On 14 Jun, 12:43, art wrote:
On 14 Jun, 11:47, "Yuri Blanarovich" wrote:





"Richard Harrison" wrote in message

...

Kraus writes on page 252 of

his 1950 edition of "Antennas":
"If an emf is applied at the terminals of an antenna A and the current
measured at the terminals of another antenna B, then an equal current
(in both amplitude and phase) will be obtained at the terminals of
antenna A if the same emf is applied to the terminals of antenna B, It
is assumed that the emfs are of the same frequency and that the medium
is linear, passive, and also isotropic."

That is fine and guaranteed in ideal cases or when antennas "see" each
other. But when signals are going through the ionosphere and considerable
distances, things don't jive exactly like that. I had cases when at
particular opening I would receive say OK2 at the lower angle and UA0 at
higher angle, which is not "normal" but on transmit the situation would be
just opposite, indicating that ionosphere (ether :-) would be behaving
differently at the ends of the paths. This definitely was not the result of
the local noise masking signals "explaining" disparity.
Again, I summarized my finding in my article in CQ. I came to the conclusion
that about 60% of propagating is not reciprocal RX vs. TX. That was done
using my stacked Razor antennas. Believe it or not, but that is like person
with reading glasses (dipole) will not see what person with telescope
(Razors) can see.

73 Yuri,www.K3BU.us

I can go along with that! As the different layers form, rise and form
at
different rates with the sunrise and sunset it is difficult to lean on
the idea that
all radiation is reciprocal. If one sees the return curve of radiation
formed as a
layer is met it is also difficult to understand how the layer
is consistent in density, shape and altitude. When wind shear was
mentioned it reminded me
of the situation where skin depth on the ocean surface varies with
climatic conditions
when dealing with VLF. Why would a ducting signal pierce a layer at
one point and
continue to skip at other points if layer density was constant? True,
one can feel confident
of reprocity if communication is ongoing which is all they care
about.
But if one thinks of the possibilites why a CQ does not meet with a
responce
as a means of determine the validy of one way
propagation............!!!
Art- Hide quoted text -

- Show quoted text -

Another thought. When using NEC style programs on antennas we see a
common TOA
regardles of the mix of polarization. We do know that common
polarisation
can be created on reflection from the ionisphere but I believe the
trajectory
of radiation changes depending on the influence and density of the
terrain
on the polarization when transmitting. If this were to be correct we
could
well be examining two or more separate trajectories that could dispel
the idea
of reprocity. Remember that North /South lines of electromagnetism
assist
such that it can be noticed in communications so its implications
cannot
be ruled out with respect to one way propagation.
Fortunately new books are regularly printed as science moves on where
old books and ideas printed in them finish up in the ground with the
generation that coveted them.
Art