OT - Radio controlled clocks

[Mike Lane]

I wonder if anyone else has noticed that some radio controlled clocks are not keeping quite as accurate time recently. but I have two which I've noticed have been drifting apart by a few seconds over the last few days.

I've just discovered the reason which is that the NPL transmitter at Anthorn, Cumbria has been shut down since 26 March for maintenance work. It's due to go back on on Friday 6 April.

I was a bit puzzled that my watch wasn't affected until I remembered that (unlike the clocks) it's dual frequency and can receive the signal from Mainflingen, Germany as well as Anthorn

[Martin Brown]

Yes. Thanks for that. It is showing "no signal".

I changed the battery in one of mine yesterday and it has not yet been able to find a signal since. The one on German DCF77 is fine.

[Michael Chare]

My mains powered clock has not shown the correct time since we changed to BST. Your posts have made me find out why this is:

[Andy Burns]

You'd think they'd pick the maintenance windows to be a decent period

*away* from GMT/BST switch dates ...

[jgharston]

I was just chatting with somebody about this a few minutes ago. They shut down on the first Tuesday of each month and the first week of April for maintenance.

JGH

[PeterC]

I'm just glad that there's an explanation. There are 2 clocks in this room:

1 on Anthorn and the other on somewhere in Germany and I wasn't sure which was correct.

I wonder how time servers (computer type!) are adjusted, as the UK clock and the PC clock are in sync. but ~1.5s behind Germany.

[Tim Streater]

From other time servers higher up the hierarchy. The top ones are synced with atomic clocks IIRC.

[Brian Gaff]

Don't some of them also use a german transmitter though? I can also tell you something odd about a dab clock radio. Every so often it jumps back an hour for no apparent reason. Brian

[fred]

Similarly, maintenance on HMRC's VAT return submission servers appears to be carried out exclusively on the 7th of the month between 7pm and Midnight which happens to be the last 5 hours before the submission deadline for online filing .

[Mike Lane]

Brian Gaff wrote on Apr 3, 2012:

Er... yes

[Paul D Smith]

Anyone else got a 2000-odd Vauxhall with their crap built in clock? It syncs via RDS but each spring-forward/fall-back it won't sync. I've found that if the clock time is within about 5 minutes, it will resync but not anything more. So someone clearly decided "within 5 mins, good signal so sync, outside 5 mins bad signal so ignore" and forgot to also allow for the summer time leaps - doh.

Paul DS

[PeterC]

Several years ago I used NPL but then changed ...ac.uk ones. ICR why, but possibly NPL blocked unknown IPs.

[tony sayer]

In article , Mike Lane scribeth thus

Yes that does seem to be shut down quite a bit these days, seems more so than when it was at Rugby...

[Martin]

NPL accepts foreign IPs.

[Mike Clarke]

Yes, the time taken to process the original analogue input and convert to digital means that digital radio and TV transmissions run a little behind the real world.

[PeterC]

Perhaps I'll try again then. ATM it's on ntp2b.mcc.ac.uk and I do have ntp2.npl.co.uk still. Anyway, all 3 clocks are now in agreement and, I hope, correct.