this is reminds me of the TX antennas that have
been built for the 10 to 100 KHz bands.
In the very early days of point to point radio
using alexanderson gens and poulsen arcs the
antennas had to be highly subresonate even when
they were built between mountain tops as the upper
supports for the capacitance hat and the feed-point
and ground-plane lying in the valley below.
the antenna is a web/mesh of wires aproximating a
structure much like you describe... a funnel.
the lower section was cage-like. I believe
antennas of a similar approach are used in the
present day services such as LORAN and WWVB
for efficient launching of ground-wave propagation.
This 1000 to 2000 KHz variant may be a frequency scaled
version.
the feed point impedance is very high. the HIGH RF
voltages developed are remarkable and can be dangerous.
CU DE N2LO
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