Hi Mike,
Funny you should ask that.
A few months ago (September) I was looking at building a smaller size DHDL
using 4Nec2, and there were a few things I saw that I thought needed
improvement (I saw things in the full size DHDL that I thought needed
improvement, it was not limited to the small size DHDL I was trying to
design). Then I started to play around with the location of its
termination resistor as well as routing of wires, and wound up with what I
called the Terminated Bowtie. I built one in my backyard but my yard is
pretty small and the antenna was too close to existing objects (house and
chain link fence) and I did not realize the S/N improvement that I
expected, nevertheless based on modeling it looks like a winner (9.5 RDF
and front to back ratio versus elevation angle very robust).
I have attached the preliminary document I put together a few months ago
for you and others to view (it might not be perfect, but should convey my
design / thoughts). I would love someone to build one of these out in the
open to see if the real life build provides results similar to the 4Nec2
modelling I did.
Note: Bringing the feedline away from the antenna properly needs to be
looked at to minimize distortion of the pattern. As I recall the feedline
should not drop down to the ground until it's at least 5 feet away from the
antenna, and a greater distance would be best. The feedline should also
use choke with ground rod similar to what's recommend for other RX antennas
we use (beverages, flags, etc.) to block common mode noise from making its
way to the antenna feedpoint.
Let me know what you think. It might not work, but sure looked good on
paper.
73,
Don (wd8dsb)
On Sun, Dec 11, 2016 at 9:41 AM, D Michael <damichael@verizon.net> wrote:
>
>
> I have two flag rx ants and I was looking at the DHDL and DK6ED Double
> Loop System V2 and wondering if twisting my Flag rx ants into Bowties
> would improve the forward pattern and make them narrower with better front
> to back.
> I would just ""flip"" the termination resistor end to form a loose BOWTIE
> shape.
> I have no ant modeling software so I have no way to ponder this change.
> Maybe someone could model doing this.
> TNX es 73, Mike W3TS
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