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Need help?Do you have a question about the Casio 4766 and is the answer not in the manual?
Explains how to charge the watch battery using light and the importance of exposure.
Details why analog hands might stop moving and the power saving mode.
Provides information about the manual's structure and button operation indicators.
Covers manual receive, status checks, transmitter changes, and time/date adjustments.
Explains automatic time adjustment via calibration signals and manual setting procedures.
Guides on how to set the Home City for accurate time calibration.
Details on how DST affects time settings and automatic/manual adjustments.
Describes automatic and manual methods for receiving time calibration signals.
Provides guidance on watch positioning and conditions affecting signal reception.
Lists Home City codes and their corresponding time calibration signal transmitters.
Details the geographical range for signal reception and factors causing interference.
Addresses common problems like failed reception and incorrect time settings.
Explains how to start, stop, and reset the stopwatch for elapsed time measurement.
Details how to initiate stopwatch measurements directly from the Timekeeping Mode.
Shows how to display current times for 27 cities across 29 time zones.
Explains how to switch between Standard Time and Daylight Saving Time for a city.
Describes how to exchange Home City and World Time City settings.
Procedure to adjust the home position of the timekeeping and stopwatch second hands.
Guides on adjusting the home positions for hour, minute, and 24-hour hands.
Details the process for setting the home positions of the day of the week and date.
How to select the Home City and adjust Daylight Saving Time settings.
Step-by-step guide to manually set the current time, date, and day of the week.
Explains the watch's solar cell and rechargeable battery system for power.
Details the three battery power levels and their impact on watch functions.
Important warnings about watch temperature during charging and burn risks.
Describes how scrolling works in setting modes and auto-return features.
Notes on electrostatic charge, ionosphere, signal bounce, and time setting accuracy.
Information on year range, automatic calendar, and GMT differentials.
Explains how power saving enters sleep states and affects watch functions.
Methods to wake the watch from its power saving sleep state.
Lists city codes, their UTC differentials, and other major cities in the same time zone.
This document describes the operation and features of a CASIO watch, model 4766, which is a radio-controlled atomic timekeeping device.
The watch is equipped with a solar cell and a special rechargeable battery, eliminating the need for regular battery replacement. It charges when exposed to bright light, and its battery level is indicated by the movement of the analog hands. Normal operation occurs at Level 1, while Level 2 indicates low battery with the second hand jumping every two seconds and time calibration signal reception disabled. At Level 3, all functions are disabled, and settings return to factory defaults. The watch maintains internal timekeeping for about one month after dropping to Level 3.
The core function of this watch is radio-controlled atomic timekeeping. It receives time calibration signals to automatically update its time setting. Supported signals include those from Germany (Mainflingen), England (Rugby), United States (Fort Collins), and Japan (Fukushima or Fukuoka/Saga). The watch performs auto receive up to six times a day, with successful reception canceling subsequent attempts. Manual receive is also possible. The reception schedule depends on the selected Home City and whether Standard Time or Daylight Saving Time is active. The watch is designed to update the date and day of the week automatically from January 1, 2001, to December 31, 2099, and can differentiate between leap years and non-leap years.
The watch features a Timekeeping Mode for setting and viewing the current time and date, including manual adjustments. It also has a World Time Mode that displays the current time in 27 cities (29 time zones) around the world. A unique feature allows swapping the Home City with the currently selected World Time City, which is useful for frequent travelers.
A Stopwatch Mode is included for measuring elapsed time, with a display range of 59 minutes, 59.95 seconds. The stopwatch continues to run, restarting from zero after reaching its limit, until stopped. It cannot be switched to another mode while an elapsed time operation is in progress.
The watch incorporates a Power Saving feature that automatically enters a sleep state when left in the dark for a certain period. This includes "second hand sleep" (second hand stops) and "function sleep" (all functions, including analog timekeeping, disabled). The watch will not enter sleep state between 6:00 AM and 9:59 PM, but if already in sleep state, it will remain so.
To ensure optimal performance, the watch should be kept exposed to bright light as much as possible. When not worn, it should be positioned with its face pointed at a light source. Even partial blockage of the solar cell can significantly reduce charging efficiency.
Setting up the watch involves specifying a Home City, which is the city where the watch will normally be used. This is done in the Timekeeping Mode by holding down button A for about five seconds until the stopwatch second hand moves to the city code. Button D is then used to cycle through city codes. The watch automatically adjusts hands and date display for the selected city.
Daylight Saving Time (DST) settings can be managed in the Timekeeping Mode. The watch supports Auto DST for specific Home City codes, automatically switching between Standard Time and DST based on received signals. Manual switching between Standard Time and DST is also possible in the World Time Mode for the currently displayed city code.
For time calibration signal reception, the watch should be positioned with its 12 o'clock side facing towards a window, away from metal objects, vehicles, buildings, household appliances, office equipment, mobile phones, construction sites, airports, high-tension power lines, or mountains. Signal reception is generally better at night. Manual receive is initiated by holding down button A in Timekeeping Mode for about two seconds. The stopwatch second hand indicates the reception status: R (READY) for setup, W (WORK) for in progress, Y (YES) for successful, and N (NO) for failed. The latest reception results can be viewed by pressing button A in Timekeeping Mode.
If the time and date settings are incorrect even after successful signal reception, the home positions of the hands can be adjusted. This involves holding down button A in Timekeeping Mode for about two seconds to enter adjustment mode, then using buttons B and D to align the second hand, hour and minute hands, 24-hour hand, day of the week hand, and date to their correct home positions.
In World Time Mode, button D is used to view the time in different cities. Holding down button A for about two seconds toggles the Daylight Saving Time setting for the displayed city. Swapping Home City and World Time City is achieved by holding down button B for about two seconds after selecting the desired World Time city.
The stopwatch can be started and stopped using button B in either Stopwatch Mode or Timekeeping Mode. Button D resets the stopwatch to all zeros.
To recover from the Power Saving sleep state, the watch can be moved to a well-lit area or any button can be pressed.
The watch's rechargeable battery does not require regular replacement. However, if the battery loses its ability to achieve a full charge after very long use, it should be replaced by a dealer or CASIO distributor. Users should never attempt to remove or replace the battery themselves.
When storing the watch for long periods, it should be kept in an area normally exposed to bright light to prevent the rechargeable battery from running down.
Certain charging conditions can cause the watch to become very hot, potentially leading to burn injury. Users should avoid leaving the watch in direct sunlight on a car dashboard, too close to an incandescent lamp, or under direct sunlight for extended periods.
The watch has an auto return feature, where if no operation is performed for about two or three minutes while a setting mode is selected, the watch will automatically exit that mode.
Scrolling through settings using buttons B and D supports high-speed movement when held down, which continues until any button is pressed or the moving hand(s) or day complete one full cycle.
In case of strong electrostatic charge, the time setting might be incorrect. Signal reception can also be affected by changes in the ionosphere, atmospheric conditions, weather, and seasonal changes. If signal reception is impossible, the watch maintains timekeeping within ±20 seconds a month at normal temperature.
If the stopwatch second hand points to N (NO) after reception, it could be due to manual time changes, button operations during auto receive, or an active stopwatch operation. The solution is to perform manual receive, stop stopwatch operations, or ensure the watch is in a good reception location. If the time setting is incorrect after reception, the Home City setting or hand home positions should be checked and adjusted.
General| Model Number | 4766 |
|---|---|
| Category | Watch |
| Type | Digital |
| Movement | Quartz |
| Alarm | Yes |
| Stopwatch | Yes |
| Calendar | Yes |
