Thank you to every contributors, you have helped me to take the decision : I
will install soon a low dipole.
Every contributor have ever verified that there are circumstances (rarely for
some and frequently for others, perhaps the geographic position) when the low
dipole is better than a vertical. Furthermore, some have even experimented dx
contacts impossible otherwise.
It seems that it can happen not only during sunset / sunrise but also during
geomagnetic storms (high K index).
Majority is confirming that what is involved in the low dipole is its high
angle lobe which permits to transmit/receive signals that the vertical/beverage
cannot. One contributor seems to think that polarization could have a role.
Heigh of the dipole does not seem critical and is usually between 30 and 120
feet (even if 120 feet is pretty high for most of us, it is low for the 160m).
If I suppose that high angle is the main reason, I can use any orientation for
the dipole (because it has no directivity at high angles) and choose the one
which minimize the local ground wave qrm (keeping in mind that the groundwave
directivity of a dipole is 90 degrees of its skywave directivity : the maximum
groundwave reception is to the antenna ends and minimum is broadside)
73, Gilles / VE2TZT
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