmitter button. Perhaps the OP could unplug it and see if pressing the button still causes the problem.

[Dave Liquorice]

I'd agree with that 433MHz way above the highest of the ADSL frequencies by a factor of 200 odd...

That is what I was expecting as well but it's a electronic toney thing. It does have flashing light though... What is making that light flash? What sort of light is it, xenon flash tube, LED, incandescant?

Along with the test of trying the bell push with the RX unplugged (just to make sure the 433MHz isn't a problem). Also try with the flashy light set to be on and set to be off.

[Graham.]

It's a high intensity LED according to the datasheet. The device is unlikely to have a relay switch but I suppose it is just possible.

I was also wondering if it has a poorly designed SM PSU that emits hash when under load. The OP might want to place a MW or LW receiver tuned between stations in the vicinity of the unit.

[Dave Liquorice]

That was my thoughts as well. Now I know it's a "high intensity" LED, that might not be fed with DC but with low duty cycle pulses running at at few kHz but badly/not filtered so loads of RF noise.

Yep.

[Jim]

vicinity of the unit.

I can confirm this is a likely source of the trouble. SMPSUs can switch at 100's of kHz - well within the ADSL spectrum. They should have EMC filters, but a lot of them are so cheaply made (and small in size) that I bet corners get cut. I have one that causes interference on my line. It's not bad enough to lose sync, just increase the error rate when it's switched on.