Dear Walter, LF Group,
Very interesting to hear about the "million-to-one" 9kHz <=> 10GHz
cross-band QSO.
As a rough rule, most of the antenna books use the distance
lambda/2pi as the boundary between near field and far field of an
antenna, although many other factors are involved. With about
33km wavelength, this puts the boundary at about 5.3km, so as Rik
points out, some form of near-field coupling mode is probably
involved - perhaps the mutual capacitance between antennas
would be a good way of looking at it.
It would be very interesting to see how results compared if a
magnetic RX antenna was used, ie. ferrite rod or loop. I can see
this will be a fertile ground for theories!
Cheers, Jim Moritz
73 de M0BMU
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