1. ham radio cubical quad
The Cubical Quad Antenna
beautiful isn't it?
No, not your personal style? Well trust me it would grow to you once you finally build a
cubical quad over a tower and you earn some noise in the bands, and you realize it is
possible to hear a pindrop in Mongolia on your own reciever.
Ok so what's the major deal? I would rather let a number of the true experts tell you exactly
what the story is rather then open myself approximately the long barrage of devoted Yagi
afictionado's which will undoubtedly blitz me with nonsense. So first a brief often repeated
history lesson :
1. Just what is a cubical quad antenna?
2. Compared to a dipole antenna, what are the directional radiation characteristics of any
cubical quad antenna?
3. Approximately how much time is either side of any cubical quad antenna driven element
on 14 mhz?
4. Have you considered cubical quad spreaders and crossarms and how many inches do you
need make them? Do I need more coax?
5. What exactly are cubical quad antenna hubs?
6. Cubical Quad vs Yagi
7. Do I Need To use dielectric grease?
8. Can a cubical quad use traps?
OKAY Slow down, first lets enter in the back machine a little:
Back in 1951 Clarence Moore a Christian Missionary and engineer at the radio station loaded
with the Andean mountains of Ecuador, designed a two loop antenna he referred to as a
Cubical Quad. He developed this antenna to resolve issues caused by large coronal
discharges when using a yagi beam antenna in the thin air of higher altitudes. These coronal
discharges were periodically litterally Melting the Yagi antennas. His patent does feature a
mention and illustration of the two element unidirectional "quad", and describes the total
wave loop concept.

2. Cubical Quad Versus a Yagi antenna
Why do a lot of people repeat the Cubical Quad is the better antenna? Well for starters you
might have twice the level of element material inside the air. A yagi antenna is 1/2 wave
length per element. A one element 1/2 wave dipole is equivalent to the driven element of a
yagi antenna. With a few small size changes. Every element of a Cubical Quad antenna is
really a full wavelength long. More antenna material or twice the "capture area" is
incorporated in the air. Meaning you'll have a better chance of hearing someone over a quad
antenna versus a yagi antenna, and also this isn't taking into consideration the noise
advantage of the Cubical Quad which I will talk about a little later.
Ok, so twice the capture area over a cubical quad "Just What Exactly?" you say? When a
dipole has parasitic elements put into it, to become a Yagi Antenna, the Impedance changes,
actually it is down ALOT. From 50 ohms right down to 16 ohms or perhaps 12 ohms
depending on the antenna. I am not going to get into a lot of techno jargon, although the
impedance relates directly to the current and voltage with the antenna that develops RF.
Simply speaking...in case the impedance is not near to the coaxial impedance (50 ohms) not
quite as much power will likely be radiated from the antenna. Here's exactly what the techno
jargon amounts to: We now understand that on an antenna to function properly, its
impedance should not be too big or too small. It ends up that it is probably the fundamental
design parameters for just about any antenna, and it isn't easy to design an antenna together
with the right impedance - particularly more than a wide frequency range demanded by most
amateur radio operators. This is the reason virtually all commercial made yagi antennas have
some sort of matching device, such as a gamma match or similar. All matching devices
possess some loss ( no exceptions ). The Quad antenna is created now a days, that it can
be spaced in order that it may be fed with 50 Ohm cable. A very good match! No matching
devices! Less loss. All of this besides the reality that the complete wave length loop in the
cubical quad antenna has more gain then the comparable yagi antenna. I understand,
however, you heard that W blah, blah, blah says no. Have you ever seen pictures of the
cubical quads from him or some other online expert naysayer? Me Neither.
So before I recieve into just what the real experts say.......you realize guys which may have
actually built Cubical Quad Antennas versus the Yagi antenna, and used them. Lets conduct
a simple Eznec Pro4 demonstration of a simple 2 element Cubical Quad versus a Yagi
antenna. Same boom length, same height 35 feet above ground. This the most recent
expensive version ($1500 now) in the software, which only not many guys use, as the 35
years old version is already free. Its outcomes are vastly different.... its 35 years old
technology versus todays.........Anyway:
12.4 dbi gain at 12 levels of elevation (the takeoff angle) F/B ratio -24 db
So there's a basic 2 element cubical quad antenna. At 35 feet of height.
Now lets discuss a optimized element spaced 2 element yagi, and on the same boom length

3. 11.1 dbi gain at 14 degrees of elevation F/B ratio of -8 db
Ok so whats the gain difference?? 1.3 db gain. And thats with all the Yagi spaced to ensure
that its at maximum gain, so thats the cheapest db gain differential there is certainly. Period.
Admittedly you can space the Yagi Antenna elements longer, or just like the quad for better
front to back ratio, but the gain drops to below 11 dbi! I just gave the Yagi some optimization
because on the very same 6.5 boom length of the cubical quad the final results are only
terrible for the Yagi, like 2 db down versus the quad! "Online Experts" also have simple
causes of explaining how antennas work. After they attempt to explain the yagi versus
cubical quad, thats once you start to listen to all kinds of techno nonsense that explains why
they don't work any better. Don't believe some of it. Quads are better performance wise then
Yagi's PERIOD. Thats does not necessarily mean you need to own one immediately
because i will point out inside a bit.
Okay what do the real experts say about the differences between your Cubical Quad antenna
as well as the Yagi antenna :
"Clarence Moore's design eliminated interference from coronal discharge. "End effect", which
happens to be inherent with the Yagi, is absent in a quad because its elements do not have
ends. But other advantages appeared. The greater impedance mentioned within the quote
above means lower current and so lower loss in the transmission lines, and gain is higher
than that of a Yagi." Hey this is certainly directly from Wikipedia...go look it. Lets see what
others including the ARRL has said concerning the Cubical Quad vs the Yagi Antenna
Here we go Cubical Quad vs Yagi..........Advantages across a Yagi-Uda:
Rigorous testing of your quad antenna show the following advantages more than a Yagi-Uda
antenna.
Polarization
It is possible to change polarization from vertical to horizontal.
Multiband antenna
It is actually simpler to create a multiband cubical quad antenna, compared to a multiband
Yagi antenna.
Higher gain
The 2-element quad has almost a similar gain as being a 3-element Yagi: about 7-7.5 dBi. A
3-element cubical quad has more gain compared to a 3-element Yagi. However, adding quad
elements produces diminishing returns. Quoting from William Orr, "Whereas parasitic beams

4. having twenty or thirty parasitic directors are efficient, high gain antennas, it will seem ... that
maximum practical variety of parasitic loop elements for the quad array has limitations to five
or six." (Orr, p. 48)
Radiation resistance
Radiation resistance is affected by antenna height above ground, element spacing, and
environmental conditions. However, values will probably be more than to get a Yagi plus
more closely matched to some 50 Ohm coaxial feed.
Lower boom height
"A two-element, three-band cubical quad, with elements mounted only 35 feet above ground,
will give good performance in situations when a triband Yagi will never."[10]
Shorter boom
William Orr's book[11] shows a 10-15-20 meter, 2-element Cubical Quad with boom time
period of 6'10?.
Internally stackable
Interaction between antennas of any multiband quad are quite low, even if fed with a single
feed line. (Orr, 1959, pg. 63)
Lower radiation angle
According to K0SR[12] the state that cubical quads "open the band earlier", which
demonstrates that they exhibit a cheaper angle of radiation than Yagis, has persisted for half
a century despite the truth that computer models disagree. He posits how the vertical sides of
every element actually radiate the low angle component.
Disadvantages when compared with other antennas
Bandwidth
If tuned for optimum gain, the bandwidth for a 3-element cubical quad antenna is restricted:
Deviation from the design frequency will unbalance the near-resonance condition in the
parasitic elements. However, lengthening the director elements, thereby sacrificing
approximately 1 dB gain, provides for much broader bandwidth.
Maintenance
A quad can be a 3 dimensional antenna so maintenance can be hard. In spite of a tilt over

5. tower, tall ladders or a bucket truck may be required. You will find devices that will enable the
tilting of the tower to the floor to function on a cubical quad antenna, rotator, or tower. It
works by letting the quad loops swivel out of the way. Once the tower is with the operational
position the weather are locked into position (the locking mechanism is powered by gravity).
This is no longer mentioned concerning the Cubical Quad from the ARRL, but deserves
mentioning. "Cubical Quads are quieter then Yagi's". Why? Unfortunately Yagi Antennas
especially ones on top of towers are prone to precipitation static. This is because the Yagi's
all have pointed sharp element ends, these protruding elements build a large voltage
differential between your ends of the antenna and also the charged atmosphere during
storms even should they be far. This produces a discharge through the antenna in the
atmosphere and that shows up as noise inside the reciever. The larger the antenna the
worse the issue. If someone disputes this, they have never been to a contesting station
where all of the higher Yagi antennas are of limited or no use on account of static. Cubical
Quads do not have this concern. The Cubical Quad has no ends! This is a loop without
protruding ends, and thus no precipitation static. The voltage differential remains there but on
the Quad it can be down the middle of the loop. In fact that is why the Cubical Quad was built
to begin with! To eliminate Atmospheric static. And it also worked.
So to say that a Cubical Quad should not be quieter then a Yagi is merely wrong. It is
actually quieter at times. Period. It goes for virtually any Loop antenna versus any Dipole ,
Vertical or Yagi. Those can suffer from precipitation static from time to time. Now this does
not necessarily mean always a Cubical Quad will be quieter then a Dipole. The noise in your
antenna or any antenna depends greatly upon a number of other noise factors, like where it
is actually placed, how near you house it is actually mounted, how high it can be, whether it
be hearing signals from all of the directions (verticals) or maybe one direction (beams). Local
noise from the neighborhood, In addition to precipation static affecting dipoles and yagi's at
high heights. However is really a Cubical Quad or even a Loop ever noisier then this Yagi or
possibly a Dipole in the same operating position. NO. They can simply be quieter, and quite
often these are.
As for me, I actually have a couple of issues with a number of these statements stated
earlier, mentioned in books and through the ARRL:
Under Higher Gain, the part about diminshing returns with more elements. So as you grow
past 5 or 6 elements, each element is not going to contribute any extra gain. So what?? The
amount of people of HF convey more then the 6 element monoband beam antenna? Me ... I'll
take any other gain I could get.
Under Disadvantages: The bandwidth of the antenna ; with computer software today can be
produced as wide or perhaps a sharp as you would like, yes it can do effect gain somewhat,
but Eznec designs include shown this to get minimal about the order of tenths of your DB, not
anywhere near 1 DB gain.

6. Under Advantages: Its much easier to Make a Cubical Quad then this Multiband
Yagi.........NO it isn't...this is merely wrong. its tougher beyond doubt.
Under Disadvantages: The constant maintenance issue here on Wikipedia & the ARRL has
become glossed over. The Cubical Quad is equipped with maintenance issues. The wires get
lots of attention from birds ( like birds sometimes hitting them at 30 mph ) goodbye wire. But
moreover for years ICE and ICE Storms was the downfall from the Cubical Quad. This is
certainly still true, this along with high winds ( a northeaster ) can produce a Cubical Quad
look like a ball of Christmas lights which you used from this past year pretty quickly. This has
been addressed by Cubex as well as other Cubical Quad manufacturers, but nature is never
completely tamed. Years back the quad spreaders were made out of Bamboo, when you can
believe that, now much stronger fiberglass spreaders, will give you through most winters.
In addition, i think, whats not mentioned is definitely the cubical quad antenna dimensions
.....the Cubical Quad is a major ANTENNA. As i have said 3 dimensional but furthermore
BIG. In the end you might be using twice the size elements as being a full size Yagi! And it
will be a struggle to obtain it all around cleanly each and every time you need to do
maintenance. While there is something in the marketplace now called "Quad Lock" which will
help greatly with bringing the antenna up and down. I have the regular inside the ball park
cubical quad antenna formula link below
Ok Yagi owners, see I bashed it a little bit. You guys happy? No. Okay Well then your not
gonna such as this either:
I am just a packrat, meaning I collect things I'm interested in to your fault. Its a personality
trait I litterally possess a difficult time managing. So one thing I have collected over the years
as concerns this hobby is magazines and magazine articles and books. So as you are
already thinking, We have collected virtually ever component of written information I have
ever seen around the Cubical Quad, beginning with the QuadFather of Authors. The
extremely brilliant Bill Orr. More on him in the minute
Ok returning to Clarence Moore for a bit, after his invention:
Well Clarence Moore continued to found International Radio and Electronics Corporation
(IREC) in Elkhart, Indiana which had been renamed Crown International in the 1960s at the
suggestion of his wife Ruby. Crown International manufactured electronic devices including
power amplifiers. Clarence armed with his new quad antenna invention started entering dx
contests. Clarence quickly got the attention of Lew McCoy a really Big Gun during the
1960's. Lew was actually a "wide spaced" Yagi guy (typical of your times). Well Clarence and
his awesome new antenna toy, the Cubical Quad, was stealing each of the dx from Lew
McCoy with his fantastic dx buddies, while they were using 4 element Yagi's while Clarence
was just by using a 2 element Quad. Since Lew only lived 100 miles from Clarence he and
his awesome buddies drove up there to discover what was happening. It absolutely was he
then then realized the superiority from the Quad after seeing is believing and making use of

7. Clarence's radio equipment and talking with him. Lew McCoy then went to serve as a
technical advisor for the ARRL. Although he reported that this ARRL wasn't as excited about
the Quad while he was (Somethings never change). Even though Lew stated for them
emphatically that this Quad had 1.8 Db gain over a 1/2 wave dipole, and they also should
consider doing more articles about it. Because he was employed by the ARRL occasionally
his job would be to monitor foreign broadcasts, he did this with another amateur operator
there who used a comparably sized boom length Yagi. Across a 2 year period and A huge
number of stations monitored, 100% of times the Quad heard the stations louder and first
and later on then a Yagi. If you wish to discover this for your own eyes, pick up Lew McCoys
excellent antenna book "Lew McCoy on Antennas" it absolutely was written a little while ago,
and has great real life info and stories in it.
The storyline about Bill Orr "All about Cubical Quads" and also the Cubical Quad basically
repeats a comparable story of that of Lew McCoy as he was Big Gun as well as a ARRL
technical contributor. If you have never been aware of Bill Orr or read some of his books you
might be really missing a lot of good information. You should buy any one of his antenna
books now, he's a really good writer, all things are made very easy and he's quite funny,
even funnier then me. He has written an extremely famous book about cubical quads that
helped popularize them during the entire U.S. Other Big Guns including George McCarthy
W6SUN "Much more about Cubical Quads"and John Koszeghy K2OB "The High
performance Cubical Quad Antenna", and large Big Gun Bob Haviland W4MB "The Quad
Antenna" have likewise written good books about Cubical Quads and their advantages and
construction.