Hello Stefan, and thanks for interesting reply.
But a few more comments before I go back to lurking. As yet I am not signed
up to lurk also on the yahoo reflector. Perhaps I will when a bit less busy
and if persuaded of the benefits of doing so.
I want to try to get a antenna orientation beaming to G and PA, where the
most RX stations are present
My point is that you might have to orientate the antenna at right angles to
what is normally expected if the loop mode is stronger than the dipole mode.
It indeed may depend on ground conductivity?
I will also try different heights above ground, starting from 0 to maybe
2m or 5m AGL.
This will be very interesting. Over dry ground on 160m amd 80m I have
found that differences with similar height differences to these are quite
small, less than 6dB or so. It is not until you approach the critical
height that the height gain becomes very significant.
Occasionally broadcast signals in the 31m and 25m bands were found to be
be stronger on the underground antenna than on the reference antenna.
A stronger S/N or a stronger signal level?
The signals were definitely stronger but the noise level was usually a bit
higher, perhaps by 6 to 10dB.
BTW it is not at all easy to evaluate the differences of such different
antenna arrangements. I have never seen such a QSB on any band. Probably
it is the best to have a local RX station and do the tests on groundwave
distance. Probably the antenna radiates in a very high angle But the
difference (of the simulation) between 90 deg and 20 deg is just 5 dB
while the antenna gain is stated to be -5 dBi..
Good points. But it is measurements that confirm the veracity of simulations
and never the other way round.
Looking forward to seeing your results. And now back to lurking!
73 - Mike - G3LHZ
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