WWVB RADIO CONTROLLED TIME
The NIST radio station, WWVB, is located in Ft. Collins, Colorado and transmits the
exact time signal continuously throughout the United States at 60 kHz. The signal can be
received up to 2,000 miles away through the internal antenna in the Atomic Clock.
However, due to the nature of the Earth's Ionosphere, reception is very limited during
daylight hours. The Atomic Clock will search for a signal every night when reception is
best. The WWVB radio station derives its signal from the. NIST Atomic clock in
Boulder, Colorado. A team of atomic physicists continually measures every second of
every day to an accuracy of ten billionths of a second a day. These physicists have
created an international standard, measuring a second as 9,192,631,770 vibrations of a
Cesium 133 atom in a vacuum. This Atomic Clock regulates the WWVB transmitter.
Once the batteries are placed in the battery compartment, the WWVB tower icon in the
clock display will start flashing in the center of the LCD. This indicates that the clock has
detected a radio signal and is trying to receive it. When the time code is received, the
WWVB tower becomes static and a Wave OK icon will appear on the display.
If the tower icon flashes, but does not set the time and date, then please take note of the
following:
Recommended distance to any interfering sources like computer monitors or TV
sets is a minimum of 6 feet (2meters).
Within Ferro-concrete rooms (basements, superstructures), the received signal is
naturally weakened. In extreme cases, please place the unit close to a window
and! or point Its front or back towards the Fort Collins, Colorado, transmitter.
During nighttime, the atmospheric disturbances are usually less severe and
reception is possible in most cases. A single daily reception is adequate to keep
the accuracy deviation below 1 second.
Note:
In case the Atomic Alarm Clock is not able to detect the WWVB-signal (disturbances,
transmitting distance, etc.), the time can be manually set (please refer to notes on Manual
time setting).
