October 1966 QST
articles are scanned and OCRed from old editions of the ARRL's QST magazine. Here is a list
of the QST articles I have already posted. All copyrights are hereby acknowledged.
is a story of one Ham's experience in determining how the performance
of his Yagi antenna compared to his identically configured (number
of elements, height off of the ground, etc.) cubical quad antenna.
His location was a farm field in Tennessee, back in the mid 1960s,
so there was really not much in the way of obstacles to perturb
signals arriving at one antenna versus the other, except of course
when the direction of operation happened to have the antennas in
line with each other. Both antennas were tuned for optimal performance
at 14.22 MHz, which is in the high frequency (HF) band.
Yagi vs. Quad
Establishing Antenna Superiority Through Reception Reports
An artist's sketch of the spacious antenna site of W4RBZ. The
beams are mounted 80 feet above the ground on telephone poles
spaced 150 feet apart.
By Robert E. Fitz, W4RBZ
After more than 30 years
of hamming from a series of temporary and semi-permanent locations,
my first act upon retirement from the Air Force was to settle at
a permanent location on a small farm in Tennessee and install a
pair of the biggest telephone poles I could acquire.
many discussions I had on the ham bands regarding the Yagi beam
vs. the cubical quad led me to conclude that the ideal sport would
be the on-the-air comparison of the two; I wanted to know exactly
which antenna I should keep as the ultimate. These QSOs concerning
the Yagi and the quad did not convince me that either one of them
was vastly superior to the other. A big percentage of the quad men
seemed only to be comparing their quad against tribanders or small
beams that had been used in the past.
It seems to be pretty
well established that at the lower heights a quad has a definite
edge over the Yagi. However, I was curious to know how the two antennas
would compare when both were placed at a relatively high elevation.
The merits of Yagis and quads have been expounded through the
years, with it being a matter of opinion which antenna is the
superior of the two. W4RBZ was fortunate to have enough time
and real estate to erect both antennas and make on-the-air comparisons.
Here's what he found out.
A 20-meter 4-elemen t commercial monoband beam was installed on
one of the previously-mentioned poles. This antenna worked better
than any antenna I had ever used before at any location. About two
months later I installed a 4-element quad, using the fiberglass
arms and aluminum spiders available on the market. A coax switch
was mounted on the station control panel to permit instantaneous
switching from one antenna to the other for a rapid cross check.
At the time this article is being written, I have used the
two antennas for about three months and have checked both antennas
with over a hundred stations. Most of the stations that I asked
to give a comparative report were foreign; a definite effort was
made to concentrate on the long-haul boys.
Any good engineer
or analyst could point out a number of weaknesses in my system of
comparison. This I will concede. I have only the standard test equipment
available to the average ham; I don't have the capabilities for
installing model antennas or conducting elaborate laboratory tests.
My only motive was to determine whether a good commercial beam performed
as well as, the same as, or better than a typical cubical quad installed
at the same height at the same location by a ham of average ability
with ordinary facilities and equipment.
First of all, a
short description of the antennas is in order. The Yagi has a 36-foot
boom and was adjusted strictly in accordance with the directions
given by the manufacturer. The quad is mounted on a 30-foot boom
in a diamond configuration and was originally installed using the
dimensions given in a previous QST article1
and in use
by a number of hams. Both antennas were peaked to a fundamental
frequency of 14,220 kc.
This photograph shows some of the details of the quad and Yagi
Each antenna is on a separate telephone pole and the boom of each
is mounted exactly 80 feet above ground. The Yagi is about 30 feet
closer to the shack, and is nearer to the highway and power lines;
however, the quad is closer to some tall trees about 50 feet high.
Both antennas are raised and lowered by similar elevator-cage hoisting
As mentioned earlier, the quad was originally
installed using those element dimensions that seem to be most commonly
employed. During the firs two weeks of testing there was practically
no difference between the antennas. Then the quad was lowered and
completely retuned for maximum forward gain. This seemed to give
the quad an edge on some contacts.
After the quad had been
in use in this condition for about three weeks, one of the old antenna
experts from the West Coast suggested that my quad still might not
be peaked for maximum performance and suggested that I try his dimensions.
This I did. The quad performance fell off noticeably. For the next
25 or 30 checks almost every station giving a comparison reported
either that there was no noticeable difference between the antennas
or that the Yagi had the edge. This was most noticeable on the long-haul
contacts. Previously, VU2CK had reported on several occasions that
the quad had about a one S unit advantage; after this change, Karnik
reported that there was no noticeable difference between antennas.
The same was true with several 9M2, 9M6 and VK9 stations.
The quad was again retuned for maximum forward gain, and tests
I will only cite my experience with
the Yagi and quad installation. In general, there was practically
no difference in signal strengths on the short-haul contacts, and
there was seldom any difference on medium-haul contacts to stations
in Europe, Africa and the mid-Pacific. However, on the very-long-haul
contacts to the Far East, Asia and the South Pacific, the quad had
a fairly consistent 2-3-db. edge. On only a few occasions was there
a big difference in reported signal strengths; this seemed to work
both ways, with the quad being given a 2-3-S- unit advantage in
a few instances and the Yagi given the same advantage in a few others.
a number of checks, inconsistencies in the reports indicated that
the different angles of radiation of the two antennas had pronounced
effects. For example, on one occasion a JA, DU and YK6 were worked
in quick succession. The JA contact gave the quad the edge, the
DU reported the stronger signal from the Yagi and the VK6 reported
no difference in signal strengths. Instances of this nature occurred
I learned early in the game that, under ordinary
conditions of QSB and QRM, one switch-over between antennas did
not give a valid comparison; the signals from the two antennas were
generally so close in strength that several checks in quick succession
were necessary for the other station to be able to give a fair evaluation.
While my quad seemed to have an edge on long-haul contacts,
there were still times, under the varying condition of propagation,
that the Yagi put out a stronger signal. The type of antenna in
use at the" receive" end was definitely a factor. Shown below is
a summary of my last 100 reports, the results of which are typical
of my experience over the past three months. The quad was tuned
for maximum forward gain for these checks.
of note is that there was never any reported difference on long-path
contacts. This could be checked on only about a half dozen occasions,
but no one reported any difference between antennas on the few long-path
There are several factors, other than signal strengths
at the" receive" end of the circuit, that must be given consideration
in any final selection of the better of the two antennas. Even when
tuned for maximum forward gain, my quad has a better front-to-back
ratio: received signals were generally weaker off the back of the
quad. The Yagi has stronger side lobes; a number of times, after
checks with long-haul stations, a W station quartering off the side
would break in to tell me that the Yagi appeared to be stronger
during the test. This was also noticeable in reception. I also noted
that during periods of heavy rain the quad had considerably less
On the other hand, the Yagi is much
stronger structurally and mechanically. The Yagi was comparatively
easy to assemble and raise. Constructing and installing a 4-element
quad is like trying to handle a crowd of romantic octopuses. During
periods of high winds the Yagi seems much more stable and less inclined
to shake itself apart or to tear the telephone pole out by the roots.
During the tests I had lightning strike. At the time of
the stroke, both antenna were grounded at the station through a
Waters Protax coaxial switch.2
The Yagi, with its grounded
boom, suffered no damage. The quad driven element was burned and
cut in two and a small amount of damage was done in the station.
In summary, after three months of playing with the two antennas,
I have found that neither is overwhelmingly superior to the other.
I know I have two good antennas since they both perform well at
my location. For the average U.S. contact or during QSOs of 2000-6000
miles, my antennas seem to run about neck and neck. The quad has
demonstrated to me an advantage on the long-haul contacts that makes
a difference in pile ups; however, this was not true in every instance.
I have also learned that the quad must be carefully tuned at the
actual site of operation to acquire this advantage.
have a lot of playing to do. I am now trying to figure out some
easy way of tying the two antennas together and possibly feeding
them in phase to see what happens; to date I have come up with no
simple system of phasing two antennas 150 feet apart and at the
same height. I would welcome any ideas on this score.
also have a V beam aimed east and west. While I did learn that this
antenna outperformed a tribander, I haven't yet gotten around to
comparing it with my quad or Yagi on 20 meters. I also want to compare
a Yagi "Christmas tree" against a triband quad; this I intend to
do during the next few months.
I'm still not sure which
antenna I will finally keep. Only when someone notices an ad in
the back of QST listing an antenna for sale will it become obvious
which antenna I have selected as the best for my particular station.
However, I'll probably wind up keeping the antenna that succeeds
in riding out the Tennessee summer thunderstorm season!
Bergren, "The Multielement Quad,"
QST, May, 1963.
Protax switches are not designed to protect
equipment from a direct lightning stroke - Editor.