MODEL: WT-941
WWVB—RADIO CONTROLLED WATCH
ABOUT WWVB (Radio Controlled Time)
The NIST (National Institute of Standards and Technology—Time and Frequency
Division) WWVB radio station is located in Ft. Collins, Colorado, and transmits the
exact time signal continuously at 60 kHz. The signal can be received up to 2,000
miles away through the internal antenna in the watch. However, due to the nature of
the Earth’s Ionosphere, reception is very limited during daylight hours. The Watch
will search for a signal every night when reception is best. The WWVB radio station
derives its signal from the NIST Atomic clock in Ft. Collins, Colorado. A team of
atomic physicists is continually measuring every second, of every day, to an accuracy
of ten billionths of a second per 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 watch is regulated by the WWVB transmitter.
SET-UP GUIDE, FEATURES, AND OPERATION
I.
ACTIVATION
The Radio-Controlled watch is programmed and shipped in a battery-saving
mode. The LCD (Liquid Crystal Display) displays “OFF” and must be
activated before set-up can begin. Your watch may not be in this mode; if not
all you need to do is set your time zone (the correct time may or not be
shown).
1. Press the TIME ZONE button briefly to activate the WWVB reception
search. The LCD lights up briefly and will then display “-:--” and the
watch will begin to search for the WWVB signal. If a signal is found,
a “tower” icon will flash; if no signal is present, no icon will flash.
2. Within six minutes, the watch will either set to the exact time and
date (Eastern is the default), or will display “-:--”.
Do not press the TIME ZONE button while the watch is searching for the
WWVB signal, which normally takes 6-10 minutes. However, the optimal
time for WWVB reception is between midnight and 6:00 a.m., reception may
not occur until this time period. When the WWVB search is complete the
time and date will automatically be displayed in the LCD. If the watch is not
within range of WWVB signals for an extended period of time it will still
continue to operate as a highly accurate quartz controlled clock.
II.
TIME ZONE SELECTION
The default Time Zone is Eastern Time (EST, also GMT-5). There are 25
Time Zones to choose from. The selection will cycle from GMT-5 to GMT-
12, then GMT+12 to GMT +1, then GMT, then GMT-1 to GMT –5.
1. Hold down the TIME ZONE button for 2 seconds, or until a Time
Zone abbreviation and “ZONE” flash in the LCD, and release.
2. Repeatedly press the TIME ZONE button until the appropriate Time
Zone is displayed.
3. Wait 6 seconds for the automatic time-out to exit the Time Zone
selection mode.
III.
DAYLIGHT SAVING TIME (DST)
Through the WWVB signals, the watch automatically adjusts for Daylight
Saving Time.
IV.
SHUTDOWN AND RESETTING
This procedure will clear all information. Follow the above sections (I, II) to
activate the watch again.
1. Hold down the TIME ZONE button for 6 seconds. The LCD will
cycle from normal display, to Time Zone display, and back to normal
display. The final display will be “OFF.”
V.
MANUALLY ACTIVATING THE WWVB SEARCH
At any time after the Time Zone has been selected, and during the normal
operating mode:
1. Hold down the TIME ZONE button for 4 seconds (the LCD will
display the time zone then will revert back to normal view). The
WWVB tower icon will appear in the upper right corner of the LCD,
indicating that the watch is searching for a WWVB signal.
Note: It is important not to hold the TIME ZONE button down long
enough to shutdown or reset the watch.
VI.
LOW BATTERY INDICATOR
The watch is supplied with, and powered by a high quality 3V lithium battery
with a life expectancy of over 2 years. There is a low-battery indicator that
appears between the minutes and the date when the battery is low. The
battery should be replaced within 2 months of the appearance of the low-
battery indicator.
VII.
MAINTENANCE AND CARE
Under normal conditions, the watch is shock resistant, however avoid
excessive “rough” treatment of the watch as this may cause serious damage.
Clean the watch with a soft dry cloth, or with one moistened with a mild soap
solution. Do not use any chemical cleaning solutions, these may cause
permanent damage to the watch’s surface. While the watch is water resistant
TIME ZONE key
“Hawaii Time displayed
(GMT-10)
Atlantic Time (ATL): GMT-4 Alaska Time (ALA): GMT-9
Eastern Time (EST): GMT-5 Hawaii Time (HAW): GMT-10
Central Time (CST): GMT-6
Mountain Time (MST): GMT-7
Pacific Time (PST): GMT-8 Greenwich Mean Time (GMT): GMT
