Hi Peter, The delay you describe is rare, but could be possible occasionally. Radio signals propagate by bouncing and bending thru various mediums, like the Ionosphere, Troposphere, Magnetosphere and so on. Typically the propagation time delays are quite small for 'terrestrial' signals. The frequencies you mention are for CHU (3.333) the Canadian time station and WWV and possibly WWVH (in Hawaii) the US time stations. WWVH is distinguishable by it's female announcing voice. Most of the time the HF propagation delay from the transmitter to the listener is in microseconds (25 - 175), and as such ignorable. Even a multi hop or long-path propagation effect of circumnavigating the globe is a mere 138 milliseconds. Longer delays of up to 300 milliseconds have been reported via Magnetosphere ducting of paths longer than 1 earth radius. What you describe could have been an LDE or Long-delayed echo, which have been reported during sunspot minimums. In these events multiple echoes have been heard lasting up to 7 seconds or more, but these events are very rare an still not well understood. Therefore the use of radio/HF time signals should not be considered an accurate method of timing derivation. Regards, Walter Ridgewell, I.S.P ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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