In many any high-tech stores, “Radio Controlled” watches or clocks are available. These clocks have the mechanism to synchronize themselves with the atomic clock in Boulder, Colorado. These types of Atomic clocks are available in all types of watches; wall and desk clocks, wristwatches and travel alarm clocks. They are extremely accurate as compared to the conventional clocks or watch; they are the most accurate timekeepers around the world.

These types of radio controlled watch always display precise time; they keep the time even within a fraction of second. These types of radio-controlled watches don’t need  manual adjustment. These watches automatically “spring forward” one hour when the time switches to daylight time-saving; and when the DST gets over, the watch “fall back” an hour automatically.

How Atomic Clock Works

A radio controlled watch has a cesium and/or rubidium installed inside it; it also has an inbuilt radio installed the clock that catches the signal from atomic clock. It then synchronizes with the time of atomic clock. In US, such signals are received via NIST Radio Station WWVB, Colorado at 60 kHz frequency. In ‘Low Frequency’, 60 kHz is positioned at radio spectrum. The name “Low Frequency” is an extremely suitable since radio FM and TV broadcasting that we use everyday are about thousand times higher than LF. The minimal frequency receives by radio is most likely 530 kHz, Which is ten times higher as compared to WWVB signal of Low Frequency.

The bandwidth at 60 kHz is extremely low, thus leaving no space to transmit a sound or audio information. All the data in such an atomic clock are sent in a code that comprises of a string of Binary Numbers or Bits that consists only of two rates (0 / 1). Binary Digits accelerated at WWVB done by increasing and decreasing the signal strength. They are passed at an extremely gradual tempo of one bit per sec, and it requires a minute to drive an entire time cipher or a massage that informs the watch the present date & time. The moment you start a Radio Controlled Watch it many a times ignore the initial code. Therefore, taking about one minute or more to set itself; or rely on the strength of the signal and the design of the receiver.

Once the Radio Controlled Watch decipher the indication from WWVB, then it will automatically synchronize with the signal communication gathered by the radio. Prior to it, the watch applies an adjustment for time zone, build on time zone you have selected. The WWVB transmitter broadcasts the Coordinated Universal Time (UTC) date & time, or Prime Meridian Greenwich Time, England. The time can be fixed by the adding the number of hours indicated in the below table.

The time can be fixed by the adding the no. of hours(71267)

Initially when the Radio Controlled Watch of yours synchronizes with WWVB then it won’t decode again immediately. Few of the watches decode the message only once in a day, and other decode every 4 or 6 hrs. The clocks, which are mechanized to decode only once, is programmed to do it during the night, since the signal from WWVB is quite stronger during night compared to daytime. The Quartz Crystal Oscillators keeps the clock on time, between the synchronization phases.