In message ,
Dave Plowman wrote:

In article ,
Mark wrote:
How do these Radio controlled clocks supposed to work? I today bought a
cheap LCD rc alarm clock from Littlewoods but can't get the clock to
automatically update to the correct time. The instructions say the clock
updates itself at certain times of the day from the the signal via a
transmitter in Rugby. There's also a manual "receive" button to start
receiving the signal immediately if required (or as soon as the
batteries are inserted). The "receive" indicator will flash for about 8
minutes but then goes out without updating the clock.

It's possible it's not receiving the signal. Mine shows a steady 'receive'
indication when things are ok, flashes when it's not happy, and goes out
completely when the signal is lost.

I'd say mine is sited well to receive an LF signal but still shows no
signal at times - perhaps you could try moving yours to see if it works ok
elsewhere.


The radio station at which I used to work had a very fancy Rugby
receiving clock. Several hundred pounds worth. Of course, this was
purchased in the days before you could get one for a tenner from Argos.

It sat in Racks and had an external antenna that had to be placed as
nearly outside the building as possible as VLF is easily blocked by
structure (look at the way R4 LW disappears briefly as you pass
underneath motorway bridges. That's at 198kHz, so 60kHz is worse.)

The main point of it was to keep all the clocks in the building
precisely synchronised with each other. It was nice if they also
synchronised with the NPL! To this end it had a serial line
daisy-chained to a clock in each studio. It had its own battery backup
in case of mains failure (so that you wouldn't have to wait 5 minutes
for it to reset itself), it also had its own, laser-trimmed quartz
crystal clock so that if Rugby went off air for an extended period (the
annual maintenance *might* take it off for the complete 2 weeks rather
than off in the day and on in the night) it could keep very accurate
time, and each studio clock also had its own quartz movement so that if
the main clock failed, you had a couple of days before they became more
than a second or two out of synch.

It used to confuse the overnight jocks by fast-forwarding at GMT/BST
changes!

One presenter was severely lacking in the sight-department and as soon
as stand-alone clocks became available we had to buy a couple (at about
£40 each ISTR) so that we could put one on the desk next to him. For
some reason it seemed to get the signal better inside the building than
the "big" clock in Racks did!

Just a fun story...

Hwyl!

M.

--
Martin Angove: http://www.tridwr.demon.co.uk/
Don't fight technology, live with it: http://www.livtech.co.uk/
.... As far as we know, our computer has never had an undetected error.