Suggest it's this thing called antipodal convergence.
mentions under convergence for VLF but IIRC I read something
about it for HF as well.
Idea is one of all the radio waves converging, regardless of path,
at some point, on the other side of the propagation time, globe.
The radio antipode is not necessarily the geographic antipode
because of the way the propagation paths work out to follow
the best ionization path for the particular frequency your using.
The familiar 'grey-line' propagation is a good example of this.
I've experienced in working North Africa and Southern Europe from
teh South Pacific on 80 and 160.
Jim Reid wrote:
> A bit disappointed with present propagation, solar flux this
> morning is at 103! Not real great. Only 20 meters stuff I
> could hear out here was from Californina(weakly), JA, ZL,
> Hong Kong and South Africa (?); not sure why ZS is heard hear
> while everything else is around the Pacific rim. Hearing the Pacific
> rim is not surprising here given where Kauai is, hi.