Tuesday, 3 December 2013


Picture the scene if you will. Night has fallen, I’m reading my Kindle in front of a gently crackling log burner - all very pleasant.

Maybe I’ll have a glass of something later, but for some reason I check the digital thermometer. This little gadget tells me it is chilly outside, but a comfortable 22°C inside. Most satisfactory.

The digital thermometer has one of those radio-controlled clocks, supposedly accurate to the second. It claims the time is 10:05pm which is later than I thought. Rather odd too, because the grandfather clock ticking away in the corner of the room says the time is about 9.30. It doesn’t do am or pm, being about 250 years old.

So I sigh, get up from my chair and open the grandfather clock case to check the pendulum is swinging. Although I already know it must be swinging because I can hear that lovely peaceful tick – and it is – nothing wrong there.

Now in spite of the formidable accuracy of radio-controlled clocks, if an ancient grandfather clock goes wrong it tends to stop and that’s that - all pretty obvious. If the thing is ticking away like a good 'un, it is most unlikely to be wrong by as much as 35 minutes. Clockwork regulated by a pendulum just doesn’t tend to do that.

So I compare the digital thermometer clock to other clocks in the house and sure enough the grandfather clock is right and the digital thermometer wrong. Yet by the following morning it had corrected itself.

I’ll never know why of course. A modern gadget goes wrong – nobody knows why – chuck it away and buy another.


Woodsy42 said...

A friend once bought an early radio controlled clock. He kept it on top of his TV. It was always wrong!

A K Haart said...

Woodsy - I suppose it's a golden rule of gadgets - never buy the early models.

Nigel Sedgwick said...

Well, (nearly) everything has a reason, though sometimes it is just too much effort to finalise the diagnosis. More than one problem at a time can be particularly confusing, even for those trained in testing and fault diagnosis. This is especially the case where there are no or few useful warning lights etc.

See the Wikipedia page on Radio Clocks and note that there looks to be only one UK-based transmitter, at Anthorn and using the MSF signal protocol. That signal is managed by the National Physical Laboratory who have some useful information available on outages etc.

Note in particular item 4 (including checking the battery), item 5 (particularly on poor radio reception) and item 6 (stating many battery-powered clocks only check the time every hour or two).

I hope this helps, at least to the extent of not chucking away an item that is still working: but just needs some combination of a new battery, repositioning and a bit of patience before it resynchronises.

Best regards

Demetrius said...

Hephaestus hasn't quite got the hang of this digital thing yet.

A K Haart said...

Nigel - I won't throw it out because the thermometer function still works and the clock is now correct. The position has never changed, but if it happens again I may change the battery.

Demetrius - and I hope he never does.