Radio controlled clock, DCF 77
With your radio controlled clock
Sonoclock 720
,
you are in the possesion of an absolutely precise
alarm- and appointment clock which sets itself
fully automatically to the radio-transmitted time
signal of the most accurate clock in the world:
the atomic clock of the Bundesanstalt (Federal
Standards Institute) in Braunschweig/Germany
(PTB). The time deviation is smaller than 1
second in 1 million years.
Your radio controlled alarm clock Sonoclock 720
receives time 'telegrams' on the longwave band
(77.5 kHz) from the official German standard
frequency and time signal transmitter DCF 77,
located in Mainflingen (24 km south-east of
Frankfurt/Main). This transmitter has a range of
up to 1500 km.
Your Sonoclock 720 receives the DCF 77 trans-
mitter free of charge via the DCF 77 antenna in
any place where reasonable longwave reception
is possible with a good portable radio. In many
cases, your alarm clock receives the time
telegrams at a considerably greater distance
from the transmitter, but here the local reception
conditions play an important role.
The built-in microprocessor of your alarm clock
processes the received time telegrams and
controls the clock fully automatically. As soon as
reception of the DCF time signals is possible
again after an interruption, the clock will
immediately be synchronized. In addition to the
advantages of time precision and a wake-up
signal accurate to the second, the radio
controlled Sonoclock 720 adjusts itself
automatically from normal time to summer time,
and vice versa.
Positioning the set
Caution should be exercised if the set is placed
on furniture as surfaces are often coated with
lacquers and plastic finishes containing additives
which attack the material of which the feet of the
set are made, leaving stains which can only be
removed with difficulty or not at all.
Further notes:
• Only a soft cloth which picks up dust should
be used to clean the cabinet. Do not use
aggresive polishes or cleaning agents.
• Do not expose the unit to moisture (e.g.
dripping or splashing).
• The type label is on the bottom of the unit.
Light dots
6
ALARM
6
– indicates that the alarm function
is activated
DIAL
6
– Lights up when the radio is
switched on.
DCF
6
– Lights up when the DCF-Signals
have been received correctly.
Back of the set:
– AC mains cable
– External antenna for reception of the DCF 77
time signals
– Wire antenna for FM reception
INTRODUCTION
CONTROLS
8
Sonoclock 720 page 8
GB
DCF 77
ANTENNA
SNO
OZE
S O
N O
C L
O
C K
7
2 0
S
L E
E
P
ALARM
TIME
VOLUME
MW
FM
TU
NIN
G
ALAR
M
MW
FM
530
88
650
92
800
96
1000
100
1600
104
kHz
108
MHz
1800
TIME
ALARM
SNOOZE
SLEEP
VOLUME
BAND
TUNING
p
ALARM
6
DIAL
6
Battery
ɷ
y
0
RADIO
ALARM
DCF
6
DCF 77
ANTENNA
FM ANTENNA
