41
100 meters (see notes on “Positioning” and “868
MHz Reception”).
DCF-77 RADIO CONTROLLED TIME
The time base for the radio-controlled time is a Cesium
Atomic Clock operated by the Physikalisch Technische
Bundesanstalt Braunschweig which has a time deviation
of less than one second in one million years. The time is
coded and transmitted from Mainflingen near Frankfurt via
frequency signal DCF-77 (77.5 kHz) and has a
transmitting range of approximately 1,500 km. Your radio-
controlled temperature station receives this signal and
converts it to show the precise time in summer or
wintertime. The quality of the reception depends greatly
on the geographic location. In normal cases, there should
be no reception problems within a 1500km radius of
Frankfurt.
Once the outdoor temperature is displayed on the
temperature station, the DCF tower icon in the clock
display will start flashing in the upper left corner. This
indicates that the clock has detected that there is a radio
signal present and is trying to receive it. When the time
code is received, the DCF tower becomes permanently lit
and the time will be displayed.
DCF reception is done twice daily at 02:00 and 03:00 am.
If the reception is not successful at 02:00 am, then the
next reception takes place the next hour and so on until
06:00am, or until the reception is successful. If the
reception is not successful at 06:00 am, then the next
attempt will take place the next day at 02:00 am.
If the tower icon flashes, but does not set the time or the
DCF tower does not appear at all, then please take note
of the following:
