Book Review
PORTABLE WIRE ANTENNAS
by John W Hill KF7SQQ
Some months back, I purchased the latest edition (v2.1, 2015) of John W. Hill's excellent antenna compendium Portable Wire Antennas. And now having had some time over the holiday period to dig into the book, I'm mighty glad I did buy it! There are some really helpful hints for deploying antennas in portable or temporary situations. However, all of the designs presented in this book will work just fine in the home QTH environment as well. Although it is aimed principally at the licensed amateur radio operator, this book should also be read by the average shortwave listener, too! There's plenty here for all radio hobbyists to enjoy!
Portable Wire Antennas is described on the Amazon site as:
This is not a book on antenna theory. It does provide clear easily understood explanations on the principles of antenna operation, transmission line considerations, impedance matching, baluns, tuners, and the pros and cons of different types and configurations of wire antennas.
This book is written with the intention of enabling a newcomer to amateur radio to understand the theory and practical considerations of this subject without getting lost in mathematics and complex theory.
Portable, reliable HF communication is required for emergency management, expedition communications and recreational uses. This book is about selecting and constructing portable HF wire antennas that will provide maximum performance with low power, light weight and low bulk. All the information required to assemble antennas and antenna kits that can be deployed in multiple configurations is provided.
Special attention is given to wire antennas deployed at low heights above ground, a situation confronted by operators on the move. Special attention is also given to NVIS (Near Vertical Incident Skywave) communications, which is also optimum with low antenna elevation. NVIS propagation enables communications in the 50-500 mile range regardless of terrain and independent of repeaters.
With two or three low suspension points (8-20 ft.), one can deploy wire antennas that cover the 160-30 meter bands (those capable of NVIS propagation) with performance optimized for NVIS communication.
With a single high suspension point that can be improvised from one or two tall trees, buildings or cliff faces and one of the antenna launch systems described here, one can deploy multiple antenna options that can be configured from the modular antenna kit. These include inverted V resonant or random wire dipoles, long wire antennas, sloper dipoles and inverted L antennas for efficient all-band regional use. It also covers terminated V beam and inverted half rhombic beam antennas optimized for 20-10 meters while being broad band (no tuner required), low noise gain equal to or greater than a high dipole.
With two medium to high suspension points (15-80 ft. depending on the band), one can install half square wire antennas that produce high gain low angle radiation that is optimum for DX operation. Dropping one of the wire curtains converts the same antenna into a general coverage multi-band inverted L.
With the versatility of the modular antenna components described here, one can quickly assemble, deploy and dis-assemble and roll up high performance wire antennas that are adaptable to nearly any operating environment and communications objective.
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Over the decades, I've done my fair share of playing around with all sorts of HF and VHF antennas. And I've read quite a number of antenna books during that time. There are so many ways of stringing up a wire for transmission and reception of HF signals! But in recent times I haven't had the need to delve into an antenna book. So I had forgotten about some of the designs presented in this book. I realised that there are still plenty of opportunities for me to experiment with various antennas.
Because of my previous experience, I found that Portable Wire Antennas was an easy read - not too heavy on the theory, no maths (yay!!) and well written. However, new ham radio operators and inexperienced shortwave listeners certainly won't feel out of their depth when working through the book. There are plenty of useful diagrams and photos to help explain the designs in their basic forms.
Just a few of the antennas discussed include vertical ground plane wire antennas, folded dipoles, an all-band random wire dipole, extended double zep, the OCF dipole, horizontal loops, end-fed antennas, beverage receiving antennas, inverted half rhombics, and many more.
In addition, plenty of advice is offered on antenna related accessories such as transmission lines, antenna couplers, baluns and other transformers, along with helpful suggestions for deploying your antenna in a portable situation, antenna height, lightning protection and safety considerations. There are even several short chapters on radio wave propagation and propagation modes. There's also a useful bibliography referencing some well known general antenna books, plus web links to articles, some of which I had not seen before.
Parts of the text relating to SWR measurements, dBi figures and such will not be relevant to shortwave listeners who just require an antenna for receiving purposes. And that information can be easily skipped over without a problem. Indeed, some of these details might just arouse the curiosity of a possible prospective amateur radio operator of the future! Which is a good thing!!
It has to be said that none of these antenna designs is new. What John KF7SQQ has attempted to do is catalogue ways and means of deploying these configurations in temporary locations. So for those of us who enjoy our hobby out-in-the-field, this book will provide some fresh ideas to consider when undertaking a DXpedition.
But, as I indicated at the beginning of this review, all of the designs and ideas can also find a more permanent setup in the radio hobbyist's home QTH. Yes, there are other more detailed and theory-laden books available for those comfortable with higher-level maths, graphs, charts, etc. The purpose of Portable Wire Antennas is to introduce many options for consideration when going portable. To that end, the author has done an admirable job of writing a handbook that is easily accessible to many hams and SWLs. HIGHLY RECOMMENDED.
AVAILABILITY
This book is not expensive! Portable Wire Antennas is available in two formats - paperback or Kindle editions. I bought the Kindle version and it worked well in that format. Check online book stores for current prices.
73 and good DX to you all
Rob Wagner VK3BVW
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© Rob Wagner, Mount Evelyn DX Report, and contributors 2012-2020
Thanks - you convinced me! Just now purchased for my devices with the Kindle reader!
ReplyDeleteMr. Hill suggests that excessive SWR waves are pushed back into your transmitter and that heats up the finals doing damage to the radio. This is simply not so. However the rest of book is informative. Low impedance is what gets the finals in trouble. Check out July 1973 Ham Radio Magazine Pg. 73. Very good article on this!
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