Operation Guide 4343
How a Radio-controlled Watch Works
Receiving the Calibration Signal
There are two methods you can use in order to receive the time calibration signal.
At the start of the receive operation
• The indicator hand will move to “READY”. |
What is a radio-controlled watch?
A
Signal is received by
Transmitter 
Watch decodes received data and
Signal data 
converts it to time data.
| Decode |
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Cesium | Time data | Time is adjusted | |
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atomic clock Watch | Internally | according to time | |
data. | |||
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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.
Calibration Signal
•The Japanese calibration signal (Call Sign: JJY) is maintained by the National Institute of Information and Communications Technology (NICT). It is transmitted 24 hours a day from the Mt. Otakadoya transmitter (40 kHz) located in
•The U.S. calibration signal (Call Sign: WWVB) is transmitted by the National Institute of Standards and technology from Fort Collins, Colorado.
•Time calibration signal frequencies and transmitter locations are subject to change.
The time data of the Japanese calibration signal (Call Sign: JJY) is maintained by the Japan Standard Time Group of the National Institute of Information and Communications Technology (NICT). Note that transmission of the standard wave may be interrupted occasionally due to maintenance, lightning, etc. For more information, visit the website of the Japan Standard Time Group of the National Institute of Information and Communications Technology (NICT) at the following URL.
http://jjy.nict.go.jp
•Note that the above URL is subject to change.
Auto Receive
Up to six times per day
(Midnight, 1:00, 2:00, 3:00, 4:00, and 5:00 a.m.)
•As soon as one auto receive is complete, all subsequent auto receives for that day are cancelled.
Manual Receive
You initiate signal reception by pressing a button.
Hold down the Abutton for about two seconds.
• The indicator hand will indicate |
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the result of the reception, the |
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watch will beep, and the indicator | 30 |
hand will move to “READY”. |
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| READY |
❚To interrupt a receive operation
Press any button.
• | The hour and minute hands will remain at their normal positions. |
• | The second hand will stop at “0”. |
While reception is in progress
•The indicator hand will move to “WORK”.
•The hour and minute hands will remain at their normal positions.
•Do not perform any watch operations while signal reception is in progress.
Y: Successful
N: Unsuccessful
30
WORK
WORK
When reception is complete (Signaled when the watch beeps.)
•When the receive operation is successful, the indicator hand moves to “Y”, the watch adjusts its time, and then the indicator hand returns to its second hand operation after about one or two minutes.
•When the receive operation fails, the indicator hand moves to “N” and then the watch returns to the unadjusted time after about one or two minutes.
❚To check the result of the last receive operation
In the Timekeeping Mode, press the Abutton to renter the Receive Result Mode, which displays the last receive result.
•The indicator hand will move to “Y” (if the last reception was successful) or “N” (if the last reception was unsuccessful).
•Press the Abutton to return to the Timekeeping Mode.
•The watch also will return to the Timekeeping Mode automatically if you do not perform any operation for about five seconds.
Y: Successful
N: Unsuccessful
30
The last receive status changes each time a new time calibration signal receive operation is performed.
❚To position the watch for optimum
reception
Remove the watch from your wrist and place it somewhere so its top (12 o’clock, where the antenna is located) is facing approximately in the direction of the signal transmitter. Keep it away from metal objects.
Resin Band
Metal Band
•Orienting the watch so it is sideways to the transmitter makes it more difficult to receive the signal.
•Do not move the watch while it is receiving the calibration signal.
Time Required for Reception
Signal reception normally takes anywhere from about two to seven minutes. Under certain signal conditions however, the receive operation can take as long at 14 minutes.
Reception Ranges
This watch is designed to receive the standard time calibration signal of Japan (JJY) or of the United States (WWVB). The signal that is received depends on the current Home City setting.
•For information about selecting a Home City, see “Changing the Home City Setting”. See the “World Time City Code List” for information about city codes.
Home City (Supports signal reception) | Receivable Transmitter |
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TYO, HKG | Either the Mt. Otakadoya signal (40 kHz) or the Mt. Hagane signal (60 kHz) |
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HNL, ANC, LAX, DEN, CHI, NYC | Ft.Collins |
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•Signal reception is possible in Hong Kong (HKG), Honolulu (HNL), and Anchorage (ANC) when reception conditions are good.
Transmitter Location | 1000km | Transmitter Location |
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500km |
| Mt. Otakadoya |
| 1000km |
500km | (40 kHz) |
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Mt. Hagane |
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(60 kHz) |
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| 3000km | Ft.Collins |
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1000km
Certain conditions can make reception impossible even when the watch is within one of the reception ranges shown above.
Signals become weaker outside of the smaller circles indicated by dashed lines, so the reception environment has a greater effect on signal reception.
•The following also can affect signal reception: geographic contours, structures, weather, climate, time of day (afternoon, evening), noise.
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