4.2 DCF77 Receiver
An external ferrit antenna is used to receive the signal from DCF77 and supplies it to the on-board LF receiver
where it is demodulated by a straight detector with automatic gain control. The demodulated time marks are
fed to the clock’s microprocessor.
4.3 Mounting the Antenna
Generally it is important to position the antenne in an optimal way. The antenna should be aligned at a right
angle to the direction of the transmitter (Frankfurt). It should be mounted at least 30 centimeters away from the
clock unit and from solid steel. A distance of several meters is recommended to all TVs or computer monitors.
In order to get the maximum signal, the antenna should be aligned in two steps. First it should be turned
slowly until the modulation LED is flickering irregula or mostly off. Finally the antenna must be turned by 90
◦
from this position to obtain maximum signal. After the antenna has been well adjusted the modulation LED is
blinking exactly once per second (except the 59th. second) and the free-run indication (a dot behind the second
digits) will disappear after 3 minutes at least.
16
Date: 28th October 2019
ANZ14/ANZ14DCF/ANZ14NET
Содержание ANZ14
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