Topband: Looking for experience with DHDL

[Don Kirk]

Hi Rick,

You might take a look at a document you can download on a simple website of
mine that describes what I called a Terminated Bowtie receive antenna.  I
created this document while investigating the DHDL design.  After I created
my document, Rudy Severns (N6LF) published a document commenting on my info
(below are links to my Terminated Bowtie website, and to the N6LF document).

Terminated Bowtie website URL:
http://sites.google.com/site/terminatedbowtiereceiveantenna/
Rudy Severns (N6LF) comment document:
http://rudys.typepad.com/files/wd8dsb-comments.pdf

I definitely thought their were characteristics of the DHDL that could be
improved upon and that's what led me to the Terminated Bowtie design, but I
don't have enough property to build a full size Terminated Bowtie per my
design, so I have never been able to compare its actual performance with
its predicted performance (but if you have room, you would be the perfect
test subject).  The only disadvantage I see with the Terminated Bowtie
design (if it works) is the feedpoint location compared with the feedpoint
location on the DHDL.  Based on the gain of the full size Terminated
Bowtie, I would recommend a 20 dB preamp with it.

Just FYI,
Don (wd8dsb)

On Wed, Jan 31, 2018 at 10:19 PM, Richard (Rick) Karlquist <
richard at karlquist.com> wrote:

> I recently built a 70 foot long 35 foot high DHDL that can be pointed east
> or west by reversing the feed/termination.  I tested it in recent
> 160 meter contests either west to JA or east to the US East Coast.
> The comparison RX antenna was a low full size 160 meter inverted vee
> with the apex at 40 feet.
>
> The DHDL didn't exhibit any advantage to JA, and only exhibited
> advantage to the east coast with a small number of stations.
> When it did have an advantage, it sounded like 3 or 4 dB as the
> 100 degree lobe width would indicate.  It modeled very well on
> EZNEC.
>
> It was fed using a 16:1 impedance ratio "binocular" core balun
> transformer. It appeared to be in good working order based on it being very
> deaf to the north and west when aimed east.  This is in comparison to the
> low inverted vee which is basically omnidirectional.
>
> The DHDL experience reminded me of my attempts to build beverages
> over my high conductivity ground.  A JA beverage was very deaf
> to the USA, but didn't make JA pop out of the noise vs a low dipole
> or even the TX vertical.
>
> Can anyone share their experience with this design.  It is possible
> I am doing something wrong?  What is a better design to try?  I
> should mention that I have 20 acres available, so I can go as big
> as necessary.
>
> 73
> Rick N6RK
>
>
>