We have several radio controlled clocks here, that get their signal from the 60kHz transmissions of MSF, located at Anthorn in Cumbria. For a couple of days now, the signal appears to be off air, as our clocks have all lost synchronisation. Looking at the NPL website, there is no announcement of an outage and the emails and phone calls have gone unanswered, so I'm wondering if anyone else is having a problem..? If it was just one clock, I'd suspect that, but we have about 9 or 10 of them here and they're all the same.

Did someone install new electronics (powerline LAN systems, solar power converters etc) near you? Or perhaps some of your own electronics? A particularly cheaply designed HF ballast can do it.

Certain electronics can puke out tremendous loads of interference. Solar power converters can be completely 'clean' but one of the things you have to do to make them clean, is to run cables next to each other and not in a loop over the roof to avoid making them work as transmitter antennas. In general, if solar converters are the issue, usually the interference gets less after sunset. No guarantee, though.
The worst solar setups i've encountered would already start interfering about 300m away, and could interfere both with AM/medium wave broadcast as well as with digital VHF emergency services.

I checked - currently the MSF signal is still audible, checked on a web SDR/receiver: http://websdr.ewi.utwente.nl:8901/

So the issue is either electronics in your house. Turn off all breakers in your house, then hit the sync button on the clock. Does it work now? Flip on one half of your breakers. Still works? Turn on half of the other half of the breakers. No sync anymore? It's on one of the circuits you just turned on.

No sync, even with your own power shut off? Then the problem is dirty electronics somewhere else in your block of houses. You can call Ofcom for that, i think. Electronics shouldn't interfere with such a strong signal.

In theory you can modify a clock to give it a headphone output if you add a little AM detector and an amplifier so you can hear the interference. That way you can use the directional built in antenna to triangulate the source of the interference.  If it turns out to be the neighbors and you have a good relationship with them, it might be a better idea to just help them solve the problem, rather than sending the authorities to them.

If you have a ham radio operator near you, they'd likely be delighted if they can help with the right receiver to help triangulate the source, and feel Very Important. Especially because we're all quite concerned with keeping the RF spectrum free of pollution. It's like what light pollution is to astronomers.

Hmmm. We have no solar panel installations anywhere nearby, and we have changed nothing on our own systems. So whatever it is has to be coming from outside. No idea what, though. We are licensed radio amateurs, but we don't have anything that receives that low, all our stuff is VHF/UHF, so not sure 

You can try an oscilloscope to find what is going on. Depending on the receiver design (I see these in UK tends to be some little boards with a potted chip) you can probe the signal near RF amplifier out in a discrete circuit, or at least for demodulated pulses at integrated chip digital out.


Some modern sound cards capable of running at 192KHz sample rate have enough bandwidth to capture 60KHz signal directly, provided with large enough antenna with some crude bandpass filtering. You can see the spectrogram in Audacity etc..

A much simpler approach may be just to take the clock outside to some RF quiet place like a park or a field and see if it revives!




 

Like I said, we have multiple clocks and they're all affected. Nothing has changed with regard to our equipment, no new kit plugged in or anything. It's a mystery 

Switching power supplies around are very unforgiving to anything radio, especially on LW band. You can think of 60kW transmitter some hundreds km away and neighbor's 5kW inverter heat pump running a few meters away. Even with some anti-interference filtering in place, basic square propagation law is unfavorable for distant transmitter, cause both transmitter and inverter work at about the same frequency.


Have you verified that the clock still can sync when moved outside, even preferable out of the city?

 

Another idea may be to use a small transistor radio tuned at the beginning of LW band in an attempt to locate an offender who poisons LW frequencies. Of course broadcasting LW starts a bit higher, but inverter RF hash is typically very wideband to hit even VHF frequencues.
 

66kHz is quite popular choice of working frequency of many smaller (100W and below) power supplies. If some of them drifted away a bit (due to aging components,...) you have quite strong emitter.
However we are talking here mainly about near magnetic field coupling, so such disturbance has very limited range (vs the far field from the large antenna of the time transmitter), so the culprit is most likely somewhere within the house.

Directly observing the signal by the oscilloscope on the antenna in the normal commercial clock receivers won't work, it is not that strong there (few 10's of uV, the antennas are just too small; it is good enough to be well above the noise of the receiver itself, the reception is mainly governed by the noise in the environment and there the antenna size has no effect at all, so the most compact, so cheapest designs win).
But you may look on the pulse output - a trace going from the receiver IC to the main clock IC, to see what is happening there.

We just want to know if anybody out there is experiencing the same problem as us. 
We are not electronic engineers, so any fault finding is out of the question. 

Verfied again, MSF is still happily beeping away on 60khz. S9+20dB in the eastern part of the Netherlands. Plenty strong.

In that case your only way out of this mess is to call Ofcom, because as far as i know they're the ones who deal with radio interference complaints (which this is, probably) in the UK.

At the very least take some clocks outside, 100-200m away from your current location and see if they sync there. If yes, the problem is really somewhere inside or around your house.

You don't have to be an engineer to follow the steps. Take clocks out. Fixed? Then continue at home to turn off all the circuit breakers. Yes, really, even if you think nothing has changed. You never know if some crappy chinese Daim capacitor in a mains filter has gone open circuit. Faults like that don't influence if the device it's in works or not - but it can cause interference to others.

And if you can't find the issue yourself, ask a fellow ham. If Ofcom is comparable to what we have in the Netherlands, they're not likely to do much because they're more concerned with protecting the financial interests of commercial transmitters, and with interference to emergency services.

I would add my two-cent worth here.  If your radio-controlled clock is portable, try to take it to outside to see if this works.

All we want to know is whether anyone else in the UK is having the same problem. That's it. We just want to know if we're on our own with this. Can someone in the UK reply, please..?