Mother Always Liked You Best!

INTRODUCTION
Why is it that Mother Nature seems to smile on some of us and not others, even though we may be intellectually equal? How are some able to speak to her and understand her better? Is it intellectual perseverance, coincidence, luck or all or some combination of these….or?

Our ideas must be as broad as Nature if they are to interpret Nature.
—Sir Arthur Conan Doyle (1859–1930), English author.

Take Maxwell’s Equations for example. It is absolutely fascinating that this specific arrangement of math symbols has withstood the Test of Time for 140 years and at a time when such advanced theories were difficult to prove experimentally. But, the 19th century seems to have been blessed as an "age of theoretical advancements" which made so many more physical inventions possible in the following century.

According to many, Maxwell's equations represent one of the most elegant and concise ways to state the fundamentals of electricity and magnetism. From them one can develop most of the working relationships in the field. Einstein described Maxwell's work as the "most profound and the most fruitful that physics has experienced since the time of Newton."

Theoretical ideas, such as Einstein’s Theory of Relativity, was the work of many people, but the greatest single advance was the formulation of what are now known as Maxwell’s Equations, named after that 19th century physicist.

As most Physicists, Engineers and other scholarly folks know, Maxwell was a Scottish physicist, born in Edinburgh. In 1864, at the age of 33, he calculated a set of four equations expressing the basic laws of electricity and magnetism.

Maxwell's four equations express, respectively, how electric charges produce electric fields (Gauss's law), the experimental absence of magnetic charges, how currents produce magnetic fields (Ampere's law), and how changing magnetic fields produce electric fields (Faraday's law of induction). Maxwell was the first to put all four equations together and to notice that a correction was required to Ampere's law: changing electric fields act like currents, likewise producing magnetic fields.

EVEN HIS EQUATIONS ARE MAGNETIC!
Even now, 140 years later, physicists look for new solutions (and/or replacements) to Maxwell’s Equations. For example, it is said that Maxwell’s Equations do not explain why two magnets attract or repel. They only allow us to calculate how strongly and in what direction the magnets are pulled. The big question of “why” has yet to be answered or so my research tells me.

Maxwell’s four equations are laws stating that magnetic fields and electric fields must always obey. In layman terms, without a single bit of math, the equations state this:

1^st Equation:
If you wrap an insulated wire around a nail and connect a charged battery to the wire, you make a magnet. The magnetic field created by the magnet must obey Maxwell’s first equation, Ampère’s Law.

2^nd Equation:
According to the second equation, Faraday’s Law, you can take a magnet and spin it around and around to make an electric generator.

3^rd Equation:
Gauss’ Law, the third equation, says static electricity (electric charge) must generate an electric field (voltage). You can see this on any dry day by shuffling across a rug and touching a doorknob.

4^th Equation:
The fourth equation says that magnetic charge does not exist, a great mystery that physicists are still trying to understand, or so I am told.

Maxwell showed that the four equations, with his correction to Ampere's law, predict waves of oscillating electric and magnetic fields that travel through empty space at a speed that could be predicted from simple electrical experiments—using the data available at the time, Maxwell obtained a velocity of 310,740,000 m/s. In 1865, Maxwell wrote:

Maxwell’s quantitative explanation of light as an electromagnetic wave is considered one of the great triumphs of 19th-century physics. Moreover, it laid the foundation for many future developments in physics, such as special relativity and its unification of electric and magnetic fields as a single tensor quantity and Kaluza and Klein's unification of electromagnetism with gravity and general relativity.

Thus, so many have stood on the shoulders of Maxwell’s foundation in this field of physics. The view at this “height” is a lot clearer for those who would seek the view. But, here remains the division — while some view a vast, empty desert, others see a wonderland filled with possibilities! If I may paraphrase, some ask why while some ask why not?

But, we do ask "why did Mother Nature smile so widely on Maxwell and others whose theories have withstood the test of time for so long?" And many were only limited to theory. Some call it genius! (My own view of this is if one is not a genius themselves, how would one recognize genius in present day—since they don't usually wear a sign—"I am a genius"?)

Some would say the above quote is aptly applicable to antenna designs, as there seems to be an abundantly endless amount of “shapes” that may be used in efforts to enhance performance. After more than 100 years, we are still finding new ways to bend wires to shape antennas—now, more recently the use of plates has been introduced for what is commonly referred to as Capacitive Plate Antennas—in efforts to shrink the device and that has led to more shapes and different materials to produce yet another class of antennas: "Capacitive Compact Antennas."

One extreme example of sophisticated wire bending is the “fractal” which has been of recent focus although the concept has been fatdipole.jpg (24684 bytes)

around a long time. Author, Werner Hödlmayr, DL6NDJ tried some new designs which were featured in recent articles in antenneX. Werner probably has conducted some of the most creative experiments of late on fractals with his Fractent Loops (see above pictures — note the pen for scale).

As to new shapes, we have that too in another article this month entitled “The HF Short Fat Dipole” by Douglas B. Miron, KCØNKY (see left). Miron is a new contributor to antenneX and kicks off with this very extensive article about his own antenna design. The article includes many illustrations along with his NEC2 and NEC4 simulations showing a 90% efficiency is possible. He employs a technique called "volume loading".

Allow me to introduce Miron:
Douglas B. Miron received B.E. and M.E. degrees in Electrical Engineering from Yale in 1962 and 1963. Doug then received a Ph.D. in Electrical Engineering/Control and Communications from University of Connecticut in 1977. He worked in industry from 1963 through 1967, and 1970 through 1979 and 1996—1997.

Doug was an educator at South Dakota State University from 1979 through 1996 and has been consulting since 1998. He has worked, taught, and published in nearly every major area of electrical engineering. Current interests are in small antennas and RF circuits.

MORE CHALLENGES TO MAXWELL?
One of Maxwell’s great insights was the inclusion of displacement current, the last term of Ampère’s Law, in the first equation. This has to do with what happens to electric fields when they change, such as when the static electricity from your finger arcs to the doorknob after walking across a carpet within a dry-air environment. The electric field around your finger suddenly drops to zero and this sudden change in the electric field generates a magnetic field.

Faraday’s Law, the second equation, says the reverse is true. If you change a magnetic field, (say, by turning an electromagnet on and off) you generate an electric field. In fact, electric and magnetic fields can keep working together, all by themselves, each changing from one into the other, sometimes for millions of years. The result is what we know as light, or radio waves, or gamma rays, or, in general, electromagnetic radiation. To see electromagnetic radiation that’s millions of years old, look up into the sky some clear starry night.

This month, we have two more articles from Bill Miller, KT4YE further defining his work regarding displacement current. No doubt Bill’s efforts to dethrone one of the great mathematicians will be read with many tongues-in-cheeks. But, who knows? Perhaps Mother Nature is whispering in Bill's ear. I believe his efforts and intestinal fortitude (guts) to go up against a 140-year old wall are well worth our time and full attention.

As I have cautioned Bill, there will be “lumps” to absorb in such an effort and the trick will be to prove his “replacement” equation(s) and theories. A difficult aspect will be conveying his “challenge” in a comprehensive manner—meaning some clear and concise math along with experiments, something that is much easier to do surrounded with all of the technology we have today versus that available to Maxwell. No doubt, Maxwell had his critics too.

We have the two articles by Bill this month on this subject to be followed up with a joint article next month combining the sharp minds of both Bill and Werner. They tell me that the article will include experiments. This type of effort is to be admired and I’m glad this magazine is able to publish such bleeding-edge concepts for our readers to enjoy—and provide more material for plenty of debates on our antenna discussion list from which we all can learn!

AN INVITATION TO CONTRIBUTORS
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antenneX thrives on the contributions of antenna experimenters, ranging from the informal home shop construction project to the theoretical investigation of basic antenna, feedline, and propagation phenomena. Over the years, we have published articles on the use of new or newly adapted materials, known antennas adapted to new circumstances, modifications of antenna structures, basic explorations of both common and unusual antennas, antenna modeling exercises, design improvements, antenna matching techniques from both a physical and mathematical perspective, evaluations of mini-antennas and their underlying theory of operation, new and patentable designs, propagation tutorials, and.... The list goes on, since no antenna-related topic is irrelevant to the readers of antenneX.

At the same time, antenneX has experienced continuous growth in its readership—for which we are appreciative. However, all readers can help us do even better. How? By submitting an article every now and then based on your current antenna work that may be useful at any level to other readers.

Among the engineering and researching readers, there are undoubtedly a number of unclassified and non-proprietary findings that antenneX readers would like to know. Among the practical antenna designers, there are ideas, tests, and numerous other practical findings to benefit our readers. Antenna builders very likely have some techniques to share with other readers. Besides the regular articles, we always have the home work shop column for shorter practical ideas and we always have the invited news and editorial column for information about new technologies, future advances, lost old but good ideas, and personal views on the good to bad things that are happening in the world of antennas and propagation.

If you are uncertain about whether your ideas merit an article, please feel free to send an outline to the general editor/publishers at submissions@antennex.com . Do not feel that you must be ready to be a regular submitter to write for antenneX, because we welcome the individual contribution as much as monthly articles. As well, do not believe that the slots in each issue are already spoken for—we shall always make room for a worthy article.

TWO MORE COUNTRIES JOINED LAST MONTH!
Countries number 189 and 190 just joined the listing of "Where in the World is antenneX?" As is our custom, we welcome the latest newcomers and try to tell a little about the countries, some of the history and any other things our research discovers that might be of interest. The US CIA's World Factbook is most helpful in this research. A warm welcome to these latest newcomers!

WELCOME Rwanda, COUNTRY #189
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Rwanda is located in Central Africa, east of the Democratic Republic of the Congo. It is slightly smaller than the US State of Maryland and is bordered by Burundi 290 km, Democratic Republic of the Congo 217 km, Tanzania 217 km, Uganda 169 km. It is landlocked without coastline.

The population is almost 8 million. Estimates explicitly take into account the effects of excess mortality due to AIDS; this can result in lower life expectancy, higher infant mortality and death rates, lower population and growth rates, and changes in the distribution of population by age and sex than would otherwise be expected (as of July 2004). Life expectancy is under 40 years.

In 1959, three years before independence from Belgium, the majority ethnic group, the Hutus, overthrew the ruling Tutsi king. Over the next several years, thousands of Tutsis were killed, and some 150,000 driven into exile in neighboring countries. The children of these exiles later formed a rebel group, the Rwandan Patriotic Front, and began a civil war in 1990. The war, along with several political and economic upheavals, exacerbated ethnic tensions, culminating in April 1994 in the genocide of roughly 800,000 Tutsis and moderate Hutus. The Tutsi rebels defeated the Hutu regime and ended the killing in July 1994, but approximately 2 million Hutu refugees - many fearing Tutsi retribution - fled to neighboring Burundi, Tanzania, Uganda, and Zaire. Since then, most of the refugees have returned to Rwanda. Despite substantial international assistance and political reforms - including Rwanda's first local elections in March 1999 and its first post-genocide presidential and legislative elections in August and September 2003, respectively - the country continues to struggle to boost investment and agricultural output and to foster reconciliation. A series of massive population displacements, a nagging Hutu extremist insurgency, and Rwandan involvement in two wars over the past four years in the neighboring Democratic Republic of the Congo continue to hinder Rwanda's efforts.

Rwanda is a poor rural country with about 90% of the population engaged in (mainly subsistence) agriculture. It is the most densely populated country in Africa; landlocked with few natural resources and minimal industry. Primary foreign exchange earners are coffee and tea. The 1994 genocide decimated Rwanda's fragile economic base, severely impoverished the population, particularly women, and eroded the country's ability to attract private and external investment. However, Rwanda has made substantial progress in stabilizing and rehabilitating its economy to pre-1994 levels, although poverty levels are higher now.

Communications
Telephones - main lines in use: 23,200 (2002)
Telephones - mobile cellular: 110,800
note: Rwanda has mobile cellular service between Kigali and several prefecture capitals (2002)
Radio broadcast stations: AM 0, FM 3 (two main FM programs are broadcast through a system of repeaters and the third FM program is a 24 hour BBC program), short-wave 1 (2002)
Television broadcast stations: NA
Internet country code: .rw
Internet hosts: 1,233 (2002)
Internet users: 25,000 (2002)

WELCOME Heard Island and McDonald Islands, COUNTRY #190
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These islands are located in the Indian Ocean, about two-thirds of the way from Madagascar to Antarctica.

These uninhabited, barren, sub-Antarctic islands were transferred from the UK to Australia in 1947. Populated by large numbers of seal and bird species, the islands have been designated a nature preserve.

Heard Island - 80% ice-covered, bleak and mountainous, dominated by a large massif (Big Ben) and an active volcano (Mawson Peak); McDonald Islands - small and rocky

lowest point: Indian Ocean 0 m
highest point: Mawson Peak, on Big Ben 2,745 m

Natural hazards:
Mawson Peak, an active volcano, is on Heard Island

Country name:
conventional long form: Territory of Heard Island and McDonald Islands
conventional short form: Heard Island and McDonald Islands
Dependency status: Territory of Australia; administered from Canberra by the Australian Antarctic Division of the Department of the Environment and Heritage
Legal system: the laws of Australia, where applicable, apply

Population:
uninhabited (July 2004 est.)

Economy - overview:
No indigenous economic activity, but the Australian Government allows limited fishing around the islands.

Communications - No population, but it has an Internet!
Internet country code: .hm

Extending the 2-Meter OWA Family
Part 2: Gain, Element Population, and Hybrid Designs
By L.B. Cebik, W4RNL

In a past 2-part series devoted to developing the optimized wide-band antenna (OWA) concept to full-band Yagi antennas for 2 meters, we examined a connected series of antennas ranging from 7 to 12 elements. That series elicited a number of requests for longer versions of the antenna, given its adequate but stable gain, very good front-to-back ratio, exceptional SWR curve across the band, and general attenuation of sidelobes to more than 20 dB down from the main forward lobe. The results have yielded more surprises discussed in this new series.

The CCD Experiments
By Joel C. Hungerford, KB1EGI

This month, I started looking at a thing I recently heard about on the antenna discussion list — a so-called CCD antenna. CCD stands for “Controlled Current Distribution.” It consists of a string of series tuned circuits and short bits of wire between them. The circuits are all tuned to the lowest frequency to be used. The current at each circuit can be set by the reactance of the inductor and capacitor. It seems a natural for the combination of the interlaced wire capacitor I used to tune the loop, and small coils, all wound on a long PVC pipe. What if one used a modest number of tuned sections, say 5 to 10, and increased the reactance as one progressed from the feed to the end of the pipe, following an approximate tangent curve. Could this simulate the current in a vertical, but in a shorter distance? Would it radiate? Just how does the tuning behave if I string together several sections all tuned to the same frequency, but with a different L/C ratio in each section?

Refinement of a Yagi-Uda 2-Meter 10-element Beam
By Fred M. Griffee, N4FG (EE Retired)

After Yagi and Uda developed the new antenna array design concept, others studied and contributed to the approach. There has been extensive analysis, design, and contribution to the original Yagi-Uda antenna approach since 1926. Fred models the seven-element Yagi-Uda Design using YO7.6 and NEC-Win Plus software. This series of articles are an example of the process of combining YO7.2 and NEC-Win Plus.

The HF Short Fat Dipole
By Douglas B. Miron KCØNKY

In the Spring and Summer of 2002, I designed and built a prototype Short Fat Dipole (SFD, 4 m high by 4 m diameter) for the ham bands from 75 m to 10 m. For almost the entire following year I had a series of equipment and noise problems that greatly retarded the operational evaluation of the prototype, but by Fall, 2003, these were all resolved. Now that I’ve been on the air, making contacts, and exchanging signal reports, I feel it’s time to tell the amateur radio community about this antenna. In this article, I describe volume loading, the design philosophy for this version of the SFD, some numerical parameter studies, fabrication, attempts at measurement, and operational performance. The last section of the article discusses some ideas for future development.

The Wideband 2-Element Quagi
By Dave Cuthbert, WX7G

Dave asks: "Would you like an antenna that the whole family can enjoy? Do you just need a good FM broadcast antenna? Or how about an antenna that needs no tuning and is built using “plumber’s delight” construction? Then read this article and I’ll introduce you to the Wideband 2-Element Quaqi."

Transverse Currents & Longitudinal Fields
Implications for the Future
By William C. Miller, KT4YE

In the 1860’s, James Clark Maxwell postulated the existence of Displacement Current as the mechanism whereby Alternating Current (AC) flows through a capacitor. It forms the keystone in a series of equations — often called Maxwell’s Equations — that are the basis of all Electromagnetic theory.

About a year ago, antenneX published the author’s 2-part article called, “Displacement Current Does Not Exist.” The article was prompted by the apparent failures to perform as claimed found in two classes of antennas — the CFA (Cross Field Antenna) and the EH. The inventors of both antenna types claim that they “use” displacement current as an integral part of the radiation process.

Bill's earlier articles argued that the derivation of the concept was flawed, and that Displacement Current did not exist. Despite substantial criticism from classically trained engineers and physicists, the author stands by the contents and premise. Nevertheless, the author was unable to answer the one question that appeared again and again: “If Maxwell’s Equations are wrong, what do you propose as an alternative?” Bill believes he now has found that alternative set of equations and once again, Maxwell has been challenged!

Well, there you have it, folks—thanks for listening and remember, the reading lamp is always on for you in the reading rooms. If I can be of further help, I'm just a Stone's Throw! away. August 2004 antenneX Online Issue #88
reGARDS, Jack L. Stone, Publisher jack@antennex.com