See this 1961 IRE paper at the NIST website: https://tf.nist.gov/general/pdf/2303.pdf IRE merged with AIEE in 1963 to form IEEE.
Figure 7 shows the calculated amplitude transfer of the ground wave signal vs frequency and distance. Note that for 100 kHz signals, the ground wave signal is reasonably strong at 2,000 miles but lousy at 5,000 miles. As this paper notes, the sky wave reflections are delayed, and this delay depends on the ionization state of the ionosphere along the propagation path. This delay is shown in figure 2. Figure 6 shows differences between daytime and nighttime propagation of pulsed signals. The received signal is a combination of the ground wave signal and one or more skywave signals (which are delayed with respect to the ground wave signal). -- Bill Byrom N5BB On Fri, Aug 7, 2020, at 5:16 PM, Gilles Clement wrote: > Would’nt 100khz carrier propagate mostly by ground wave (during day time) ? > So following earth curvature ? > Gilles. > > > > Le 7 août 2020 à 21:34, paul swed <paulsw...@gmail.com> a écrit : > > > > Taka > > Yes it does. More ionosphere than air. It would be skywave or indirect > > path. I mentioned that earlier. > > Now silly thought would a huge antenna work especially if you are at the > > antipode. Further would it be gray line propagation. > > Thats just silly talk. But something to think about. > > Regards > > Paul. > > > >> On Fri, Aug 7, 2020 at 2:01 PM Taka Kamiya via time-nuts < > >> time-nuts@lists.febo.com> wrote: > >> > >> Wouldn't such a long distance propagation result in less precision? The > >> signal will have to go through distance through air which isn't constant in > >> dialectic values. Wouldn't it be problematic for level of accuracy we > >> pursue? > >> > >> --------------------------------------- > >> (Mr.) Taka Kamiya > >> KB4EMF / ex JF2DKG _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
