La Crosse Technology Wireless Color Weather Station 308-145B - Manual (Page 5)

5
WWVB RADIO CONTROLLED TIME
The NIST radio station, WWVB, is located in Ft. Collins, 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 Weather Station.
However, due to the nature of the Earth’s Ionosphere, reception
is very limited during daylight hours. The Weather Station 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.
WWVB RECEPTION ICON with full signal strength will appear on screen in front of the date
when the reception of time is successful.
The tower icon will show solid when the Weather Station has received the WWVB signal.
No tower icon is shown. The Weather Station was unable to receive a signal at this time.
Reposition the Weather Station for better signal reception or try again at bedtime.
The Weather Station will start searching at UTC: 07:00 and if no reception on the first attempt they
will try again at 08:00, 09:00 and 10:00. Each attempt will be at least 2 minutes and the most will be
10 minutes.
If there is no signal or too much interference the receiver will only be on for 2 minutes.
If the signal is good it may catch a signal in ABOUT 2-3 minutes.
If the signal is marginal it will try to catch a signal for up to 10 minutes.
IMPORTANT: When operating on a/c power, the backlight and USB charge port will turn off while the
Weather Station searches for the WWVB signal, to avoid interference. Both features will return after
the 2-10 minute search which occurs during the late night or early morning hours.
Note: In case the Weather Station is not able to detect the WWVB-signal (disturbances, transmitting
distance, etc.); the time may be manually set.
Manual Signal Search: In normal mode, hold the RCC button until the reception icon appears to force a
search of the WWVB signal. The WWVB icon will flash during the search. If this icon disappears after
the 2-minute search, the radio time signal is not available at the moment.
Recommended distance to any interfering sources like computer monitors or TV sets is a minimum of
6 feet (2 meters).
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 Weather Station is not able to detect the WWVB-signal (disturbances, transmitting
distance, etc.), the time and date can be manually set (
see “program menu”).
FUNCTION BUTTONS: