"Wimpie" wrote in message
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On 12 abr, 00:47, "Yuri Blanarovich" wrote:
"Wimpie" wrote in message

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So if you suspended another dipole above your NVIS dipole and oriented
90
degrees to each other, the difference would be insignificant?
Then move it up into the "clouds", then move down to earth at the
distance
and you will see "insignificant" difference in signal levels?

Seems that direction finders should not work according to this
"verdict",
Eh?

One thing is the direction of the signals (maximum) another one is the
polarization. Based on the orientation of antennas, one can orient the
antenna to find the minimum signal.

Yuri, K3BU.us

Hi Yuri,

As the wave pass through the ionosphere, strange things happen. You
could google on Faraday rotation, ordinary and extraordinary waves to
find out that at low frequency, the change in polarization is
significant.

Change does not mean that polarization dissapears.

Based on the down coming wave, you cannot determine the orientation of
the transmitting antenna, neither the position with reasonable
accuracy (for NVIS propagation).

When you place the receiving antenna just above the transmitting
antenna you are right, but we were discussing NVIS propagation.

Best Regards,

Wim
PA3DJS

So when signal is reflected, the polarization disappears?

No, mostly the down comming wave has a circular component (eliptical
polarization), therefore the orientation is not of significant
importance. Wim, PA3DJS.

73 Yuri, K3BU


So if there is ANY polarization left how can you claim that is not of
significant importance.
The proof in the pudding is that on any signal one can with any antenna,
especially directional, find the spot where signal is minimal or nulled out.
Nulls are sharp vs. broad pattern, but one has to be aware of them and
understand the difference between the pattern and polarization.

Yuri, K3BU.us