Once your radio controlled clock has synchronized, it won't decode the signal from WWVB again for a while. This means that the time in your area is corrected by the number of hours shown in the table. While a few users like their clocks to display UTC (ham radio operators, for example), most prefer to display local time. The time broadcast by WWVB is Coordinated Universal Time (UTC), or the time kept at the Prime Meridian that passes through Greenwich, England. Before it does so, it applies a time zone correction, based on the time zone setting that you supplied. Once your radio controlled clock has decoded the signal from WWVB, it will synchronize its own clock to the message received by radio. When you turn a radio controlled clock on, it will probably miss the first time code, so it usually takes more than one minute to set itself (sometimes 5 minutes or longer) depending on the signal quality and the receiver design.
#RADIA SHACK FULL#
They are sent at a very slow rate of 1 bit per second, and it takes a full minute to send a complete time code, or a message that tells the clock the current date and time. These bits are generated at WWVB by raising and lowering the power of the signal.
#RADIA SHACK SERIES#
Instead, all that is sent is a code, which consists of a series of binary digits, or bits, which have only two possible values (0 or 1).
Even that frequency is nearly 10 times higher than the WWVB signal.Īt 60 kHz, there isn't enough room on the signal (bandwidth) to carry a voice or any type of audio information. The lowest frequency received by any of the other radios in your house is probably 530 kHz, the bottom of the AM broadcast band.
#RADIA SHACK TV#
This is an appropriate name, because the FM radio and TV broadcasts that we are accustomed to listening to use frequencies thousands of times higher. The 60 kHz signal is located in a part of the radio spectrum called LF, which stands for low frequency. Your radio controlled clock actually has a miniature radio receiver inside, which is permanently tuned to receive the 60 kHz signal. WWVB broadcasts on a frequency of 60 kHz. In the United States, the signals received by radio controlled clocks originate from NIST Radio Station WWVB, which is located near Fort Collins, Colorado. A radio controlled clock has a radio inside, which receives a signal that comes from a place where an atomic clock is located. An atomic clock has an atomic oscillator inside (such as a cesium or rubidium oscillator). Some manufacturers refer to their radio controlled clocks as "atomic clocks", which isn't really true. This page provides information about radio controlled clocks, including how they work, where they work, and what to do when they don't work. During the transition from standard time to daylight saving time (DST) they "spring forward" one hour, and when DST is finished they "fall back" one hour.ĭue to technology advances and the economies of scale, radio controlled clocks are now very inexpensive, often costing just a few dollars more than conventional clocks. This means that you should never have to adjust them. They have a tremendous advantage over conventional clocks, they are always right! When working properly, radio controlled clocks always display the correct time, down to the exact second.
These clocks are sold in all forms: as wall clocks, desk clocks, travel alarms, and wristwatches. How They Workīy now, you have probably seen or own a radio controlled clock. You may also receive a printed copy by kathryn.stephenson (subject: Please%20send%20me%20a%20copy%20of%20SP960-14) (sending your mailing address) or by calling (303) 497-4343. WWVB Radio Controlled Clocks: Recommended Practices for Manufacturers and Consumers (NIST Special Publication 960-14, August 2009)
#RADIA SHACK PDF#
To find out more about WWVB radio controlled clocks, please download this 64-page PDF booklet:
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