Date: Wed, 15 Jan 2020 15:58:57 +0000 (UTC)
From: Roger Parsons <ve3zi@yahoo.com>
To: topband@contesting.com
Subject: Re: Topband: Topband resource
<W8JI's experience with a horizontal dipole at 300 ft is often quoted as proof
that only vertical antennas are useful for 160m DX. This is not my experience
with a dipole with the centre at 320 ft and the ends at over 250'. In its
favoured directions it is equal to a <W4RNL half wave vertical array over a
very large radial system. It is unsurprisingly not as good off the ends, and
quite is useless for relatively local communications.
<I am also inclined to support Roger, G3YRO, in his use of a low dipole, having
myself successfully used relatively low horizontal antennas for DX in the past.
There are most certainly times when higher angles are useful for DX - and
possibly more frequently than <we imagine. There actually have to be, otherwise
Roger would never work any DX at all. Note, this does not mean that a good
vertical antenna is not often or even usually better than a low horizontal one.
Finally, the UK is small compared to many other <countries, but it is not
actually a tiny island. Roger's path to North America is over about 300 km of
land, and he is more than 10km from the sea in any direction.
<73 RogerVE3ZI/G3RBP
## AFAIK, W8JIs.. dipole was actually an inverted vee, with the apex
at 300 feet....with no info on enclosed angle.
Per the older arrl ant books, Inverted vees...with a 90 deg enclosed
angle are omni directional.
But they conducted that test on 80m, with an inverted vee up 60
feet, with a 90 deg enclosed angle. The vee was rotated 90 degs....
and signals 900 miles away did not change. No mention whether a real
CM balun was used.
## Plenty of 80m rotary dipoles and 80m yagis that perform
exceptionally well..at heights of 100-150 ft. That would extrapolate to
200-300 ft
on 160m. Years ago, a fellow In Ore had installed the 1st F12
160 rotary dipole.... which I believe was up aprx 120 ft. His 1st
contact
was a 4X4. Several folks with 2 el....shorty 40 yagis up 70 ft, report
that the shorty 40 yagi ate their 40m 4 squares hands down.
Some have had great success with a half wave sloper......used in
conjunction with a delta loop reflector...apex up. In some cases, a
half wave sloper
was used on either side of the delta loop REF. So 2 switchable
directions were obtained.
Jim VE7RF
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