I have run open wire in multiple configurations from
parallel #10's with 6" seperation to parallel #26 with
3/4 spacing. I have tried it twisted and tried it not
twisted. The balance meausred with various RF current
meters was always within 10% and basically within the
error of the meter.
I never ran it down a tower like you do. Since you
don't describe your experience with the line near the
tower without twists it would be interesting to run
the experiment:
next to tower twisted.
next to tower untwisted.
moving away from the tower at a diagnal twisted &
untwisted
hanging in the open twisted and untwisted.
My experience has basically been on 160, 80 and 40 and
with a broadcast band transmitter down around 1 mhz.
The broadcast transmitter fed the openwire through a
link coupled tuner and termininated in a link coupled
tuner that fed a 300ft tall vertical. (it was another
engineer's design, I just got to work on it) I have
used openwire on the higher bands with good effect,
but I have not measured the balance in the line above
40M.
Back in the 70's I ran some on 2M using a home brew
link coupled tuner. The 2M run was about 50ft and
connected to a beam that was designed around a double
extended zepp driven element. My longest run of
openwire was about 500ft on the BC band, but usually
my runs are less than 200ft, so I can't speak to its
behavior out to thousands of feet (multiple
wavelengths). My experience is that the "need" for
twisting is overblown in runs less than a couple of
wavelengths. Neither did the untwisted open wire
effect the pattern of the 2 meter beam with its
directely fed double extended zepp driven element.
That antenna was measured on an antenna range and had
18db forward gain, 25 db front to back and a nearly
perfect pattern. If the feedline was radiating it
would have screwed up the pattern something fierce.
That's my experience take it for what it's worth.
73 W9OY
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