25
DCF 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 weather 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 1,500 km radius of Frankfurt.
DCF reception is done twice daily at 02:00 and 03:00 am.
If the reception is not successful at 03:00 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:
•
Recommended distance to any interfering sources
like computer monitors or TV sets is a minimum of
1.5 - 2 meters.
•
Within ferro-concrete rooms (basements,
superstructures), the received signal is naturally
weakened. In extreme cases, please place the unit
close to a window and/ or point its front or back
towards the Frankfurt transmitter.
•
During nighttime, the atmospheric disturbances are
usually less severe and reception is possible in most
cases. A single daily reception is adequate to keep
the accuracy deviation below 1 second.
