[Hallicrafters] Re: Dipole antenna

[Glen Zook]

A vertical is excellent for DX, especially on 160, 80,
and 40 meters.  However, for the "close in" stuff it
doesn't do a very good job (too low of an angle of
radiation).  I have a HyTower and a parallel dipole
that I use when operating on 80 and 40 meters.  For
stations out to around 700 miles the dipole wins
"hands down".  For stations over 1000 miles away the
HyTower usually wins.  For those between 700 miles and
1000 miles it is a "crap shoot" as to which one will
be better.

I can receive quite well on both antennas but the
other stations have problems with me at the distances
listed above.

In the past I have used phased verticals on 40 meters
(90 degree phasing, HyTower plus full sized 40 meter
vertical) which gives about a 4.5 dB gain in the
"forward" direction and about a 20 dB "null" off the
back.  At "right angles" there is still about a 3 dB
gain.  I can "flip" the pattern.  My suburban lot is
such that the only place that I can put the antennas
is such that the maximum gain is either towards JA or
South America.  I have gotten up before dawn on a
winter morning and started "running" JA (Japan) on CW
and was still working them after noon local time (this
from the Dallas, Texas, area).  I have worked JA as
late as 11:30 AM local on SSB.  Some people say thay
this cannot be done.  However, I have the QSL cards to
prove it.

I am now in the process of getting my phased verticals
going again.  The 40 meter full sized vertical is in
place along with the HyTower, the phasing controls are
all new.  Am just looking for some RG213/U to make the
equal runs to both antennas.  My "usual" feedline on
the HyTower is 1/2 inch Heliax.  It is not that I use
Heliax on the HyTower for "low loss" particularly, it
is just that I had over 1000 feet of 1/2 inch Heliax
mostly in 100 foot sections.  There are 7 runs of
Heliax up my main tower and 3 runs up my "short"
tower.  It takes almost exactly 100 feet from the top
of my main tower to my main shack.  To use any
"poorer" type of feedline I would have to actuall go
out and buy something else!

The 40 meter vertical is placed such that I really
can't run Heliax without some problems.  Therefore,
since the coaxial runs to both antennas have to be of
equal length (equal "electrical" length) I really want
to cut both of them the same physical length from the
same spool of coax if possible.

Both the HyTower and 40 meter vertical have elevated
radials (12 on the HyTower and 6 on the 40 meter
vertical).  At one time I had 48 buried radials under
the HyTower.  However, the elevated radials (4 cut for
80 meters, 4 cut for 40 meters, and 4 "random"
lengths) do a MUCH better job than the 48 buried
radials ever did.

The low angle of radiation is one reason that a
vertical is often called "an antenna that radiates
equally as poor in all directions".  It is not
radiating poorly but just a a low angle of radiation
which is great for DX.  However, for working more
local stations the angle of radiation has to be higher
and that is where a dipole, or similar wire type of
antenna, is going to work better.

Glen, K9STH


--- David Hollander <n7rk at cox.net> wrote:

Forget dipoles and inverted vee's if you can't get
them up at least a 1/2 wavelength above ground, go
with a vertical or a sloper! You will get much better
performance. And I am not talking about trap verticals
with a ground rod.

=====
Glen, K9STH

Web sites

http://home.comcast.net/~k9sth
http://home.comcast.net/~zcomco

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