This document provides the operation guide for CASIO watch, including charging, battery usage, power saving function, etc.
This manual explains how to operate the Casio 2608, 2638 and 2688 radio‑controlled watches. It covers basic functions such as timekeeping, world time, alarms, stopwatch, time recorder, and the solar‑charged battery system. Detailed instructions are provided for setting the Home City, using the backlight, and configuring the auto‑light switch.
The guide also describes how the watches receive the atomic time‑calibration signal from the Fort Collins transmitter, including auto‑receive schedules, manual receive procedures, troubleshooting tips, and the limits of signal reception (up to about 2,000 mi). Safety and battery‑replacement information are included to help keep the watch running reliably.