Standard Time Stations as Radio Propagation Meters


Standard time stations, besides providing time synchronization and meterological information, aid radio hobbyists with a primitive gauge of radio propagation. Although ham radio and shortwave listening magazines and books (such as QST and WRTH) provide general propagation information, many times these sketches are out of date before hitting the stands. With a good ear and a steady hand, radio hobbyists can take the pulse of "openings" to different parts of the world and local frequencies. It's truly nifty to turn on my set at dusk or dawn and hear the various time stations roll in, announcing which programs I'll greet in the coming hours before I start my day.

I rely on time stations CHU and WWV/WWVB/WWVH for the bulk of my propagation information given my North American location. Given that CHU broadcasts from Ottawa, CHU's relative signal strength, as compared to its proximity, indicates little more than "first hop" short range propagation. CHU's location on isolated frequencies not shared with other time stations hinders its ability to contrast signal strength with other uniform signals.

More often, time stations are purposefully aligned on the same frequencies to create the cascading propagation effect designed to aid the listener in locating stations. The WWV, WWVH, and YVTO (Caracas) trifecta, when aligned well, exhibit fairly accurate propagational information to both the west and south of my location. Frequently WWVH pops up under WWV, during which WWVH's female voice announces the coming time a few seconds before WWV's male voice. WWVH's relative strength against WWV indicates the propagation activity towards the west and southwest. When combined with YVTO on 5000 kHz, the three stations' signal strenghts indicate western and southern directions.

I offer this example as the time signal propagation patterns most commonly experienced at my end of the wire, yet the technique can be applied to other time station configurations. Be mindful that the majority of time stations operate only during peak local times, or with power significantly less than WWV. Reduced operating hours are useful insofar as comparison of these less frequent signals suggests the best times to receive domestic shortwave broadcasts. I agree with Wiccanpiper that the decline of time stations (or reduction to longwave service only) detracts from time stations' myriad usages. Given that shortwave communications have declined to mostly hobbyist use over the past decade, I expect futher reductions in radio's jack-of-all-trades.