Operation Guide 4791
3
Radio-controlled Timekeeping Precautions
•
Strong electrostatic charge can result in the wrong time being set.
•
The time calibration signal bounces off the ionosphere. Because of this, such factors
as changes in the reflectivity of the ionosphere, as well as movement of the
ionosphere to higher altitudes due to seasonal atmospheric changes or the time of
day may change the reception range of the signal and make reception temporarily
impossible.
•
Even if the time calibration signal is received properly, certain conditions can cause
the time setting to be off by up to one second.
•
The current time setting in accordance with the time calibration signal takes priority
over any time settings you make manually.
•
If you are in an area where proper time calibration signal reception is impossible, the
watch keeps time within ±20 seconds a month at normal temperature.
•
If you have problems with proper time calibration signal reception or if the time
setting is wrong after signal reception, check the GMT differential setting.
The initial factory default GMT differential setting is GMT +1.
Transmitters
This watch is able to receive time calibration signals transmitted in Germany
(Mainflingen) and England (Rugby). The following explains how the watch determines
which transmitter it should check first.
When GMT differential GMT+1 or GMT+2 is selected:
In this case:
The first signal search
operation after the GMT
differential setting has been
changed
The second and subsequent
signal searches
The watch does this:
1. Checks the Mainflingen signal first.
2. If the Mainflingen signal cannot be received,
checks the Rugby signal.
1. Checks the signal of the transmitter of the first
receive operation (Rugby or Mainflingen).
2. If the checked signal cannot be received, checks
the other signal.
In this case:
The first signal search
operation after the GMT
differential setting has been
changed
The second and subsequent
signal searches
The watch does this:
1. Checks the Rugby signal first.
2. If the Rugby signal cannot be received, checks
the Mainflingen signal.
1. Checks the signal of the transmitter of the first
receive operation (Rugby or Mainflingen).
2. If the checked signal cannot be received, checks
the other signal.
When GMT differential GMT+0 is selected:
Timekeeping
•
The current time in the Timekeeping Mode is calculated in accordance with the
current Greenwich Mean Time (GMT) differential setting.
•
GMT differential is calculated by this watch based on Universal Time Coordinated
(UTC*) data.
* UTC is the world-wide scientific standard of timekeeping. It is based upon
carefully maintained atomic (cesium) clocks that keep time accurately to within
microseconds. Leap seconds are added or subtracted as necessary to keep UTC
in sync with the Earth’s rotation. The reference point for UTC is Greenwich,
England.