Does Anyone Really Know What Time It Is?
If the band Chicago listened to WWV, they could have answered this question from their hit song. Tuning into 10 MHz, or any of their other five available frequencies, would produce a quick and accurate response. I can’t imagine why they didn’t try.
In the Beginning
After World War I, scientists and inventors were figuring out ways they could develop the potential of newly-available wireless communication. On October 1, 1919, the Bureau of Standards in Washington, D.C. established WWV as a new experimental station. A year later, the Bureau’s Radio Laboratory was broadcasting weekly Friday evening concerts from 8:30 to 11:00 pm on 600 kHz. WWV also began broadcasting 500-word Daily Radio Marketgrams, prepared by the U.S. Bureau of Markets.
At the end of 1922, WWV shifted to broadcasting frequency standard signals. This became an important aid to broadcasting and amateur stations because radio equipment of that era would sometimes drift from their assigned frequencies and needed an accurate standard for calibration. By May of 1923, WWV was broadcasting frequencies from 75 to 2,000 kHz on a weekly schedule. The accuracy of the transmitted frequency was quoted as being better than three-tenths of one percent.
In December 1932, the station moved to a Department of Agriculture site near Beltsville, Maryland. There were numerous changes in WWV’s broadcast schedule, format, and frequency. Also, the station underwent an upgrade with its transmitter becoming directly controlled by a quartz oscillator.
In 1966, WWV moved to its current location near Fort Collins, Colorado— about 50 miles from the Boulder Laboratories where the national standards of time and frequency were kept. The increased height above sea level and exceptionally high ground conductivity improved reception across the United States. Proximity to Boulder, Colorado, and the use of atomic oscillators at the transmitter site would make WWV even more accurate.
Time is on Our Side
WWV is the source of official U.S. time provided by the National Institute of Standards and Technology (NIST) and the United States Naval Observatory (USNO). They ensure that uniform time is maintained throughout the United States and around the world. WWV provides a public service by making time information freely available to anyone with a shortwave receiver.
How useful is WWV? The time signals generated by WWV allow time-keeping devices such as radio-controlled clocks and wristwatches to automatically maintain accurate time without manual adjustment. These time signals are used by commercial and institutional interests where accurate time is vital in daily operations, including shipping, transport, technology, research, education, military, public safety, and telecommunications. Think of WWV as the planet’s pacemaker.
Got an older tube-based transceiver? Without WWV to calibrate the dial on older ham rigs, you’d need to use a GPSDO (GPS disciplined oscillator) to locally generate a 10 MHz signal in the ham shack.
Even today, WWV and WWVH’s (WWVH is WWV’s sister station in Hawaii) standard time broadcasts and frequencies are a great help for engineers. While time-of-day information can be obtained through the internet, researchers say the combination of circuits involved in internet distribution can result in fraction-of-a-second delays that can affect pursuits such as high-speed trading. For accurate information without lag, terrestrial radio remains king, they say.
WWV/WWVH’s audio tones are also precise—and useful. On WWV, the 440 Hz tone (the A above middle C) is broadcast once each hour, during Minute 2 on WWV and Minute 1 on WWVH. Maestro, you could even tune your violins using WWV.
Propagation Observation
WWV’s signals travel from their transmitter site in Fort Collins to shortwave receivers, passing through the ionosphere and undergoing slight delays and frequency changes. These changes, when measured carefully, contain information on waves, density changes, and other phenomena forming space weather that could affect national telecommunications and power grids. Today, scientists are encouraged to know that even citizens using affordable, modest receivers in their backyards can participate in meaningful research. This concept is being realized now by the Ham Radio Science Citizen Initiative (HamSCI) in a project named GRAPE (Great Radio Amateur Propagation Experiment). Read much more about HamSCI on OnAllBands in October.
More Than Time
In 2019, WWV conducted communications exercises in coordination with the Department of Defense. Thirty-seven states, National Guard units, emergency management agencies, and others participated in simple announcements. They were meant to see how many listeners are out there and how far away they can be reached. The answer: there are thousands of listeners as far away as Australia and New Zealand.
With their high-power transmitters and multiple frequencies, WWV and WWVH could be useful for broadcasting emergency information from coast to coast. The quality of HF reception depends on many factors such as location, time of year, time of day, and propagation conditions. Given the variety of frequencies they use, it’s likely that at least one will be usable at any time.
NIST Would Be Missed
These benefits would come to an end should NIST’s time stations ever go dark. They almost did when they faced proposed budget cuts for 2019.
It’s not just WWV and WWVH that would be missed. If NIST station WWVB shuts down, self-setting clocks known as atomic clocks would no longer self-calibrate. There are more than 50 million radio-controlled clocks in operation and another few million wristwatches that rely on WWVB for self-calibration, in addition to weather stations, cameras, and other devices that may be affected.
These devices are so much a part our lives that we hardly notice them. Most of us assume they’re set by the Internet—but many aren’t.
