Chaney Instrument 00581 User Manual

ATOMIC RADIO CONTROLLED

LCD DESK-TOP CLOCK

USER'S INSTRUCTION MANUAL

(USA VERSION)

1. What is Atomic Radio Control?
The most precise time keeping device on earth is the atomic clock. It keeps time to the accuracy of better
than 1 second for every million years. The atomic clock is a huge piece of scientific equipment and it is so
expensive that it is normally found in laboratories and standards institutions etc. Thanks to the latest
technology, the accuracy of the atomic clock is now brought to your home. The NIST* (National Institute
of Standards and Technology) is broadcasting electronically encoded time signals based on an atomic clock
from an antenna in Fort Collins, Colorado to cover the mainland of the United States. The signal is picked
up by the radio receiver circuit in your clock, and is then decoded to synchronize the time to within a split
of a second precision. The radio signal automatically sets the calendar and daylight savings or standard
time too.

Fig. 1 Atomic radio controlled time signal transmission and reception

* For more information on the NIST transmission and cesium atomic clock visit www.bldrdoc.gov/timefreq

Note: The clock is used in USA mainland only. In the states of Alaska and Hawaii, the radio signal may not
be strong enough for synchronization and the clock can only be used as a normal quartz clock that needs
manual setting.

2. About your Clock

3. Battery Type
The clock uses 2 AA size batteries, alkaline type is recommended. Insert batteries observing the polarities
shown in battery compartment or remove insulating tag if the clock comes with batteries. (The clock is
designed to maximize battery life. The trade off for this is that with brand new batteries, some shadowy
effect appears on the LCD. This effect will last only for a few days.)

4. Auto-synchronization
After inserting batteries, set the clock to the correct time zone. This is done by sliding the Mode Switch to
ZONE / DST position as shown in Fig. 4 and then push the ZONE button to select the right time zone
(Pacific, Mount. - for Mountain, Central or Eastern) depending on where you are located.

Once batteries are installed, the receiver circuit is activated. This is symbolized by the blinking of the
Antenna icon (See Fig. 5a). The Bars facing the Antenna indicate the strength of the radio signal, no bar
means there is no or very weak signal received, one bar indicates a weak signal and 5 bars the strongest

(see Fig. 5b). Use the radio signal strength indicators to find a location that the reception is strong. If the
clock is too close to electrical appliances such as TV, mobile phone and computer they may cause
undesirable signal interference. Strong signal is normally found close to the window. In some areas where
the signal is poor or less, you may need to position and rotate the clock until the best signal strength is
obtained. When the signal strength falls to 2 bars, remove the antenna from the back of clock (Fig. 3) and
move the antenna around if necessary but the antenna needs to be kept horizontal for the best reception.

Once you have found the optimal position leave the clock still so that it can pick up good signals. It
normally takes 3 to 9 minutes to synchronize. Once it is successful, the clock will show extremely accurate
time and the correct date. Successful synchronization is symbolized by the still antenna and the radiating
beacon. (Fig.7)

A properly synchronized clock attempts to adjust itself with the radio time signal every evening and if it
fails for more than 24 hours, the Antenna icon disappears. The clock will still function as a quartz clock
until it gets synchronized again.