Casio 4378, 4379 World Time, Signal Reception Troubleshooting, LON, PAR, BER, ATH, ATH, BER, PAR, LON, LON, DST, DST, DST, Note, Note, Problem, Home City, Probable Cause

Receiving indicator

Operation Guide 4378 4379

•Signal reception is normally better at night than during the day.

•Time calibration signal reception takes from two to seven minutes, but in some cases it can take as long as 14 minutes. Take care that you do not perform any button operations or move the watch during this time.

Reception Ranges

1,500 kilometers
Rugby
500 kilometers	Mainflingen

•At distances further than about 500 kilometers from a transmitter, signal reception may not be possible during certain times of year or times of day. Radio interference may also cause problems with reception.

•Even when the watch is within the reception range of the transmitter, signal reception will be impossible if the signal is blocked by mountains or other geological formations between the watch and signal source.

•Signal reception is affected by weather, atmospheric conditions, and seasonal changes.

•See the information under “Signal Reception Troubleshooting” if you experience problems with time calibration signal reception.

About Auto Receive

With auto receive, the watch receives the time calibration signal automatically up to six times a day. When any auto receive is successful, the remaining auto receive operations are not performed. The start times of the auto receive operations depend on the current Home City and DST settings.

Home City		Auto Receive Start Times
		1	2	3	4	5	6
LON	Standard Time	1:00 am	2:00 am	3:00 am	4:00 am	5:00 am	Midnight
	Daylight Saving	2:00 am	3:00 am	4:00 am	5:00 am	Midnight	1:00 am
	Time						next day
PAR	Standard Time	2:00 am	3:00 am	4:00 am	5:00 am	Midnight	1:00 am
BER		3:00 am	4:00 am	5:00 am	Midnight	1:00 am	next day
	Daylight Saving						2:00 am
	Time					next day	next day
ATH	Standard Time	3:00 am	4:00 am	5:00 am	Midnight	1:00 am	2:00 am
		4:00 am	5:00 am	Midnight	1:00 am	next day	next day
	Daylight Saving					2:00 am	3:00 am
	Time				next day	next day	next day

Note

• Auto receive is performed only if the watch is in the Timekeeping Mode or World

Time Mode when one of the calibration times is reached. It is not performed if a

calibration time is reached while an alarm is sounding, or while you are configuring

settings (while settings are flashing on the display).

• When a reception starts, the second hand will move at high speed to the 12 o’clock

position where it will stop until the reception is complete.

• Auto receive of the calibration signal is designed to be performed early in the

morning, while you sleep (provided that the Timekeeping Mode time is set correctly).

•Time calibration signal reception normally takes from two to seven minutes, but in some cases it can take as long as 14 minutes. Take care that you do not perform any button operations or move the watch during this time.

•After signal reception is complete, the display of the watch changes to the last signal screen.

Note

•To interrupt a reception and return to the Timekeeping Mode, press D.

•If the reception is unsuccessful, the message ERR appears on the display for about one or two minutes. After that, the watch returns to the Timekeeping Mode.

•You can also change from the last signal or ERR screen to the normal timekeeping screen by pressing D.

To turn auto receive on and off

1. In the Timekeeping Mode, press Dto display the Last

On/Off status	Signal screen.
	2. Hold down Auntil the current auto receive setting (ON
	or OF) starts to flash. This is the setting screen.
	• The second hand will move at high speed to the 12
		o’clock position, where it will stop.
	•	Note that the setting screen will not appear if the
		currently selected Home City is one that does not
		support time calibration reception.

3. Press D to toggle auto receive on (ON) and off (OF).

4. Press A to exit the setting screen.

• The second hand will advance at high speed to the correct position in accordance with the digital time seconds count, and resume normal movement from there.

• For information about city codes that support signal reception, see “To set your Home City”.

Signal Reception Troubleshooting

Check the following points whenever you experience problems with signal reception.

Problem	Probable Cause	What you should do
Cannot perform	• The watch is not in the Timekeeping Mode.	• Enter the Timekeeping Mode
manual receive.	• Your current Home City is not one of the	and try again.
	following city codes: ATH, BER, PAR, or	• Select ATH, BER, PAR, or
	LON.	LON as your Home City.
Auto receive is	• You changed the time setting manually.	• Perform manual receive or
turned on, but	• The watch was not in the Timekeeping	wait until the next auto
the Level 4	or World Time Mode, or you were	receive is performed.
receiving	performing some button operation	• Check to make sure the
indicator does	during auto receive.	watch is in a location where it
not appear on	• Even if reception is successful, the	can receive the signal.
the Timekeeping	Level 4 receiving indicator disappears
Mode display.	each day when the first auto receive
	operation of the day is performed.
	• Time data (hour, minutes, seconds) only
	was received during the last reception.
	The Level 4 receiving indicator appears
	only when time data and date data
	(year, month, day) are both received.
Time setting is	• If the time is one hour off, the DST	• Change the DST setting to
incorrect	setting may be incorrect.	Auto DST .
following signal	• The Home City code setting is not	• Select the correct Home City
reception.	correct for the area where you are using	code.
	the watch.

•For further information, see “Important!” under “Time Calibration Signal Reception” and “Radio-controlled Timekeeping Precautions”.

World Time

Before going to bed for the night, remove the watch from your wrist, and put it in a

location where it can easily receive the signal.

• When auto receive is turned on, the watch receives the calibration signal for two to

seven minutes everyday when the time in the Timekeeping Mode reaches each of

the calibration times. Do not perform any button operation within seven minutes

before or after any one of the calibration times. Doing so can interfere with correct

calibration.

• Remember that reception of the calibration signal depends on the time kept in the

Timekeeping Mode. The receive operation will be performed whenever the display

shows any one of the calibration times, regardless of whether or not the

Timekeeping Mode time actually is the correct time.

About the Receiving Indicator

The receiving indicator shows the strength of the calibration signal being received. For best reception, be sure to keep the watch in a location where signal strength is strongest.

City Code

Current time in the selected city code

The World Time Mode digitally displays the current time in 30 cities (29 time zones) around the world.

•Pressing Ain the World Time Mode causes the applicable city code to appear on the digital display for about two seconds.

•If the current time shown for a city is wrong, check your Home City time settings and make the necessary changes.

•The watch will perform a signal reception even if it is in the World Time Mode when a calibration time is reached. If this happens, the World Time Mode time settings will be adjusted in accordance with the Timekeeping Mode’s Home City time.

•All of the operations in this section are performed in the World Time Mode, which you enter by pressing C.

Receiving indicator

Weak	Strong
(Level 1)	(Level 4)

•Even in an area where signal strength is strong, it takes about 10 seconds for signal reception to stabilize enough for the receiving indicator to indicate signal strength.

•Use the receiving indicator as a guide for checking signal strength and for finding the best location for the watch during signal reception.

•The Level 4 receiving indicator indicates that at least one of the auto calibration signal receive operation was successful. Note, however, that the Level 4 receiving indicator is cleared from the display when the first auto receive operation of the day is performed.

•The Level 4 receiving indicator appears on the Timekeeping Mode’s Receiving Indicator and Seconds Count screen only. The Level 4 receiving indicator is not displayed if signal reception was unsuccessful or after manual adjustment of the current time setting.

To perform manual receive

1. Place the watch on a stable surface so its top (12 o’clock side) is facing towards a window.

2. In the Timekeeping Mode, hold down Dfor about two

seconds until the watch beeps.

3. Release D and RC flashes to indicate that signal

reception has started.

• When a reception starts, the second hand will move at

high speed to the 12 o’clock position where it will stop

until the reception is complete.

To view the time in another city

While in the World Time Mode, press Dto scroll through the city codes (time zones).

•For full information on city codes, see “City Code Table”.

To toggle a city code time between Standard Time and Daylight Saving Time

	1. In the World Time Mode, use Dto display the city code
DST indicator	(time zone) whose Standard Time/Daylight Saving Time
	setting you want to change.
	• Pressing Ain the World Time Mode causes the
	applicable city code to appear on the digital display for
	about two seconds.

2. Hold down Ato toggle Daylight Saving Time (DST indicator displayed) and Standard Time (DST indicator not displayed).

•Note that you cannot use the World Time Mode to change the DST setting of the Home City code you currently have selected in the Timekeeping Mode. See “To change the Daylight Saving Time (summer time) setting” for information about turning the Home City code DST setting on and off.

•The DST indicator will appear on the display whenever you display a city code for which Daylight Saving Time is turned on.

•Note that you cannot switch between Standard Time and Daylight Saving Time while GMT is selected as the city code.

•Note that the DST/Standard Time setting affects only the currently displayed city code. Other city codes are not affected.

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