W6SDO.COM SAN DIEGO, CALIFORNIA USA
Here are the results for the first test.
The 17 meter band was chosen for this
preliminary testing since I have four
antennas to choose from on the 17 meter
band. Also, this band almost always has
signals that can be copied and stations
that can be worked.
The antennas that were selected for this
1. The hex beam,
2. An inverted V off center feed Windom
(a long wire at this 17 meter band with
good omni-directional characteristics
due to the inverted V construction),
3. My vertical dipole (to which I have
added the 17 meter band - more on this
4. A two wavelength horizontal loop
antenna which is attached to the garage
Each has its own advantages and
disadvantages and the shoot out
between them has been very interesting.
The four antennas can be set up to use
the four antenna selector switch buttons
on the front of the Alpha amplifier. This
makes A-B-C-D testing very easy and a
lot of fun!
The initial 17 meter observations
summarized below result from about 25
QSOs and 100 or more stations
1. The hex beam is always quiet (the
lowest noise floor) and has the strongest
signal for both transmit and receive
modes even though it is only about 24
feet above the ground.
2. The two wavelength horizontal loop
has an equally quiet noise level,
compared to the hex beam, but delivers
signal strengths that are about 6 db less
than the hex beam. Not at all bad for a
3. The OCF Windom inverted V has a
noise level that is usually 2 to 3 db higher
than the hex beam while producing
signal levels that vary between being
almost equal to the hex beam and being
as much as 4 db weaker. The signal
strength effect seems to depend mostly
on the direction of the source from this
4. The vertical dipole usually has a 3 to 6
db higher noise level, compared to the
hex beam, and usually produces signal
levels that are typically 3 to 6 db weaker
than the hex beam. The vertical does
much better on transmitting than it does
on receiving due to the higher noise level
that it produces at the receiving (my) end.
There are occasions, however, when the
antenna is used for transmitting that the
signal strength on the other end comes
very close to that of the hex beam - just
not very often.
This page will summarize the results of
various antenna comparison tests that
are being performed on the antennas
that are located on my small city lot.
These comparisons will be made
under the same band conditions by
using the A-B-C-D antenna switches
on the Alpha amplifier. Each of the
antennas that will be compared has
been designed to be the best that it
can be considering the limitations of
the site (and other rules).
The first group of tests will be focused
on the 20, 17 and 15 meter bands
where the three antennas that are to
be tested are equally proficient. The
antennas that will be compared are the
hex beam, OCF Windom and vertical
For this series of tests, the Hustler
based vertical dipole has been
modified to provide optimum
performance on the 20, 17 and 15
meter bands. This modification is
pictured below. Three resonant
dipoles, separated on 10 inch centers,
are fed from a common balun and
coaxial cable feed line.
This vertical dipole can be easily
reconfigured in a matter of minutes to
operate on any band from 6 to 80
meters using a few lengths of
telescoping aluminum tubing and band
traps from the Hustler antennas.
15,17 & 20 meter vertical dipole base.
Three band vertical test dipole
The results of the first test, conducted
on 17 meters, are shown in the column
on the right side of this page.
PRELIMINARY TEST RESULTS
|This page was last revised December 10, 2013