Sloping down the capacitive loading wires you actually shorten the
antenna. If the loading wires are long and consistently sloped, you
mainly radiate with those wires instead of with the vertical section.
In the case you slope those wires down near to the ground, it's no
wonder the system efficiency drops because also the Rr becomes probably
very comparable with the unavoidable ohmic losses you have (basically
the ground resistance).
If needed, to better understand what I meant imagine the sloping hat as
a conical solid metal that sorrounds the vertical and whose circular
edge is quite close to ground.
Concerning the loading coil positioning, one has to be careful not to
exaggerate. Moving too off, the required inductance doesn't increase
linearly but exponentially and the losses of the required inductor will
increase. Beeing the coil in series with the antenna circuit if the
losses increase the current decreases.
Keeping in mind that with short verticals the current is almost
constant below the loading device, it's useless to have a longer
antenna portion below the loading coil if the total current is
consistently decreased by coil losses.
73,
Mauri I4JMY
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