In science the credit goes to the man who convinces the world,
not the man to whom the idea first occurs.
—Sir William Osler (1849-1919)

INTRODUCTION

hat the physician and educator said in his quote above from the 19th century is no less true in the 21st century. The history of electronics (not to mention almost every other field) bears witness to Osler’s correct summary. In fact, finding the individuals or groups who first came up with ideas has flourished in the fields of history and archeology. The chemical battery, once thought to be a post-Renaissance invention now traces its roots to ancient Persia. We have no clue to what the ancients thought about the terra cotta and copper device, nor do we know to what use—if any—they put it. However, we are able to replicate the primitive generator of direct current with common materials and derive from it perhaps a third of a volt.

But the ancient battery existed within a social climate far different from the so-called age of science that emerged after the medieval period. Compare the secrecy in which alchemists worked and recorded their work with the modern scientific journal. Today, scientists long for publication of their work and for work that is worthy of publication. Academics obtain promotions based in large part on the length of their publication record and to some degree on the prestigiousness of their publication outlets. Before the Renaissance, those who worked in areas that might counter or even confront the dominant belief structure of a society labored in secret, often alone, but sometimes within secret societies. Indeed, knowledge and innovation often succumbed to unwritten codes of secrecy within parts of a social order. The religious distinction between esoteric (available only to the inner religious circle) and exoteric (available to the laity) knowledge actually pervaded all specializations in societies and endured well into the trade guild movement, if not well beyond.

Esoteric knowledge with demonstrable outcomes—such as the tingle from a primitive battery—encounters two types of reactions. At one pole were the skeptics who distrusted what they could not understand. In modern times, the UFO, by virtue of its definition as unknown and unidentified, demonstrates the extreme form of skepticism that we sometimes call cynicism. If there are genuine UFOs, some claim (very loudly), then some group (perhaps a secret government agency) knows what they are and is conspiring to keep the knowledge from us. Ah yes, some love a good conspiracy some to an extent that a conspiracy is believed to be hiding behind every tree. Or, must we stick our hand in the fire to see if it really burns as we have been told?

GULLIBLE'S TRAVELS
The other pole of the spectrum consists of the gullible, who slavishly gorge themselves on every claim of something new, exciting, better, and (today) “scientific.” The gullible wish to believe. Once upon a time, in societies where religious powers also controlled the development of new knowledge, the gullible only needed to be told that the source of the new power was divine and revealed. In the age of science, we serve the gullible with claims of new principles of how the universe works. Indeed, the Einsteinian revolution in physics prepared the gullible for accepting almost any kind of claim, so long as it bore a certification of truth.

The complexities of modern society, with its social, political, and legal departments have produced a new type of certificate: the patent. He who holds the patent holds the rights over an idea and the foundation to instill conviction in the rightness of the idea. Bell was not the only telephonic innovator, but his patent application was first in line—and just barely. Sarnoff did not invent FM transmission and reception of analog information, but through his patent attorneys and his influence with the FCC, he took control of the idea, with the eventual suicide of Armstrong as one unanticipated outcome.

PATENTS: JUST THE BEGINNING
Skeptics may well and correctly argue that a patent is not a certification of the truth or correctness of an idea, but only bestows rights of commercial development upon the patenting party. However, this argument has little impact upon the gullible, who view the patent as the scientific equivalent of the religious imperator of both olden and modern times. The patent holder, with the services of an effective marketing department, can turn a patent into gold, no matter the merits of the idea itself. Conviction nowadays rests upon advertising.

We once thought that such antics were the province of those who sold products of dubious benefit. Real science was largely immune to such irregularities. However, we have only to turn to the plethora of quack medical treatments and devices—all patented—as we moved into the 20th century to understand the viral effects of unsubstantiable pseudo-scientific claims. Treatment devices that rested on electrical or radiation principles likely harmed more people than they helped, while they enriched the device makers and appliers. As the seemingly “new” principles underlying the CFA and EH antennas suggest, even the core of a science is not immune to revision, patent, and marketing.

Conviction, then, is a two-edged sword. For the natural skeptic who brings canons of reason to new ideas, conviction only occurs if explanations and demonstrations meet all of the cannons of mathematical and experimental rigor. Even then, credit goes out sparingly to the one or ones providing the required set of links to allow us to see the idea at work within a larger framework. For the gullible, a set of attractive claims (including claims of dire consequences for not believing) is sufficient to convert an unproven claim into an eternal truth. For the gullible, the loudness of a claim is often the only proof required. But, choosing to believe everything or to doubt everything, avoids the burden of having to think.

Unfortunately, we fail to appreciate the true extent of gullibility on modern society. It reaches into areas where we expect cold, calculating reason. Hence, decision-makers in commerce and government are as easy prey to unsubstantiable claims as are the purchasers of magic shoes that guarantee basketball prowess or externally labeled clothing that guarantees beauty and social success. We shall always have new magic antennas with impressive labels that may or may not perform to expectations.

In the end, he who convinces the world of a scientific idea may or may not deserve the credit he receives.

BUILD THE DISCAN - A NEW EXPERIMENT
What is a Discan? While it's not a Discone, it may be a close cousin. Our regular contributor, Dave Cuthbert has a new project for us as described in this month's issue of antenneX. Looks like both fun and an interesting device easy to build and experiment with using common materials.

Origin of the Discan:
The Discan is a cousin to the well-known Discone antenna. The Discone consists of a large inverted cone with a disk on top. The name Discone is a combination of DISK and CONE. The Discan substitutes a can (cylinder) for the cone, hence the name DISCAN. While the Discan is no match for the Discone, as far as bandwidth goes, one can find many more conductive cylinders than cones. Thus, many more designs yet to consider.

Household Items
This particular Discan uses items from the grocery and the hardware stores. A “2 lb.” coffee can is used as the thick bottom half and a rod and a washer form the thin top half.

Designing and Modeling the DISCAN
NEC-Win Plus+ (available at the antenneX Shopping Shack) was used to design the Discan. A model was built using 1948 segments. Simulation time is 23 seconds on my PC and is fast enough to try many different dimensions. A Current-Temperature plot of the Discan is shown in an illustration of this article. The reader will note the low current near the bottom of the cylinder. This makes the bottom of the cylinder relatively insensitive to what it is set on. You can even hold the bottom of the Discan in your hands without seriously detuning it. Indeed, building this one can be fun, easy and functional with more experimental options yet to try!

THE FISHBONE
First, the “fishbone” antenna, a slow-wave version of a centre-fed dipole, described here should not be confused with a much older and now largely defunct application of the label. In the 1930s, both U.S. and U.K. versions of a terminated fishbone array for HF reception appeared. In these arrays, each of the horizontal dipole “bones” was fed as an element in an extension of Beverage wave antenna principles to the reception of HF signals. See pages 339 to 341 of Laport’s Radio Antenna Engineering for a brief description of these other fishbone antennas.

The idea behind a “slow wave structure” antenna is to make regular, spatially periodic, variations in the rod geometry. This serves to lower the wave velocity and therefore the antenna length (size) at resonance for a given frequency.

The (new) fishbone antenna presented this month by Dr David Jefferies, another regular contributor to antenneX. His article puts forward the Fishbone as a member of the family of slow wave structure antennas and it offers ease of construction with a reduction in antenna dipole length to about 2/3 of the straight wire length. It is believed it can be adapted for the HF bands.

This experimental investigation follows on from earlier articles on the Zagi antenna, which is built on a dipole shrunk to about 2/3 of the length of a straight rod dipole. This was done by bending the wire into a zig-zag (in the wire Zagi) or by making a serrated plate dipole (in the plate Zagi). The references are to antenneX articles [1], [2]. In those investigations it was discovered that the reduction in resonant length was accompanied by reductions in radiation resistance at resonance, and in bandwidth. Thus, simple development of the plate Zagi gave an the idea for the Fishbone antenna shown above, only one of the new designs.

The Fishbone antennas in the pictures found in David Jefferies' article this month were mostly constructed and measured by a University of Surrey MSc student Georgios Pardalis in the summer of 2006. He also entered the models in the NEC simulation software (NEC win plus) and ran the models. The data were used for his MSc dissertation.

THE PURPOSE OF THIS JOURNAL
In my column for September 2006, “The antenneX Mission,” I wrote about a subject close to my heart — the purpose of this journal. It had been quite some time since I had reminded our readers of our original purpose when we set out some 20 years ago.

More than anything else, this journal has always been a “labor of love” for me. It is the reason I founded the antenneX magazine almost 20 years ago, knowing that running a magazine is a tough business and especially so since I planned to do it without the traditional revenue support from advertisers or outside investors. I wanted this magazine to always be able to write about any issue without concerns of losing the support from any of those type revenues. I am pleased to say, we have never steered from that course one iota. And, as a consequence, we have covered some very controversial developments throughout the past two decades. In the process, we have provided valuable factual information to more than 200 countries, even to the most remote regions of the globe. Hence, our readers are much more informed about the truth about all of the “new” devices as their stories unfolded in the antenna and antenna-related field. For more details, you are encouraged to read my column from September 2006.

Additionally, we were pleased to receive and publish in the October 2006 issue, a very special editorial reaction to my column written by one of our long-term readers and contributors, Dr. Jef Verborgt. Those two articles are located by the following links below:

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 time—time 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 numerous 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 protected sites with logins are fast 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!

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:

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.

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 manuscripts at 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.

Sneaking Up on 2-Element Common-Feed Quads
Part 3: Dual Band Quad Beams With Common Feedpoints
By L.B. Cebik, W4RNL

Finally. . .we are ready to tackle dual-band quad beams with common feedpoints. Like the dual band beams in Part 2 that used separate feedpoints, our new beams will rest ultimately on the series of monoband beam designs that we examined in Part 1. They will also adhere to the basic limits surrounding the study by using no more than 2 bands per beam where the bands have at least a 1.3:1 frequency ratio. Hence, our new combination beams will include versions for 17 and 12 meters, for 15 and 10 meters, and for 20 and 15 meters.

Build the DISCAN
By Dave Cuthbert, WX7G

If you’re looking for an antenna construction project that is a bit different, the Discan might interest you. Using commonly available materials you can build this wideband, 450 MHz antenna that will help your handheld radio hit those distant repeaters.

The Discan is a cousin to the well-known Discone antenna. The Discone consists of a large inverted cone with a disk on top. The name Discone is a combination of DISK and CONE. The Discan substitutes a can (cylinder) for the cone, hence the name DISCAN. While the Discan is no match for the Discone, as far as bandwidth goes, one can find many more conductive cylinders than cones.

Untuned Transformer Primary-Tuned
Secondary Impedance Matching
By Fred M. Griffee, N4FG (EE Retired)

An analysis of transformer link coupling impedance matching shall be discussed with emphasis on a tuned secondary-untuned primary design. The untuned primary will consist of a link-coupling approach bifilar wound on the secondary. A comparison will be made between the two impedance matching approaches and be shown to show little difference other than, perhaps, some minor wider bandwidth tuning characteristics. The final line current or power delivered to the load will be shown to be equal between the two approaches. The analysis will employ Termins’ theory rather than Everitt’s that is used in previous articles addressing link coupling and matching.

The Fishbone Antenna
A simple “slow wave structure” implementation
By David J Jefferies

First, the “fishbone” antenna, a slow-wave version of a centre-fed dipole, described here should not be confused with a much older and now largely defunct application of the label. In the 1930s, both U.S. and U.K. versions of a terminated fishbone array for HF reception appeared. In these arrays, each of the horizontal dipole “bones” was fed as an element in an extension of Beverage wave antenna principles to the reception of HF signals. See pages 339 to 341 of Laport’s Radio Antenna Engineering for a brief description of these other fishbone antennas.

The Grayzone CD-ROM
A tool to successful DXing on the low bands
By Marcel H. De Canck, ON5AU

In the words of the author: We may begin with a quotation from the book “Low-Band Dxing,” published by the ARRL and written by author: John Devoldere, ON4UN. I know John very well; he is a close friend of mine since 1960, and we have had many talks about low band DXing and antennas for nearly a half-century.

“The most important tool is still sunrise/sunset information. Today all computer-logging programs include a SR/SS calculator. But I still use the SR/SS tables in a booklet form. Its still faster than a computer program if you want to look up information for a certain date or for a certain period of time.”

“Why? You grab the tables any time and look up the required information in seconds. Just keep the little booklet within reach on your operating desk. The tables never get outdated, since sunrise/sunset times hardly change over the years”

John published more than a decade ago his booklet showing sunrise and sunset times over 500 different locations in the world (including 100 different locations in the USA) in tabular form. The increments were given per half month, (date1 and date 16). This small booklet was sold worldwide among the low-band DXers community and I believe there are only a few left.

With the Grayzone CD-ROM installed on your PC, the information is always available at your operating desk. A few mouse clicks and you have what you want to know. About 890 pre-computed worldwide tables are immediately available. The tabular form sunrise-sunset times for each location are given for three dates, (day 1, 11 and 21) for each month. These tables were computed with the included program “Grayline.” You can always easily add more table for locations in which you are interested. Even more you can create tables of any location with daily sunrise-sunset data. So, for hunted DX you know now exactly the sunrise-sunset of any day of the year.

Tables are not always easy to interpret, in particular when dealing with and comparing two locations, (your QTH and the target location). A world map indicating the grayzone at time intervals should be of better help. The CD has such maps in two presentations. First, in printable adobe files, second in a selectable wizard menu. 3 456 maps are available at a few mouse clicks for each month at the three dates and for 96 times a day, (each 15 minutes). It is easy to browse through the maps. The wizards have also the option to give you an animated picture of a chosen date.

You still prefer a hardcopy booklet! No problem you can print out the pre-computed tables including those compute by yourself. Even more you can make a booklet of all the maps as well, (36 adobe files).

Included on the CD-ROM are a number of useful utilities, including a Great Circle Calculator. Click for More info.

The Grayzone CD-ROM: A Review
By L. B. Cebik, W4RNL

ON5AU's CD-ROM is a collection of utility programs that can assist you in various ways relative to your DX interests. The Grayzone maps--still or animated--can help you refine your understanding of the shifting values in the course of a year and their relationship to auroral zones. The wizards alone are worth the price of the CD-ROM.

However, the stand-along programs that allow easy calculation of sunrise and sunset, or grid squares, or time around the world, or great circle information would also be worth the disk price. They are each handy, accurate, and unobtrusive--and, most important, very useful. You are likely to find yourself using all of them from time to time, whatever your communications interests.

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.-30-

Best reGARDS, Jack L. Stone, Publisher
jack@antennex.com
January 2007 antenneX Online Issue #117

Household Items This particular Discan uses items from the grocery and the hardware stores. A “2 lb.” coffee can is used as the thick bottom half and a rod and a washer form the thin top half.

Household Items
This particular Discan uses items from the grocery and the hardware stores. A “2 lb.” coffee can is used as the thick bottom half and a rod and a washer form the thin top half.