4
reception is very limited during daylight hours. The forecast 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
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 forecast station has received the WWVB signal.
No tower icon is shown. The forecast station was unable to receive a signal at this time.
Reposition the forecast station for better signal reception or try again at bedtime.
The forecast 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
forecast 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 forecast station is not able to detect the WWVB-signal (disturbances, transmitting distance,
etc.); the time may be manually set.
WWVB Manual Signal Search
Normal mode:
Hold the
+
and
-
buttons together for 3 seconds to enter manual search.
Reception mode:
Hold the
+
and
-
buttons together for 3 seconds to exit searching for the WWVB signal.
Note
: In case the forecast station is not able to detect the WWVB-signal (disturbances, transmitting distance,
etc.); the time can be manually set by following the program menu.
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 forecast 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
Summary of Contents for 308-1451
Page 18: ...18 Appendix A ...
