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Atomic (radio controlled) clocks like the
B1854 Altus keep perfect time by calibrating themselves to 60kHz
low-frequency AM radio signals containing time information supplied by
the official U.S. atomic clock source in Boulder, Colorado. The radio
signals are transmitted from radio station WWVB, which is located in
nearby Fort Collins. Both the atomic clock source and WWVB are operated
by the National Institute of Standards and Technology, or NIST (a part
of the U.S. Commerce Department). The Altus clock initially searches for
the WWVB signal upon insertion of the battery and, after synchronizing
to the signal, searches several times per day thereafter.
The clock's quartz movement
has an integral radio receiver that detects the WWVB signal, and a
microchip adjusts the hands to display the exact time. With only a few
buttons to press, setup is really easy. To access the movement (and its
battery compartment), insert your thumb or finger in the hole in the
wood cover on the back of the clock, lift the cover straight up, and
swing the bottom of the cover out first. Then insert the included
battery and press the time zone button for your location (PT, MT, CT, or
ET). The second hand will advance 8 seconds in four 2-second increments
and then search for the WWVB signal. If the signal cannot be received,
the hands will advance to 4, 8, or 12 o'clock and search each hour until
the signal is received. Don't forget to replace the back cover.
This clock displays the
precise time in any location where the WWVB radio signal can be
received. This includes the continental U.S. (the "lower 48")
plus parts of Canada and Mexico. Daylight Saving Time adjustment takes
place automatically in the spring and fall, but if you live in Indiana
or Arizona, you can disable DST by pressing the DST-deactivate
pushbutton for 1 second. To reactivate the DST change, press the button
again for 1 second.
If you move to a different
continental U.S. time zone, you can adjust for it simply by pressing the
correct time zone button. Or, if you take the clock out of WWVB range or
use it in a location where the time signal cannot be received, you can
use the manual time set button to set the clock for local time, in
which case it will continue to operate as a highly accurate quartz
clock--but without the WWVB automatic time calibration.
The Altus atomic clock is
powered by a single AA (1.5 volt) battery, which is included and
normally lasts about 1 year. When the battery gets low, the clock tells
you this by advancing its second hand in 2-second increments. We
recommend using an alkaline battery when replacement becomes necessary.
Note 1: Included with this clock's
instructions is a brass-tone metal engraving plate with an adhesive
backing. If the clock is a special gift, you can have the plate engraved
with a name and notation of your choice. The plate fits in the recessed
vertical area on the front of the clock base in the center.
Note 2: The 60kHz AM
radio signal used by NIST to deliver the time information carries best
at night. The signal may be interfered with by weather conditions and
local interference. Building construction and location within a building can also affect reception. This clock is quartz
controlled and
will keep very good time for days when reception is poor, so this isn't
normally a problem. You may find, however, that when you first insert
the batteries, or during a Daylight Saving Time change, the clock will
not be able to set itself immediately if the signal is weak. As wiring and plumbing in your walls can affect reception, moving
the clock as little as a couple of inches can make a difference in the
strength of the signal reaching the clock. You can test a potential
clock location by tuning a portable AM radio to a weak station
(preferably one in the direction of Colorado) and placing it in the
proposed location. If the signal fades significantly, the location is
probably a poor one for an atomic clock.
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