Radio controlled clocks adjust their time and date according to a low frequency broadcast signal. This allows them to be highly accurate and to automatically adjust for daylight saving time.
These have often been referred to as "Atomic" clocks or the "Greenwich Time Signal"
In reality the UK "MSF" signal broadcasts GMT/BST (Greenwich Mean Time / British Summer Time) from Anthorn, UK. It has a range of up to 1200km. Before the 1st April 2007 the signal was transmitted from Rugby, UK.
In Europe there is another signal, "DCF", broadcasting CET (Central European Time) from Mainflingen, near Frankfurt, Germany. It has a range of up to 1500km. There is also a signal from Berne,"HGB", Switzerland, also broadcasting CET, used by the IROX range of products.
These signals can generally be received throughout the British Isles and parts of Europe, subject of course to topographic influences. Generally the signal will go through or around many obstructions but one must accept that a ferro concrete or granite obstruction might be a bit too much.
All of the products we sell in the UK will work with one or both of these signals.
An MSF only device will only tell UK time unless you either disable the RC function (if this option is available) or it is out of range of the signal.
A dual MSF / DCF device is switchable between both signals allowing it to be used throughout the GMT/BST and CET time zones.
The DCF models that we sell all have a time zone function allowing the user to select an offset from CET. For example in the UK the time zone would be -1. If your clock keeps showing an hour ahead then you have not set the time zone in the setup process.
In any case where the clock can't receive the signal or the radio controlled function is disabled you can set the clock manually and it will work as an accurate quartz clock.
If your clock doesn't pick up the signal instantly don't despair. Sometimes atmospheric contitions and on odd occasions maintenance to the clock signal may well be the cause. Also with both MSF and DCF signals, the possible operating range is greater at night. In these cases your clock will probably synchronise correctly overnight or when conditions improve.
Note:-
The radio controlled or "Atomic" function on clocks for the North American market will not work in Europe. These clocks may work as a quartz clock.
Many radio controlled clocks destined solely for the European market will only display CET, i.e. one hour ahead of UK time.
