Vertical Antenna Discussion

[Julius Fazekas n2wn]

I missed most of the original exchanges, but FWIW,
I'll add some of the things I've discovered using
vertical antennas of various sizes and configurations
on 160 thru 30.

A vertical will perform much better if it is in the
open. In other words, away from trees and buildings,
particularly if the antenna is ground mounted.

With a ground mounted version, more radials, even if
very short, are better than a couple "resonant" ones.
Most of us are not blessed with acres and acres of
land, so the odds are you won't be able to put down
120  .3 wavelength radials on 160 for an "ideal"
setup. Most of my radials are around 30 to 40 feet
long, over poor ground, they are 18awg and I have
around 60 of them. For near field I figure I'm down
about 1dB from an ideal antenna, maybe less. I
probably lose more to tree foliage. That being said, I
do find raising the base (8 to 10' above earth) and
using even only two raised radials over the in ground
radial system to provide a notable improvement...

The higher the base of the vertical, the better the
performance. I had an 80M ground mounted vertical that
worked well. It's base was about 1 foot above ground.
I moved the base up approximately 8' in the same
location. The antenna was more competitive.

A current balun is essential for verticals. You can
make one easy enough with a plastic coffee can (about
6" in diameter) tightly winding 6 to 10 turns of coax
around it. More turns will be more effective for the
lower frequencies. You can use Elecraft's Balun Kit as
well for a cleaner setup. There is an emerging school
of thought that a balun on both ends of your coaxial
feed is worthy of consideration, particularly for Rx
on the top band.

Many folks think aluminum when thinking of verticals,
keep in mind that a wire vertical (assuming you have
supports: trees (both famous und infamous)) are great
performers and inexpensive.

If you want some gain, and don't want to fight with
radials, consider a half square. These antennas are
very forgiving and work like gangbusters IMHO. I have
corner fed them, which seems to be frowned upon by
some. A 40M half square will work well on 30 up thru
10 (although you will get pattern distortion as you
climb in freq) using a tuner in the shack.

The best place for a "tuner" when using a vertical to
cover multiple bands is at the base of the antenna.
You'll be matching the antenna, not everything between
the shack and the antenna. A simple L network can be
switched in for each band of interest. With the KRC-2
you can even automate the switching. The tuner in the
shack will help keep the SWR low as you exceed the 2:1
bandwidth of the antenna.

Folks are very creative with the limitations they have
for antennas. It always amazes me what works. I know
there are guys on this reflector with "challenged"
antenna setups that are amazingly competitive.

The key is understanding your QTH and what will work
best for your situation. Definitely read everything on
Cebik's site ( http://cebik.com/radio.html ). It's
free and sensible. Moxon's book is worth reading.
ON4UN's Low Band DXing is a book that is worth owning,
it has more "how to" stuff. The ARRL Antenna Handbook
is worth picking up (you can find used ones at most
hamfests, the information has stayed the same for the
most part for years). There are lots of sites on-line
you can check as well.

73,
Julius
n2wn
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