![]() ![]() The stations were on the air prior to the first commercial radio station KDKA in Pittsburg. Since 1919 the WWV radio stations have served as a platform for research on radio communications, standard frequencies, and standard time. To read the fascinating history of the importance of time, for navigation, read Longitude by Dava Sobel.) In the United States, standard time originates at an atomic clock and is disseminated by the National Institute of Standards and Technology (NIST). The standards include weights, distances, frequency, and time. The monitoring sites are scheduled to supply new data to NIST every 10 minutes.Governments throughout the world maintain and disseminate a variety of standards needed for scientific research, navigation, commerce, radio and television broadcasting, and daily living in general. The date and time (UTC) when the information in this row of the table was last updated. If you cannot get your RCC to work during the daytime hours, it will still probably synchronize if you let it run overnight. Most products only attempt to synchronize at night when the readability conditions are generally Excellent or Very Good in most parts of the continental United States. 1 - Unreadable - It is highly unlikely that a RCC will be able to synchronize right now, but conditions should improve later.2 - Intermittent - The conditions are not optimal, but a well designed RCC should still be able to synchronize.3 - Very Good - Most RCCs will be able to synchronize under these conditions.4 - Excellent - Nearly all properly functioning RCCs should be able to synchronize under these conditions.The current signal readability rating can have one of four different values: Keep in mind that these ratings only apply if your RCC is located in the same region of the country as the signal strength meter. The readability rating displayed in this column was designed to estimate whether or not a RCC will be able to synchronize. Keep in mind that not all RCCs are created equal, some employ advanced digital signal processing techniques that will allow them to synchronize under conditions where other products will fail. In order for a RCC to synchronize, it has to be able to successfully read and decode time code bits for at least a full minute, and many products require at least two complete time codes to be read before they display the received time.įluctuations in the signal strength, even if the signal is strong, might make it impossible for a RCC to successfully decode the time. A complete time code contains 60 bits of information and requires a full minute to be sent. The WWVB time code is sent at the very slow rate of 1 bit per second. A radio controlled clock located indoors at the same location will receive less signal and may be subjected to more interference. The receiving antennas are located indoors or outdoors (as noted) and pointed towards WWVB. The city and state where the signal strength meter is located. The current readability of the WWVB time code is updated in the table below every 10 minutes. ![]() These sites to determine the current signal conditions for radio controlled clocks (RCCs). The WWVB signal is continuously decoded at each of The map below shows the location of the WWVB time code monitoring sites. The Current Readability of the WWVB Time Code ![]()
0 Comments
Leave a Reply. |