10
Introduction
Information on the DCF77 Time Signal
This radio controlled clock picks up the time information from the
Caesium Atomic Clock at the Physikalisch-Technische Bundesan-
stalt at Braunschweig/Germany. Such Caesium Atomic Clocks have
an accuracy of +/- 1 second in 1 million years. The signal is coded
and transmitted from the station at Mainflingen.
The station has an effective range of about 2000 km and broadcasts
on a frequency of 77.5 kHz. If the clock is unable to pick up the
signal, it automatically switches to quartz mode. When the clock
picks up the DCF77 signal, it readjusts itself.
DCF77 stands for
D for Deutschland (Germany), C as indicator
for a long wave signal, F for Frankfurt (Mainflingen is close to
Frankfurt), and 77 for the frequency.
Inserting/replacing the Battery
Twist the rear part of the housing counter clockwise from the
clock.
Depress the latch of the battery compartment lid and open the
battery compartment.
Insert a new battery of the type LR6 (AA) into the battery com-
partment. Pay attention to the proper polarity of the battery. The
polarity is printed inside the battery compartment. Preferably use
alkaline batteries for proper function.
Close the battery compartment with the lid.
Re-install the rear part of the housing and twist it clockwise to
fasten it. Do not use force when removing or installing the rear
part of the housing. Pay attention that the rubber sealing ring sits
properly in place.
Replace the battery with a new battery of the same type if the
display gets weaker or if the clock runs imprecisely.
