Sharp Atomic Clock Spc373 User Manual May 2026

Solution: Your DST setting is incorrect. Press and hold the ▲ button until DST "ON" or "OFF" flashes. For Spring/Fall, set to "ON" for automatic adjustment.

The Sharp SPC373 includes a green or blue LED backlight for nighttime viewing.

The SPC373 includes a built-in thermo-hygrometer sensor. Once batteries are inserted, it will automatically display: sharp atomic clock spc373 user manual

To toggle Celsius/Fahrenheit: Press the ▲ button once.

Note: If the temperature reads "HH.H" or "LL.L", the sensor is outside its operating range or damaged. Solution: Your DST setting is incorrect

Q: How often does the SPC373 sync with the atomic clock?
A: It attempts syncing at 12:00 AM, 1:00 AM, 2:00 AM, and 3:00 AM. It will also retry if the signal is weak.

Q: Can I disable the atomic sync and use only manual mode?
A: Yes. Set the clock manually, and it will not overwrite until you force a WWVB search. The SPC373 includes a built-in thermo-hygrometer sensor

Q: Does the clock work internationally?
A: The WWVB signal is only for North America (USA and parts of Canada). Outside this range, use manual mode.

Q: Why is my humidity reading higher than my other hygrometer?
A: The sensor takes time to stabilize after battery change (24 hours). Also, ensure the clock is not near a humidifier or bathroom.

Q: The snooze is too short. Can I change it?
A: No. The SPC373 snooze is fixed at 5 minutes.

If you live in an area without WWVB coverage (e.g., remote Alaska, deep valley), you can disable atomic sync and set time manually: