Listener’s Library, June 1997
As things go, this is my “Back from Kulpsville” edition of Listener’s Library. There were quite a few interesting books for sale and on the silent auction tables. But this year what caught my eye was a series of books from one of our fellow ANARC clubs The National Radio Club. As most of you know, the NRC is a Medium Wave club. Their journal DX News has had some remarkably professional technical articles over the years, particularly in the area of antennas. Many of these medium wave designs have potential for Tropical Band listeners so they are worth a look by shortwave folks as well. All of the books we will examine here can be ordered from the
National Radio Club Publications Center
PO Box 164
Mannsville, NY 13661-0164
All the prices listed are for non-members. You get a better deal if you join the NRC.
THE NRC ANTENNA REFERENCE MANUAL
First printed in 1975 and update in 1995, The manual is a serious collection of articles published in DX News prior to 1974. This volume mainly concentrates on basic medium wave antenna construction including loop and longwire designs. Additionally there are a series of antenna amplification systems. All of the designs and electronics work are within the scope of the average hobbyist. Each design includes helpful illustrations. While many of the drawings are crude in appearance, they are complete and easy to follow. Included is the classic design for an Altazmuth Loop. In past years at Kulpsville you may have seen Dave Schmidt’s display of this loop antenna. It measures about four feet per side. Relax, there are also designs for a two foot loop that is easier to manage. You will also find basic information on classic Beverage design as well as tuned longwires. Remember folks, next time you plan to put up a “wave” antenna for shortwave, remember just how long one of these beasts needs to be to work efficiently on medium Wave. In amongst the construction articles you will find a lot of solid antenna theory that is widely applicable in the general monitoring hobby. Over the years I’ve built quite a few of the designs out of this book. (I’m a DC to Daylight guy, remember?) Loop antennas are great a busting through the noise and getting at the signal. If you are good with woodworking you can make some of these designs into beautiful pieces of furniture that you would be proud to show even you non-hobby friends. If you’re not good at woodworking (like me) you can just use the designs to scare people with. A four foot loop has a “Mad Scientist” look about it.
THE NRC ANTENNA REFERENCE MANUAL
There are a lot more things you can do at lower frequencies and volume two takes you down these paths. This book includes technical articles originally found in the 1974 through 1981 issues of DX News. There are several additional designs for loops and loop amplifiers, all of which expand upon those found in volume one. You will also find references to ferrite core loops that allow for high performance in a much smaller space than a full air core loop. Where volume two goes beyond is in the area of antenna phasing. Two antennas can be connected through a phasing unit to allow for significantly improved performance. Antenna phasing is an underutilized technology that deserves a good look by all radio monitors. This volume includes the designs of Mark Connelly WA1ION who you may remember won this years DXer of the Year award at the Kulpsville Winterfest. Once you get a look at the attention to detail that he places on his phasing unit designs you will understand why he is so well respected in the radio hobby. The articles break down the relatively complex process of phasing unit construction so that anyone can make a working unit and benefit from its use with almost any two lengths of wire. If you want to really see spectacular performance, apply phasing technology to a pair of beverage antennas. You’ll never turn back to a regular longwire again.
While the first two books are for the general hobbyist, these next two dig a bit deeper into the hard theory and design issue of antenna that many folks enjoy studying.
LOOP ANTENNA DESIGN AND THEORY
As I’ve already pointed out. The loop antenna design has a lot to offer folks at the lower end of the shortwave bands. This book digs deeply into the math and science that explains why these designs have so much potential for the radio monitor. You will learn about topics such as loop pattern distortion that can actually be used to the monitors advantage when it is fully understood. Further advanced loop construction articles can be found with special concentration on the use of ferrite rods for antenna construction. These ferrite designs have great potential for use on the lower shortwave bands and their inherent directionality can sort things out on a crowded portion of the bands. Again, several designs for antenna amplification are included. If you have an interest in taking the loop concept to its maximum expression, you need to give this book a look.
BEVERAGE AND LONGWIRE ANTENNAS DESIGN AND THEORY
I’ve saved the best for last as this volume has direct application across the shortwave spectrum. Many of us from time to time have strung really really really long wires in hopes of snatching a few hard to catch signals. Most of us have operated on the basis of “get the longest wire up possible and hope nobody gets choked by it”. Serious longwire antenna construction is based on sounder theory than that. This book puts down the foundation to allow you to construct wire antennas that are optimized for your particular application. The book includes a full technical analysis of the Beverage antenna design supported by diagrams and all that hard math that proves how things work. Further study of two-wire phasing is discussed including phasing unit designs. This book and a big roll of wire will change the way you do your listening forever.