"Bob Bob" wrote in message
...
Someone asked me how this antenna worked after I had built the Q
section
from two pieces of 50r coax side by side, using the centre
conductors as
an open wire feeder equivalent. The shields being joined at each end
but
nowhere else.. (There should be grounded at the bottom end and at
some
neutral point at the top - if any)
The antenna is a almost equilateral triangular shaped single quad
loop
with base/feed about 4 metres off the ground. The "almost" being the
horizontal/top section is about 8 metres in length.
Well it works! I dont have enough of a power supply at the moment
for
doing any extensive on air tests. VSWR was 1.4:1 without much
excursion
at the band edges. This is what 4NEC2 said it would be. In fact I
didnt
have to cut it after following the modelled dimensions. It was
surprisingly wide band I guess from the higher feed Z (rather than
using
a single 75r section)
I have only just moved here and there is a lot of noise about at
various
times of the day. (S7-9) I have heard stations across the US and
maybe
some Spanish speaking. Waiting for a PSU to arrive so I can try a
little
harder.
I didnt notice any VSWR changes or a change in feedline radiation
(through PC/stereo spkrs etc) by coiling the coax at the base of the
Q
section. Indeed I did it because I was at risk getting tangled in
the
coax going to the trash can!
I expect high radiation angles BTW.
Cheers Bob W5/VK2YQA East Texas.
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Bob, what is the purpose of the coaxial outer conductors which are not
connected to anything.except to each other?
----
Reg.
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