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sketches are out of date before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.