I have built and tested Langford's Phased Delta Flag Array. It was very
good. I have built this antenna on a small, remote island in the Bahamas. I
compared it with a DHDL and a single flag (same dimensions as one of the
elements of the array).
The antenna was very good. You can see and hear a drone-test of its pattern
on https://www.youtube.com/watch?v=JMujut_5FdY . I used a drone with a low
power transmitter flying around the antenna, more or less along a 1/2 mile
circle, with a receiver listening on the RX antenna array. The video starts
(and ends) in front of the antenna. You can hear the RX signal as it is
being received on a remotely operated Flex Radio receiver connected to the
antenna. Although not visible on the video, the front to back ratio shown on
the spectrum display of the Flex radio was about 25 dB (you can not hear the
signal off the back, even though the local noise is very low -- day-time,
with the nearest house about 10 miles away, and the nearest city, Nassau,
about 100 miles away --- i.e. as low noise as you can get these days.)
Bottom line: the Phased Delta Flag Array was better than my DHDL, and, or
course, better than a single Delta Flag (one of its elements). But the
difference was not large. Later, I reconfigure the Delta flag into a four
direction antenna (two delta flags at 90 degrees, with direction selection
like on a K9AY array). This turned out to be a far more practical antenna
than its phased, two element predecessor. I think that a dual delta flag,
with four directions is a pretty decent RX antenna with a 60 x 60 foot
foot-print and a single 30' mast.
73,
George,
AA7JV/C6AGU
On Fri, 13 Mar 2020 10:43:46 -0500
Mike Waters <mikewate@gmail.com> wrote:
FYI, I just found this page with many Dallas Lankford articles:
https://www.okdxf.eu/index.php/technika/80-antenarska-kolekce-dallase-lankforda
. Open the site in Chrome (or use translate.google.com), and it'll
translate from Czech to English.
On an old laptop here, I have many of his articles downloaded from his old
kongsfjord.no site before they disappeared. They were interesting to read,
but I never built any of his RX antenna arrays.
- Has anyone else?
- If so, what is the RDF of his best design?
- And how to they compare to a one-wavelength Beverage?
73, Mike
W0BTU
This page has more than just his amp but enough so you can
> understand it.
> If anyone has an interest, I have some more files in my computer.
>
>>
https://www.okdxf.eu/lankford/Hi%20Z%20PPL%20Loop%20And%20Flag%20Arrays.pdf
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