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Multi-Band 6 Explained: How Atomic G-SHOCKs Set Themselves in the U.S.
Short answer
Multi-Band 6 G-SHOCKs set themselves from radio time signals broadcast by six stations, including NIST's WWVB near Fort Collins, Colorado, which transmits at 60 kHz. Casio puts the U.S. signal's reception range at about 3,000 km, which covers most of the continental United States.
What is Multi-Band 6?
Multi-Band 6 is Casio's radio-controlled timekeeping: the watch receives time signals from six transmitters, two in Japan and one each in China, the United States, the United Kingdom and Germany, and corrects itself automatically. People often call these watches atomic, because the transmitters are tied to atomic clocks.
Will an atomic G-SHOCK work where I live?
In the U.S., the signal comes from NIST radio station WWVB near Fort Collins, Colorado, on 60 kHz. Casio's manuals put its reception range at about 3,000 km under good conditions, so most of the continental U.S. is covered; buildings, mountains and electrical noise can weaken it.
- Sync at night, when reception is usually best.
- Leave the watch near a window, away from TVs, computers and metal surfaces.
- If it fails, try again the next night; the watch also retries automatically.
Multi-Band 6 vs Bluetooth time sync
Multi-Band 6 needs no phone, only a radio signal. Bluetooth models such as the GA-B2100 get the time from the CASIO WATCHES app instead, which works anywhere your phone has the time. The GMW-B5000 has both.
Which G-SHOCKs have Multi-Band 6?
Of the models we cover, the GW-6900, GW-M5610 and GMW-B5000 have Multi-Band 6. The GA-2100, GM-2100, GA-700, DW-5600, GA-V01 and G-7900 are standard quartz watches you set by hand.
| Model | Display | Tough Solar | Multi-Band 6 | Bluetooth | Power |
|---|---|---|---|---|---|
| GA-2100 | Analog-digital | No | No | No | 3-year battery |
| GA-B2100 | Analog-digital | Yes | No | Yes | Solar, ~7 mo per charge |
| GM-2100 | Analog-digital | No | No | No | 3-year battery |
| GW-6900 | Digital | Yes | Yes | No | Solar, ~9 mo per charge |
| GA-700 | Analog-digital | No | No | No | 5-year battery |
| DW-5600 | Digital | No | No | No | 2-year battery |
| GW-M5610 | Digital | Yes | Yes | No | Solar, ~10 mo per charge |
| GMW-B5000 | Digital | Yes | Yes | Yes | Tough Solar |
| GA-V01 | Analog-digital | No | No | No | 10-year battery |
| G-7900 | Digital | No | No | No | 2-year battery |
FAQ
Do atomic G-SHOCKs adjust for daylight saving time?
The time signal carries the current time, so a synced watch shows the correct local time once its home city is set; check your module's manual for the daylight saving setting.
Does the GA-B2100 have Multi-Band 6?
No. The GA-B2100 syncs time over Bluetooth with the CASIO WATCHES app rather than by radio.