Ohtakadoya-
yama transmitting
station（40 kHz）
1,000km
1,000km
■ Radio signal reception range : Japan (JJY)
JJY is operated by the National Institute
of Information and Communications
Technology （NICT）.
JJY is transmitted from two stations in
Japan. Each station transmits JJY in a
different frequency.
F u k u s h i m a （ O h t a k a d o y a - y a m a
transmitting station: 40 KHz）
Kyushu （Hagane-yama transmitting
station: 60 KHz）
※ NICT：National Institute of Information and
Communications Technology
※ Whether the watch succeeds in receiving
radio signals or not depends on the receiving
conditions.
Refer to "About reception environment" on
P.108.
The reception range from each transmitting station is approximately
1,000 km （1,000 km radius of each station）.
Hagane-yama
transmitting
station（60 kHz）
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Reception environment
This watch receives standard radio signals from Japan (2 stations), China, U.S.A. and Germany.
A radio signal transmitting station can be selected by time difference adjustment function.
→ Setting the time difference (selecting a radio signal transmitting station) P.118
Japan (JJY)
P.103
China (BPC)
P.104
U.S.A.
(WWVB)
P.105
Germany
Germany
Germany
Germany
Germany
(DCF77)
P.
P.
P.106
■ Radio signal reception range indication
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※ When the time difference is set for a region other than radio signal reception range, a radio signal cannot be received.
Check the setting of the time difference → Setting the time difference (selecting a radio signal transmitting station) P.118
※ Radio signal reception results depend on a receiving environment. → Environments in which it is
difficult to receive a radio signal P.108
※ The watch cannot receive a radio signal outside the radio signal reception range. → Radio signal
reception range indication P.102
※ When the watch does not display the correct time and date even after successfully receiving a radio
signal. → Troubleshooting: Misalignment of the time and hands P.154, Misalignment of date P.156
・ Manual reception
This watch can receive a radio signal arbitrarily at any time other than the
automatic reception mode.
→ How to conduct manual reception P.140
・ Automatic reception
This watch sets the time and date by automatically receiving a radio signal at a fixed time.
This watch automatically receives a radio signal before 2:00 a.m. and 4:00 a.m.
■ Automatic reception and manual reception
※ When the reception is successful, the watch finishes the automatic reception.
・ Place the watch in a place where it can easily receive a radio signal (by the window, etc.)
・Do not move the watch during the radio signal reception.
→ To Improve Radio Signal Reception P.107
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Radio-controlled watch
Receive radio signals
through the antenna
inside the watch
↓
Analyze time
information
↓
Display the current
Time and Date
The radio-controlled watch displays the precise Time and Date by automatically
receiving and synchronizing itself with the radio signal of an official standard frequency.
Transmitting
Station
Cesium
Atomic Clock
■ Mechanism of radio signal reception
Setting the Time and Date by Receiving a Radio Signal
Time signal transmitted by a standard frequency is based on a super accurate "Cesium
Atomic Clock" that may have a 1 second loss or gain per one hundred thousand years.
Official standard
frequency
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