What is the ideal system for precise timekeeping?
Capturing a time signal from an atomic clock accurate to 1 second every 100,000 years,
iRadio-Controlled auto-corrects the time and calendar in your watch.
Combined with CITIZEN's light-powered Eco-Drive technology,
the result is ultraprecise timekeeping
with no need to replace batteries or adjust the time.
In 1993, CITIZEN released the world's first multi-band radio-controlled watch.
As a pioneer, we continue to lead the field.
3... 2... 1... Happy New Year! With a Radio-Controlled watch, you can be sure that your personal New Year countdown will be bang on time. The atomic clocks from which Radio-Controlled watches receive their time signals are accurate to an astonishing margin of one second every 100,000 years. By synchronising with the most accurate time source in existence, your watch will always tell you the precise time.
Adjusting your watch is a bore. Radio-Controlled does away with all that anxiety and fuss. In the middle of the night when the noise from smartphones is at a minimum, it automatically synchronises to the correct time. Radio-Controlled, in other words, fine-tunes itself every day of the week so that you don't need to worry about resetting your watch anymore. Ever.
This technology automatically updates the time and date based on a time signal from an atomic clock with a margin of error of one second every 100,000 years. In Japan, it receives signals from the Mount Otakadoya Standard Time Transmitter in Fukushima and the Mount Hagane Standard Time Transmitter in Kyushu, meaning that it covers the whole country.
Radio-Controlled operates based on the reception of a time signal from transmitters in four different regions: Europe, the United States, China, and Japan.
* Applies to world multiband models.
* Map is a rough illustration only.
* Concentric circles indicating time signals on the map are purely for illustrative purposes and do not indicate actual ranges.
* Different models have different coverage
* Reception can be affected by radio noise, local topography, buildings and weather.
* Time differences and city names may change depending on the country/territory.
CITIZEN has developed a proprietary technology that makes precise timekeeping possible by combining three functions: an antimagnetic function, an impact detection function and an automatic hand correction function.
'Genuinely precise timekeeping' was an unobtainable goal that still lay beyond the grasp of the watchmaking community when in 1989 CITIZEN decided to develop a watch that would display precise time based upon the reception of radio waves. CITIZEN had no background in this field, meaning that there was a veritable mountain of technological challenges we had to overcome. Lacking the proper equipment, we had, for example, to rig up an antenna close to the window of the R&D laboratory and build our own devices to measure receiver sensitivity. We even developed our own integrated circuit compatible with time signals (not available in Japan at the time), and grappled with how to miniaturise the antenna.
It was after overcoming many technological challenges that in 1993 CITIZEN launched the world's first multiband radio-controlled watch. Signal reception sensitivity depends upon the antenna but is prone to interference from the metal watchcase and other metal parts. That's why we went for a bold, counterintuitive look with the antenna right in the centre of the dial. 'Look at me! I'm a radio-controlled watch!' the design proclaimed.
In 1996, CITIZEN developed the world's first Radio-Controlled model incorporating Eco-Drive. We placed the antenna on the 9 o'clock side of the case, improving both reception and design. The addition of light-powered technology and automatic signal reception eliminated the hassle of adjusting the time and replacing batteries.
Radio-Controlled had evolved to the stage where the design no longer stressed the
Having producing a model with the antenna on the side, in 2001 we produced a model with the antenna built into a ceramic case and an Eco-Drive model with reduced power consumption. By improving the antenna and the receiving circuit we dramatically boosted reception sensitivity, meaning that in 2003, we were able to produce the world's first radio-controlled watch with a full metal case—something until then believed to be impossible.
Following the introduction of the Eco-Drive Radio-Controlled model with full metal case in
2003, Radio-Controlled established itself as one of CITIZEN's core technologies. In a quest for smaller,
thinner, more elegant, and more varied watch designs, we further miniaturised the antenna and made the
movement smaller by reducing energy consumption.
The picture below shows 15 years' worth of antennas from 1993 to 2008. You can see that the antenna grew significantly smaller over time. The challenge, however, goes on. CITIZEN's quest for the perfect form never ends.
* Some featured models are no longer in production or are unavailable in some markets.