Conrad 67 17 16 Bedienungsanleitung Seite 21

DCF introduction
The radio-controlled table clock with light sensor receives the DCF signal, which
means that the time and date are set automatically. Therefore, you do not have to
set the time and date manually. The time is synchronised with the DCF signal to that
of the caesium atomic clock at "Physikalisch Technischen Bundesanstalt" in Braun-
schweig. This results in very high accuracy. Even if there is no reception, the clock
is still a highly accurate quartz clock.
What is DCF?
The DCF signal is a coded signal that contains the time information of the caesium
atomic clock at PTB Braunschweig. This atomic clock is so precise that it deviates
theoretically +/- 1 second in one million years.
The DCF signal is coded and transmitted via a transmitter in Mainflingen near
Frankfurt. The transmitter has a range of approx. 1,500 km. Clocks with integrated
DCF receivers can receive and decode the DCF signal within range of this radio sig-
nal. For these clocks, manually setting the time is not necessary (e.g. when chang-
ing from winter to summer time).
Just like radio reception, reception of the DCF signal strongly depends on the place
and location as well as on interference signals emitted e.g. by computers, TV sets or
microwave ovens. Rooms constructed from steel-reinforced concrete may also cause
a bad reception of the DCF signal.
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