Sharp Atomic Clock Spc373 User Manual May 2026

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.

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. sharp atomic clock spc373 user manual

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. Q: How often does the SPC373 sync with the atomic clock


Solution: Low battery. Replace immediately. Alkaline batteries only.

The Sharp SPC373 is a radio-controlled (atomic) mantel clock that automatically synchronizes time using the standard WWVB/NIST signal (North America) or similar longwave time signals where supported. This guide summarizes setup, daily use, features, maintenance, and troubleshooting so you can quickly get accurate timekeeping. Solution: Low battery

While the clock will set itself automatically, you must input your Time Zone and Daylight Saving Time preference manually.

  • DST (Daylight Saving Time): Set to ON (Auto) for most of US/Canada. Set to OFF for Arizona, Hawaii, or Saskatchewan.
  • Language for Day of Week: Select EN (English), FR (French), ES (Spanish).
  • Press SET to exit manual mode.
  • If you cannot receive the atomic signal (e.g., remote area, interference), set the time manually.

    Button reference (exact labels may vary slightly – typical for Sharp):