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Operation Guide 3707
2
How a Radio-controlled Watch Works
What is a radio-controlled watch?
Your radio-controlled watch is designed to receive a time calibration signal that contains standard
time data, and adjust its current time setting accordingly.
Signal data
Transmitter
Internally
Decode
Watch
Time data
Long-wave
time
calibration
signal
Cesium
atomic clock
Signal is received
using built-in antenna.
Watch decodes
received data
and converts it
to time data.
Time is adjusted
according to
time data.
Calibration Signal
• The Japanese calibration signal (Call Sign: JJY) is maintained by the National Institute of Information
and Communications Technology (NICT). It is a long wave signal transmitted 24 hours a day from the
Mt. Otakadoya transmitter (40kHz) located in Tamura-gun, Fukushima Prefecture, and from the Mt.
Hagane transmitter (60kHz) located on the border between Saga Prefecture and Fukuoka Prefecture.
Note that transmission of the time calibration signal may be interrupted occasionally due to
maintenance, lightning, etc.
Reception Range
This watch is designed to receive either the Mt. Otakadoya signal (40kHz) or the Mt. Hagane signal
(60kHz), whichever is strongest.
• Under optimum conditions, the calibration signal should be receivable up to 1,000 kilometers from the
transmitter. Note that the wave is relatively weak at distances greater than 500km, so reception may
be poor at long distances.
• Geographic contours, nearby buildings, seasonal conditions, the time of day, can even make reception
impossible even when you are within range of the transmitter.
• Reception is best at night.
1000km
Mt. Hagane
(60kHz)
Mt. Otakadoya
(40kHz)
500km
1000km
500km
Transmitter Locations
Location
Reception is difficult and may even be impossible in the locations described below. Avoid such
locations when performing signal reception.
• You should think of your watch operating like a radio or TV when it is receiving the calibration signal.
If you are experiencing problems with reception, move away from the types of locations described
above to a location with better reception, and try again.
Receiving the Calibration Signal
There are two methods you can use to receive the time calibration signal.
Auto receive (Reception is performed automatically at midnight, 1:00, 2:00, 3:00 and 4:00 each
morning.)
• Auto receive is terminated as soon a reception is successful.
• If auto receive is not successful for any of the normal auto receive operations shown above, auto
receive is performed one more time at 5:00 a.m.
• Successful auto receive keeps timekeeping accurate.
Manual receive (You initiate reception using a button operation.)
❚
To position the watch for optimum reception
Remove the watch from your wrist and place
it somewhere so its right side (9 o’clock side,
where the antenna is located) is facing a
window.
• Do not move the watch while it is receiving
the calibration signal.
❚
Time Required for Reception
A calibration signal receive operation takes
anywhere from about two to seven minutes.
❚
To perform manual receive
In any mode, hold down the
BB
BB
B button for about two
seconds.
• The second hand will move to READY, and signal reception will
start.
❚
To interrupt reception
Press any button. This will cause the watch to return to the Timekeeping Mode.
❚
When reception is successful
The watch will terminate reception and adjust the current time. Next the second hand will move to
GET.
❚
When reception is not succesful
The second hand will move to NG (No Good), without adjusting the time setting.
• After the second hand is pointing at GET or NG, the watch will return to the Timekeeping Mode if you
press any button or if you do not perform any operation for about one or two minutes.
❚
Hand Operation During Signal Reception
Second Hand .....................The second hand moves to READY when the reception operation starts,
indicating that the watch is getting ready to receive. It points to WORK
while actual reception is in progress.
Hour and Minute Hands ...The hour and minute hands continue to operate normally.
Note that the second hand does not move during signal reception.
❚
To check the result of the last signal receive operation
In the Timekeeping Mode, press the
BB
BB
B button. This
enters the Receive Result Mode.
• If the watch was able to perform a successful signal receive
operation since midnight, the second hand will move to GET. If
the watch has been unable to receive any signal successfully,
the second hand will move to NG.
• To return to the Timekeeping Mode, press the B button twice.
• The watch will also return to the Timekeeping Mode if you do not
perform any operation for about one or two minutes.
Calibration Signal Reception Precautions
• Auto reception can be performed while the watch is in the Timekeeping Mode only.
• If the hands become misaligned for some reason, they may not indicate the correct time, even if the
time calibration signal is received normally. If this happens, use the procedure under “Adjusting Home
Positions” to adjust the home positions of the hands and the date.
• Pressing any button while auto reception is in progress will cause reception to stop.
• This watch is designed to adjust its current time setting in accordance with the calibration signal
transmitted in Japan only. It operates like a standard (non-radio controlled) watch outside of the range
of the receivable time calibration signal transmitters.
• When the watch is unable to receive the time calibration signal for some reason, timekeeping accuracy
is within ±20 seconds per month.
• Proper reception may be impossible if there is something blocking the signal.
• The watch’s calendar shows dates up to the year 2099. Attempting a receive operation after that
causes an error.
After the watch receives the
Standard Time signal, it
performs internal calculations
to determine the current time.
Because of this, there may be
an error of up to one second
in the displayed time.
In a location where there is
radio interference (construction
site, airport, etc.)
Near mountains
Inside a vehicle
(automobile, train, plane, etc.)
Next to a household appliance or
office equipment (TV, speaker,
fax, computer, cell phone, etc.)
Among or near buildings Near high-voltage lines
READY
9 o’clock
side
Or
GET