As the arts advance towards
their perfection, the science of criticism advances with equal pace.
Edmund Burke (1729-1797)
The antenneX Mission
By Jack L. Stone, Publisher
journal like antenneX often has to live and deal with hasty judgments made by individuals who read just one or two issues or just one or two articles from those issues. The hasty judgment has many forms but boils down to this sort of statement: Back in [199x], antenneX supported the harebrain ideas of [The Mad Hatter], the creator/developer/author of the [XYZ] antenna. One of the most famous rumors is that antenneX "supported the CFA." While we encouraged experiments, we only reported the "story" of the CFA. The good, the bad and the "fade." Such reporting of any exotic concept is in the best interest of any reader seeking information about the concept before making a decision to pursue the concept in some costly manner. This is where the bleeding edge lurks and where such needs to have new and/or exotic concepts walk out into the bright sunshine instead of relying on the shadows of "rumor mill" or expensive pursuits. This is why I chose the "Quote of the Month" at the top of this column.
BTW: To see our latest report "Whatever Happened
to the Commercial CFA" about the status of the CFA (from origins to now), see last
Conversely, any who would spread
beliefs as being factual based only on the rumor mill does a disservice to their friends.
Such has caused many to purchase some sort of commercial version of a "magic
antenna" only to find it is worthlessand money wastedand perhaps one less
"friend" to rely on for advice! Then, embarrassment sets in and the now
disappointed person doesn't want anyone to know he/she was a victim of a farce. Thus, the
cycle continues unbroken without such true and vital info made available to the general
public. However, this is the service antenneX provides and the numerous emails of
thanks for those who have taken the time to read our product reviews and
"stories" tells us many are now better informedsome are thankful for
saving them money and others for helping them to pursue the right direction in finding a
good solution for their particular needs. Check some of our reader feedback letters:
Since antenneX became an on-line journal, we have met with many purportedly new antenna ideas, especially for newer and more compact radiating systems. Among the antennas that have appeared in these pages are the following items, shown by their acronyms and by their expanded names or applications.
|ANTAP||Antenna for Apartments|
|CFA||Crossed Field Antenna|
|CTHA||Contrawound Helical Toroidal Antenna|
|CUBES||Cube-C, Double-Folded Cube-C, ADR, Cube-L|
|DDRR||Direct Drive Ring Radiator|
|DLM||Distributed Load Monopole|
|EHA||Electric & Magnetic managed fields|
|Fractals||Fractured geometric managed shapes|
|Isotron||Word contractions combined to name the device|
|MicroVert||More word combos - Small Vertical|
|GAP Super C||Product name coined by GAP antenna company|
|TeslaVert||Nickola Tesla's Coil theory applied to a vertical|
The list itself comes from the announcement for a book published by antenneX called SMALL & EXOTIC ANTENNAS: A Compendium of Evaluations. The volume contains selected articles from our archives that directly deal with and evaluate some of the antenna ideas. Among the evaluations, you will find applause for sound and workable ideas as well as detailed critiques of ideas that simply do not stand up to both theoretical and practical scrutiny by experts in both areas of antenna work.
In the early stages of the life of any
antenna, however, we do not have access to independent test results, detailed reviews of
mathematical foundations, or any of the other marks of solid antenna review. Very
often, we begin only with the words, ideas, drawings, and prototypes of an individual or a
small group of individuals who create what they take to be a new antenna or a significant
improvement of an antenna. On what basis can we, as a journal, adequately evaluate
submitted material that shows, explains, and sometimes even appears to promote the
OURS IS NOT TO PROMOTE BUT TO REPORT
The mission of antenneX is not to promote a product or the makers of a product. In fact, the journal does not itself evaluate antennas, although on occasion we have attempted to organize efforts to have an antenna evaluated to proper engineering standards. Individuals with the proper experience and equipment to do the job well and with the writing skills to report their results to our readers perform the actual evaluations. This is the case for all of the articles in Exotic Antennas.
antenneX exists to promote, encourage, and disseminate the results of antenna experimentation. Experimentation can take many forms ranging from basic antenna theory to practical techniques for the home craftsman. In many cases, the evaluation of practical ideas is the task of the individual reader: if he likes an idea, he uses it, but if he thinks the idea is dumb, he simply sets it aside. However, if an idea cuts across the grain of prevailing antenna fundamentals, then matters become more complex. In many cases, at the initial stages of an ideas development, we have only the words and materials submitted by the author with which to work.
What does it say on the Hatter's Hat?
On the label in the hatband it says "In this style" and the 10/6 is the price. Hatters used to hawk their wares on the street and were noted for their bizarre behavior. In England at the time of Lewis Carroll the pound Sterling was (and is) the central unit of money. Prior to adopting decimal units, the pound was divided into twenty shillings and each shilling was divided into twelve pennies or pence. Amounts of money were written in various ways. The pound was represented, as it still is, by a "£" sign, the shilling by a 's' and the penny by a 'd' (for 'denarius', a Roman silver coin which was also used as the name for the English silver penny). So the meaning of £1-10s-6d is fairly obvious. But amounts below a pound were also written 10/6 meaning 10s-6d. An amount such as 10/6 would be pronounced "ten and six" as a more casual form of "ten shillings and sixpence."
Because antenneX encourages experimentation, even at
fundamental levels, we do not, as a journal, reject seemingly new ideas just because we
are skeptical. Rather, we publish items that emerge from otherwise reputable sources
to give our readers information on the new idea. Many ideas later turn out to be
flawed, sometimes at a practical level, sometimes at the level of the underlying
theory. Our readers become evaluators and some eventually become reviewers of the
idea. The process is not quick or easy. Sometimes the developers of an antenna
concept may well blunt initial skeptical reviews so that an evaluation of an antenna idea
may require a considerable periodsometimes yearsbefore we have a general
expert consensus accompanied by internally consistent theoretical and practical tests.
THE BLEEDING EDGE
Since antenneX may be the first journal in this technical field to publish an idea and since we publish new experimentation with enthusiasm, it may appear that the journal gets burned when the final evaluations poke many holes in the now-tarnished idea. However, nothing could be further from the truth. We have entered the arena of publishing antenna experimentation with open eyes and full knowledge that some of the ideas will turn out to be bad ones. Hence, we know from the beginning that results will be mixed. What we cannot know on first submission is which ideas will stand and which will fall. We only know the test of time will determine that for certain.
Of further significance, antenneX is without any financial ties to any company or person who wishes to promote a new concept (or otherwise for that matter). Hence, we can publish the findings of any product critique without concerns about loss of financial support. We do not solicit advertisers and very few magazines can manage to keep their heads above water without such revenues. Thus, there is no outside influence to worry about when our writers do reviews. Our reviewers like that about antenneX and so do our readers!
"Bleeding Edge" is a play on words taken from the terms cutting edge and leading edge, which are both used to describe the newest, apparently most advanced stage in the development of something. Bleeding edge means that something is even more advanced than this, but often suggests that using it may be a difficult, unpleasant or painful experience.
Ideas do not always immediately prove themselves true or false. Very often, both the pages of antenneX and the discussion list will be filled with lively debate and rebuttal regarding the merits of a new antenna or the concepts behind it. When that occurs, we know that antenneX has done its job and is a component of the test of time. To repeat last month's "quote of the month:"
The hours of folly are
measur'd by the clock; but of wisdom, no clock can measure.
William Blake (1757-1827)
REVISITING HISTORICAL TECHNOLOGY TOO
Of course, antenneX exists not only for reporting the latest antenna experiments. There is room for practical antenna matters, for reviewing nearly forgotten technologies, and for exploring more fully some parameters of antenna operation that we often overlook. We often run items that help the newer antenna enthusiast tie together bits and pieces of lore into a more cohesive whole. But the core of our work is to encourage and to publish antenna experimentation. No matter what a hasty reader may wish to believe and feed to the rumor mill, that is our mission, and we shall stick to it.
VISIT THE GUEST ROOMS
The relentless attacks on our web site by pirates and the like has made it necessary to add more security to protect our material against such piracy. It's only fair that we know who enters the House of antenneX, so our guests will need to provide some minimal information in the process of obtaining a login. This includes using your real active email address without which a login cannot be received. Do not confuse this login with a paid subscription login. They are not the same and your subscriber login will NOT work in the Guest Room areas. Of course, you may choose to create your own login to the Guest Rooms using the same login as your subscription, if the system will accept it.
Along with the continuing fight against spam/virii junk, protecting our material and valuable bandwidth against piracy takes up a great amount of our timetime we can't really spare. The Internet is simply not the friendly neighborhood it used to be in the "old days" and more and more security must be installed to counteract these intruders. Thus, we have made the access to the Guest Rooms as automatic as possible for you to manage your own login.
In view of the above, we have overhauled the nine free and open-access sections that have always been wide open to all of our friends throughout the many years antenneX has been online. But, we must change with the times as the need dictates. I don't think the Internet will become more friendly in the near future and logins are becoming the rule rather than the exception. To repeat, most would like to know who they invite into their house. The same applies at the House of antenneX. It's really worth the effort!
This list pertains to those sections with free access now in our new Guest Rooms we have built and fully operating:
From the Shack
Patents (new room under construction)
We have activated a new login system for access to the above guest rooms and, the login can be totally managed by our guests. Above is a graphic of what you see as a login page to the new consolidated area, "antenneX Guest Rooms." This new page for logins is at this location now and available for your use:
Get you login all setup now at this URL:
We've really tried to make it easy while still fending off the bad guys, i.e., pirates!
As a result of this new programming, you will be able to obtain your own login, change it to update your info, change your password and delete membership if & when you desire without our help. Of course, the bottom link on the new page provides help if you still need it.
If you still need help or have questions about
our login areas, check this page first:
.....and, you can always get help here if you still have further questions: CONTACT
The new Antenna Discussion List is a infinite fountain of ideas making it a great "watering hole" for exchange of ideas, questions and answers on a wide range of antenna-related subjects. You will be in good company along with some of the brightest minds available. Were else would you have such free access to this level of expert advice? To participate or just read along on some very interesting subjects each month with 2000+ members from all around the globe, you are welcome to join us:
You are encouraged to contribute your thoughts on various subjects to a worldwide audience.
AN INVITATION TO CONTRIBUTORS
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 readershipfor 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 firstname.lastname@example.org . 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 forwe shall always make room for a worthy article.
To see details of our writing guidelines, please look at: Writing for antenneX
Subscribe for the Premium Feature Articles!
Enjoy these new concepts with our readership: Be sure your subscription is active so you don't miss these new and exciting concepts and more to follow. If you are thinking about subscribing or renewing, save 20% with a 2-year subscription. Just go to this URL and check on the Subscription option of your choice.
Keep the issues coming and stay on the leading edge of antenna technology!
~ BE SURE TO VISIT THE SHOPPING SHACK ~
Shipments worldwide ~ plus instant downloads
| Subscription | Books | Software | Antennas | Components |
IN THIS ISSUE
We again include many fine articles by our great writing team from around the globe. Now, allow me to introduce this month's line-up of content:
OUR MONTHLY COLUMNS (plus this one you are reading by yours truly):
FEATURE ARTICLES IN THE LIBRARY:
|Because the rhombic antenna, especially when terminated, offers very high gain, it has received more design attention than any of the other long-wire antennas. The straightforward basic design data sampled in Part 4 does not exhaust the significant variations on the basic configuration. One potential particularly suited to amateur service in the upper HF range is the possibility of operating a rhombic over a 2:1 frequency range, thus allowing coverage of 20 through 10 meters. We shall examine one tried and true design and try to find out the basic design premise that allows it to be successful.|
Height of an Antenna Above Ground is Critical
|Targeted for the basic understanding about this aspect of antenna technology, articles such as this will definitely increase your understanding of how the antenna game is played not about regulations, but what Mother Nature says is okay!. Antennas for transmitting and receiving follow the same rules of Mother Nature who tells us what one can or cannot do. In the "Rules" book, one can quickly learn more about the factors that effect an antenna than is apparent from other antenna books. And, this book uses only enough simple math necessary to get the point across. Graphs and diagrams are used throughout to further clarify. Whether a novice or old hand, you will find something useful and of interest.|
Meter Antenna System Impedance Matching: Part 2
show that actual network matching results, assuming the load impedance at the transmission
line source impedance is constant for that time when the other effects are stable, cannot
be exact. Quite clearly, it shall be shown that the matching network used effectively
changes the transmission line length in the process of tuning and matching the impedance
seen at its source point. The usual other experienced variations such as weather, are not
present and the measurements are made when temperatures are in the 70 degree Fahrenheit
range on a dry sunny day.
Since there are finite network losses, it will again, be shown that the conjugate match can not be exact but will be essentially close enough for all practical purposes, and maximum power transfer will be experienced. The transmission line is the 600-Ohm surge impedance type that is included with the W7FG 80 10-meter antenna.
Because the antenna and transmission line is close to the beam supporting tower, effects from the tower and beam will be experienced and shown to result in a departure of the calculated apex impedance from measured line source values. The beam supports the 20-, 15-, and 10-meter bands and the coupling that occurs with the wire antenna will be shown to be quite apparent.
End Fed Zeppelin
Zeppelin or Zepp has been around since the early part of the last century, but
how many of us really understand this strange antenna? Lets explore this seemingly
simple antenna and see how it works and how good it really is.
The Zeppelin antenna was developed for use on the massive German airships that flew in the early part of the last century. This antenna then became popular among amateur radio operators in the 1930s. The traditional Zepp has a 1/2-wavelength horizontal radiator fed at one end by a resonant length of open wire line. The term Zepp is sometimes used to describe a dipole fed with balanced line; however the dipole version of this antenna is correctly referred to as a center-fed Zepp or as a Double-Zepp. The true Zepp is an end-fed antenna it is defined by the antenna wire and the feedline. The thing that always seemed odd was the side of the open wire line that doesnt connect to anything how can this antenna work? Let's find out!
Impedance Measurement Error
article is written for all those who think that Ohms Law is a textbook theory, which
sometimes fails in real-life situations. When can you trust the data? While I answer this
question, I want to expose some questionable impedance measuring techniques, and to offer
some alternatives and analysis tools that can help minimize measurement error. And as the
title suggests, complex arithmetic will be treated in detail. Mainly this article is about
communication, as will be seen.
Some of the article's text may seem tutorial or remedial to some readers, but I want to be fair to the full readership by not making any assumptions of their skill level. I hope that whoever you are, you find this article helpful and readable. As such, I will try to keep this article less dry than the typical professional paper, while at the same time keeping it accurate and precise. However, most students of the subject material find that it is not easy to learn. It does indeed require patience and practice. But eventually you will do it by rote, automatically, and wonder what all the hoopla was about.
Some Preliminary Notes on the Gamma Match
e-mail regularly contains a question that appears in various forms, but has one theme: Why
have I not written anything about the gamma match? There are notes at my personal website
on various forms of series matching systems and notes on the beta match. These two types
of matching systems represent alternatives to the gamma match, especially when the task is
to transform the generally low impedance of a Yagi array up to the value of 50 Ohms, as
required by the most common feedlines used in amateur and other services.
Compared to a gamma match, series and beta matching systems are both simple and precise. Both systems make no alteration to the driven element, but add networks composed of transmission lines (usually) to the element feedpoint. The beta match does require that we initially set the driven element length to arrive at an optimal value of reactance relative to the feedpoint resistance, but the beta component is or is equivalent to adding a simple reactance across the feedpoint. The matching systems do not affect the radiation properties of the element.
As a consequence of these conditions, we may calculate the required values for series-matching or beta-matching components very precisely. In practice, the key factor affecting field adjustment of the systems is the accuracy of the velocity factor that we use in the calculations relative to the value that actually applies to the line used. If we know the velocity factor with measured accuracy (in contrast to the values we find in lists and specification sheets), we can often obtain the desired result with no need for further adjustment.
Well, there you have it, folksthanks 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.-30-
Best reGARDS, Jack L. Stone, Publisher
September 2006 antenneX Online Issue #113
Send mail to email@example.com
with questions or comments.
Copyright © 1988-2011 All rights reserved - antenneX©
Last modified: December 31, 2010