If the announcement states the time is 1830 UTC, eastern standard time would be 1330, or 1:30 p.m. An hour correction must be made to UTC to determine your local time.įor example, if you are in the eastern time zone, then subtract 5 hours from the UTC announcement during standard time and 4 hours during DST. The time announced on WWV and WWVH is Coordinated Universal Time or UTC, which is a 24-hour time system based at the prime meridian (0° longitude) located near Greenwich, England. How do I convert WWV or WWVH announcements to my local time? Normally, call signs that begin with a "W" are located east of the Mississippi River, but WWV, WWVB, and WWVH are exceptions, because WWV was originally located in Washington, DC. radio and TV stations begin with a "W" or a "K"). They are merely a unique combination of letters, just as for a commercial radio or TV station, that meet certain requirements as spelled out in the International Telecommunication Union's Radio Regulations (for example, call letters for U.S. Please visit the station web pages to read about the information transmitted by WWV and WWVH. WWV and WWVH broadcast much more than just the time. What other information is broadcast on WWV and WWVH? If you are using a cellular phone or a voice over Internet protocol (VOIP) connection, the delay can be much larger, but should still not exceed 150 milliseconds, based on International Telecommunication Union (ITU) recommendations for voice transmissions. Listening to the signals by telephone, the delays will be larger, but the time is usually accurate to within 30 milliseconds if you are using a landline. However, for most users in the United States, the received accuracy should be less than 10 milliseconds (1/100 of a second). This delay increases the further that you are from the station, and the delay can vary by as much as 1 millisecond if the signal is bouncing between Earth and the ionosphere. The time is kept to within less than 0.0001 milliseconds of Coordinated Universal Time (UTC) at the transmitter site, but the signal is delayed as it travels from the radio station to your location. When I listen to WWV or WWVH, how accurate is the time? The 5, 10 and 15 MHz transmissions are broadcast at a higher power than the other frequencies. The 5 and 10 MHz frequencies are probably the best signals to continually receive, and also the best signals to receive at night. The 15 and 20 MHz frequencies often work best during the daytime hours. In general, the 2.5 MHz signal works best for locations within a few hundred miles of the broadcast sites. Multiple frequencies are used because shortwave propagation varies with many factors, including time of year, time of day, geographical location, solar and geomagnetic activity, weather conditions and antenna type and configuration. General coverage shortwave receivers typically receive all frequencies from 530 kHz (the beginning of the AM broadcast band) to 30 MHz and are capable of receiving WWV and WWVH on all of the available frequencies. This part of the spectrum is commonly referred to as "shortwave". Both stations broadcast a timing signal 24 hours per day, 7 days per week, to listeners all over the world.Īll broadcast frequencies used by WWV and WWVH are in the high frequency (HF) radio spectrum which extends from 3 to 30 MHz. WWVH broadcasts on 2.5, 5, 10 and 15 MHz from Kauai, Hawaii. WWV broadcasts on 2.5, 5, 10, 15 and 20 MHz from a location near Fort Collins, Colorado. Why are both male and female voices used for the time announcements?.Is it possible to tour the WWV/WWVB facilities in Colorado or the WWVH facilities in Hawaii?. How do I convert WWV or WWVH announcements to my local time?.What other information is broadcast on WWV and WWVH?.When I listen to WWV or WWVH, how accurate is the time?.Descriptions and uses of radio signals from WWV, WWVB and WWVH.
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