I went for horizontal polarization with the feed point at the apex at
the top of the 80 foot tower. I used a quarter-wavelength RG-11 line
as an impedance match for the 100 ohm antenna feed impedance to 52
ohm RG-8 coax to the station. My baseline reference is the W1FB and
W1SE article in the October 1984 issue of QST (page 24) which details
all possible configurations. When I lost a few of my pine trees that
support the base leg to pine bark beetles this past summer, I had to
move the end supports. I was surprised as to the sensitivity of the
SWR to lengths of the three legs. Not having all three legs
reasonably equal caused a significant difference in the SWR. Guess I
was lucky the first time I put it up 20 years ago so on the new
configuration I constrained the insulator connections to the base leg
with wire rope clips. Over the years, I've ended up preferring
insulated wire over bare copper wire - just lasts much longer in the
high humidity environment. For K5KKV's benefit, the overall length
of the delta loop is 1005 divided by f in MHz which makes it a full
wavelength. For 80 meters that would three legs around 95 feet each
or a total of 285 feet/86 meters. Ken K5RG
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