On 27/06/2015 22:38, Jeroni Paul wrote:
N_Cook wrote:
Anyone any insight into this error? Yesterday , coincidently? the
longest day. Set the alarm function for 06:30. Luckily woke just after
06:00 and decided to get up . Synchronous mains clock read 06:08 but
radio-code clock read 04:08, minute and seconds agreeing with another
radio-code clock but it had decided to go east 2 time zones. Still like
that about 07:00 but on returning in the evening the erroneous clock had
reset itself. How to predict when this error will reoccur? any
amelioration, plenty of LCD contrast so presumably the batteries are ok?

I live in a fringe reception area for the german time signal at 77.5kHz and have many clocks that use this signal but because a marginal reception they do not always sync. The curious thing about this is every night I have a different set of clocks sync, they seem to decide at random when the signal was good enough.

The oldest one is 13 years old and is an alarm clock I check daily, in these years I have had it three times take an incorrect time/date probably from interference. It either takes the right time or does not sync, three times in 13 years seems not bad for the simple parity bit protection the protocol uses.

I think, however, it is somewhat dangerous to have the clocks sync at night *after* you have checked they are set correctly, so if bad reception sets wrong data they will fail to wake you up at the right time.


Have you had the situation of the displayed time jumping by an hour or two?
As an alarm clock, losing synch and drifting a second or two , to a
background quartz crystal clock, is no great problem