
Amateur Radio
Amateur Radio is a communications service consisting of operators licensed and regulated in the United States by the Federal Communications Commission. Amateur radio operators, by regulation engage in emergency and other public service communications, maintain technical skills, and foster international good will via communications.
My personal interest in amateur radio focuses on research into and education about antennas and antenna modeling. The listings on this page link to some past and present research (and to some past research updated before posting on these pages). Since these are essentially working notebooks and not polished articles (for the most part), they may contain typos, misspellings, and a few grammatical infelicities. Moreover, they are subject to revision and updating whenever I discover something more accurate, more useful, or more interesting.

Tales and Technicals:
A Little History and a Lot of Antennas
From time-to-time, I shall post some yarns, mostly taken from my collection of old books, manuals, magazines, and handbooks. I shall also occasionally post from the pages of my notebooks some technical information that may be of use to fellow and prospective hams. To keep this index from being too long to use, I have placed many items in collected groups. So be sure to check the listings that appear to collect items together from time to time for additions. Since these are notes and some reprints of casual articles, there will be considerable overlap in places--and many large gaps in other areas. Nevertheless, let's begin with these items:
A Little History, a Little Humor, and a Little Seriousness
Antenna Modeling Software Notes
See also the "Antenna Modeling" series, linked in the Continuing
Series section of the index.
Practical Antenna Notes: Lower HF (Mainly) Vertical Antennas
Practical Antenna Notes: Lower HF (Mainly) Horizontal Antennas
- Back to Basics: An Antenna Primer for New QRP Operators (05-19-2007) (PDF)
- Just Tall. That's All. Some Principles of Portable Antennas
to Strive For (08-29-2003)
- Wi're We Using Wire? (01-19-1998)
- A Note on Wire Size and Material (08-08-1998)
- Blunting the Edge of Cutting Formulas (10-25-2004)
- 10 Frequency Asked Questions about the All-Band Doublet (6-3-2005)
- How Much Coaxial Cable? A Case Study (01-12-2008) (PDF)
- The Multi-Band Inverted-V from Many Angles (01-24-2006)
- The Zig-Zag Dipole-Doublet (01-01-2000)
- Unfolding the Story of the Folded Dipole(03-12-2000, updated 10-02-2006)
- Understanding the CCD (02-26-2006)
- Modeling the T2FD (06-07-1999, 02-17-2007)
- Notes on the Terminated Wide-Band "Folded Dipole"
(06-01-2000, 07-19-2000, 02-13-2004, 10-22-2005)
- Notes on Wide-Band Multi-Wire "Folded Dipoles" Parts 1 and 2
(05-01-2007. 06-01-2007)
- The G5RV Antenna System Re-Visited Parts 1-3 (05-21-2003)
- Notes on Mr. Windom's "Ethereal Adornments" (01-05-2008) (PDF)
- The Isolated Off-Center-Fed Antenna: Some Less-Explored Facets (01-09-2008) (PDF)
- 160- vs. 80-Meter Isolated Off-Center-Fed Antennas (01-14-2008) (PDF)
- The "Ideal" Back-Up Antenna for 80-20 Meters(09-08-2005)
- Some ABCs of A-B-C: Notes on Triangles of Doublets (02-15-2003)
- Resurrecting the Y-Doublet (05-16-2003)
- Notes on All-Band Use of Horizontal-Plane Loops(10-28-1997)
- A 40-Meter Star (04-13-2003)
- Horizontally Oriented, Horizontally Polarized Large Wire
Loop Antennas (03-29-1999)
- Horizontal Loops: How Big? How High? What Shape? (10-21-2004)
- Half-Wavelength Interrupted Loops: Their Evolution and Uses (03-01-2008) (pdf)
- Vertically Oriented Multi-Band Antennas (05-20-2000)
- The All-Band Center-Fed Inverted-L (03-06-1999, 06-14-1999)
- Straightening Out the Inverted-L (06-01-2005)(PDF)
- Long-Wire Antennas Parts 1-5 (09-01-2006)
- To Trap or Not to Trap (12-20-1997)
- Some Notes on Linear Resonators: Parts 1 to 3 (03-09-2006)
- Some Notes on NVIS Antennas (02-23-2008) (6 PDF items)
- Horizontal Heights and Sound Bites: A Short Note Relevant
to NVIS Antennas (06-20-2005)
- NVIS and ALE: Some Preliminary Studies
- Vertically Radiating Horizontal Antennas (03-15-1997)
- The IL-ZX Antenna for 40 Meters (06-30-1997, 12-27-2001, 09-27-2003)
- A Comparison of Closed and Interrupted Loop Antennas for 40
Meters (01-15-2006)
- An 80/40 Quad Design (03-25-2006) (PDF)
- Notes on Full and Shrunken 40-Meter Quads (12-30-1997)
- Some Notes on Lower-HF Wire Beams (09-07-1997)
- Notes on a Wire Beam for 80 and 75 Meters (04-09-1997)
- A Note on Substituting Wire Elements in Lower HF Arrays (03-10-2000)
- 80-Meter Wire LPDAs(04-01-2002)
- Some Notes on Antenna Bandwidth (01-22-1997)
- 40 + 30 = 50 (Not 70) (10-23-2001)
- Half-Length Dipoles (for 40 Meters) Parts 1 to 4 (12-24-2007)
- 80-Meter Dipoles and Inverted-Vs: A Graphical Scrapbook (12-26-2007) (PDF)
- Wide-Band 40-Meter Yagis Parts 1-3 (03-01-2006, 12-31-2007)
- A 3-Element Wire Yagi Design for 10.1373 MHz (03-25-2006) (PDF)
- Short Beams and Operating Bandwidth (10-05-1997)
- My Top 5 Backyard Multi-Band Antennas (08-11-2004)
(PDF)
- De-Mystifying the Modern Dipole Curtain Array
(05-01-2006)
Practical Antenna Notes: Upper HF (Mainly): Yagis and Relatives
- Welcome to Yagi-World (06-19-2006) (PDF)
- Horizontal and Vertical Yagi Orientation (10-13-1998)
- Lobe Formation With Height Increases in Horizontal Antennas
(04-30-1999)
- Modeling 6 Long-Boom Yagis (07-20-1998)
- What Can We Expect From a 2-Element Beam? Parts 1-5
(05-09-1997; re-written and updated 04-25-2006)
- Mastering Some Mysteries of 2-Element Beams Part 1 (05-19-2001)
- Mastering Some Mysteries of 2-Element Beams Part 2 (05-24-2002)
- 2-Element Yagis: How Short Can We Go? (03-25-2006) (PDF)
- The Monoband Log-Cell Yagi Revisited Parts 1 to 4 (07-14-2000)
- Some Aspects of Long-Boom, Monoband Log-Cell Yagi Design (03-26-2006) (PDF)
- The G4ZU Bird Yagi (04-02-1997, 03-01-2005)
- Coils, Linear Loads, and Capacity Hats: An Overview of
Small Loaded Yagis (01-17-1998)
- Director/Driven Element 2-Element Yagis: Some Ideas for 12 and
17 Meters (07-25-1999)
- Using Moxon Rectangles for WARC-Band Antennas
Part 1: Some 17-12 Meter Ideas (05-01-2000, 08-04-2000)
Part 2: Some 30-17-12 Meter Ideas (06-01-2000, 07-04-2006)
- A Truly Portable Moxon Rectangle for Nearly No-Tool Field
Assembly (02-01-2003)
- Notes on the V-Yagi (06-12-2007)
- Is the V-Yagi a 3-Element Moxon? (06-12-2007)
- The Inverted-U as a Field Yagi (06-12-2007)
- The Inverted-U Yagi on 20 Meters and an Alternative (06-12-2007)
- Modeling Yagis by Equation Parts 1-2 (12-01-2005)
- Designing Moxon Rectangles by Equation and by Model (10-01-2000)
- Moxon Rectangles (General Index with Dimension
Calculator): 22 Items (02-28-2005)
- The Elusive Moxon Nest (06-01-2003)
- Moxon-Modifying the C3-Type Tri-Bander (06-01-2002)
- Stepped-Diameter Moxon Rectangles for 20 through 10
Meters (04-01-2006)
- A Tale of 4 Beams: The X, the Hex, the Square, and the Rect (09-01-2000)
- Yagi Element Diameter Differences Do Make a Difference (07-01-2000)
- Notes on Reversible Yagi Arrays (09-01-2003)
- I Want to Build a 3-Element Yagi Parts 1-4 (08-01-1999)
- Stacking Yagis 3 Items (09-17-1999)
- 1-2-3: 1 Boom, 2 Bands, 3 Elements Each (03-07-1998, 04-16-2007)
- Three Forward-Stagger 5-Band Yagis from ON4ANT
(08-28-1998, 04-18-1999, 07-16-1999)
- Dream Beams 2 PDF Items (07-01-2007)
Practical Antenna Notes: Upper HF (Mainly): Other HF Arrays and Questions
Practical Antenna Notes: VHF/UHF (Mainly)
- 2 X 3 = 6 (07-25-1997)
- Moxon Rectangles for 6 Meters (02-03-2003)
- 6-Meter B-Antennas: A Dipole and a 2-Element Beam (04-04-2007)
- Experimental Omni-Directional Antennas for 6-Meters
(12-27-2001, 01-20-2006, 03-31-2006)
- Route 66: 6-Meter 6-Element OWA Yagis in 9 Versions (05-01-2005)
- The 64-(Euro-)Dollar Question (01-01-2004)
- Phased Yagis, EDZ Beams, and Landstorfer-Sacher Yagis
(07-28-1999, 09-16-1999, 04-10-2000, 02-14-2004)
- The Half-Square on 2 Meters: Parts 1-3 (04-12-1999, 07-18-2002)
- Improved Antenna Performance for VHF FM: Some Basics, Some Options, Some
Hurdles (04-01-2007)
- Some J-Poles That I Have Known: Parts 1-4 (01-08-2002)
- What is a Slim Jim? (11-01-2006)
- Is COCO Your Cup of Tea? (04-01-2008) (PDF)
- Modeling Biconical Antennas (02-01-2008) (PDF)
- The Moxon Rectangle on 2 Meters (10-01-1999)
- Building a 2-Meter Moxon (11-01-1999, 12-18-1999)
- Simplifying the Turnstile Moxon Rectangle Fixed-Position
Satellite Antennas (10-01-2001; 06-01-2003)
- Some Notes on Turnstile Antenna Properties (03-28-2006) (PDF)
- What's Wrong With This Turnstile Stack? (05-15-2002)
- Notes on the Batwing Parts 1-3 (03-01-2004)
- Notes on the OWA Yagi (03-26-2006) (PDF)
- Expanded Coverage for the 6-Element 2-Meter OWA Yagi:
142-150 MHz (01-04-2006)
- In Pursuit of Better VHF Quad Beams: A Work in Progress (04-21-2001)
- Notes on Medium-Length 2-Meter Quads and Yagis (01-24-2003)
- Circling the Square Quad (05-01-2004)
- The Quad Beam as an Amateur Satellite Antenna (07-01-2004)
- A Collection of 220-MHz Yagi Designs: Parts 1-4 (03-29-2001)
- Multiple Reflectors for Long-Boom Yagis (10-06-2001)
- Appreciating DL6WU Wide-Band Long-Boom Yagi Design: Some
Preliminary Notes (11-02-2001, 12-05-2004)
- Long-Boom Yagi Sidelobe Suppression (04-27-2002)
- Sidelobe Attenuation and Suppression: Parts 1-3 (10-20-2005)
- Preliminary Studies of Long-Boom Yagis for 420-450 MHz (04-28-2003)
- Long-Boom Trimming Yagis: An Accumulation of Data Main
Text (12-10-2004) (PDF)
- Long-Boom Trimming Yagis: An Accumulation of Data Reference
Graphs (12-10-2004) (PDF)
- Long-Boom Yagi Rules of Thumb: A Comparison with
Modeling Data (01-01-2005) (PDF)
- 2-Meter and 70-CM Yagi Stacks: Preliminary Studies:
Parts 1-4 (09-01-2005)
- A 70-CM Wide-Band, Long-Boom Yagi with High Sidelobe Suppression
(07-01-2005)
- Scaling and Adjusting VHF/UHF Yagis (12-01-2002,
07-09-2004, 08-30-2007)
- An OWA Family of 2-Meter Yagis From 6 to 12 Elements :
Parts 1-2 (08-02-2002)
- Extending the 2-Meter OWA Family: Parts 1-3 (10-01-2004)
- Notes on a 6-Element Wide-Band 2-Meter Yagi (12-26-2002)
- The OWA Family Moves to 220 (09-02-2002)
- Wide-Band Utility Yagis for 420-450 MHz
- A 2-Meter/70-Centimeter Dual-Band Yagi for the Home Builder (08-08-2007)
- Some Basics of Very-Wide-Band Yagi Design : Parts 1-2 (10-01-2002)
- The Flat-Plane Reflector for 432 MHz (11-08-2001)
- Modeling the Double-Diamond for UHF (12-01-2001, 11-12-2002)
- A Diamond Jubilee (05-19-2007) (PDF)
- Corner Reflectors Revisited: Parts 1-3 (04-18-1999)
- The 3-D Corner Reflector (07-01-2003, 05-05-2005)
- Corner Arrays for Personal Communications (10-01-2001)
- Split or Continuous LPDAs for Personal Communications? (10-22-2002,
11-12-2007)
- Planar Reflectors: Parts 1-4 (05-01-2005)
- Corner Reflectors Revisited Again: Parts 1-5 (10-01-2005)
- Planar and Corner Reflectors Revisited (08-12-2004) (PDF)
- The Prismatic Polyhedron and the Planar and the Corner Reflector : Parts 1-2
(06-16-2007)
- Special Needs Call for Special Antennas: The X-Array (11-01-2004)
- Modeling the Dual Rhomboid: Parts 1-3 (08-16-1999)
- High-Gain, Wide-Band Yagis for 10, 6, and 2 Meters (09-01-1999)
- Quagi and Yagi on 2 Meters: Some Preliminary Notes (04-16-2001)
- A 3-Moxon Polling Array for 914 MHz (08-01-2000)
- Horizontal Polling Arrays (07-01-2006)
- A Short Note on Tilted Vertical VHF Antennas (04-01-2008) (PDF)
- The Case of the Curly Collinear (06-01-2004)
- A 100-1000 MHz "Utility" LPDA (12-01-2001)
- CAP Emergency-Beacon Direction-Finding Antennas (05-05-2003)
- Some Notes on FM BC Antennas: Parts 1-5 (04-10-2003)
- LPDAs for the 400-800-MHz Television Range: Parts 1-2 (03-20-2003)
- Notes on Axial-Mode Helical Antennas in Amateur Service (06-01-2005) (PDF)
- Notes on Axial-Mode Helical Antennas in Amateur Service :
Parts 1-3 (10-20-2005) (HTML)
- Notes on Fixed Satellite Antennas (05-01-2006)
- Some Overlooked Antenna Basics for DX and Off-World
Communications (05-01-2006) (PDF)
Transmission Lines, Impedance Coupling, and Construction
- A GAP in Our Understanding of Feedpoints (01-16-2005)
- Notes on Home-Built Antenna Hardware (06-14-2006)
- 12 Ways to See and Love Your Feeders (05-19-1998)
- Some (Old) Notes on Home-Brew Parallel Transmission Lines
(01-06-2000, 12-28-2001)
- Values Along a Transmission Line (11-25-1998, 10-16-2006)
- When is a Quarter Wavelength Not a Quarter Wavelength?
(02-20-1998, 07-15-1999)
- Some Aspects of Series and Parallel Coaxial Cable
Assemblies (12-26-2001)
- Stub Matching: A Review (05-01-2005) (PDF)
- Some Notes on Modeling Hybrid Transmission Line Stubs (05-01-2002)
- The Beta Match: 2 Views (02-02-2005)
- Series Matching: A Review (02-05-1999)
- Some Preliminary Notes on the Gamma Match (10-01-2006)
- Some Further Notes on the Gamma Match: What MININEC
Models Report (11-01-2006)
- Voltage, Current, and Impedance Along a Transmission Line
(04-01-1997)
- Transmission-Line and Tuner Calculation Aids (01-01-2005)
- An SWR-Feedline-Reactance Primer: Parts 1 - 2 (12-01-2004)
- A Common-Mode Current Picture Show (08-21-2006)
- The Impedance-Transformation Properties of Common 4:1 Balun Types Parts 1 to 4 (04-01-2008)
- Whose Afraid of a Little Matching? (04-04-1998)
- The Matching Question Redux (05-25-2007)
- Notes on a Wide-Band 50/75-Ohm Coax Feed System for Low HF
Band Dipoles and Vees (11-29-1997, 06-27-2007)
- Link-Coupled Antenna Tuners (updated 05-20-1999,
12-30-2000, 03-01-2004, 09-12-2004, 08-04-2006)
- Link-Coupled Antenna Tuners: A Tutorial: Parts 1 - 5 (11-25-1997)
- Delta, ATUs, and Losses (03-28-1998)
- An LCL/LC ATU (04-01-1996)
- The Balanced-L Network (12-13-2002)
- Rotator Direction Controllers (01-21-2001)
- How Accurately Must We Aim a Beam? (01-22-2001)
Continuing Series
- Antenna Options: a series of articles appearing on an
irregular basis in QEX. The basic theme of the series is that, whatever the
interest in antenna design, construction, or use, the amateur always has options. The more
we understand our options, the better decisions that we shall make.
- Antenna Modeling: a series of articles on
antenna modeling specially prepared for antenneX. The series aim is to help antenna
modelers get the most benefit and least anguish from their programs.
- An-Ten-Ten-nas: a series of articles for 10-10
News on antenna basics having special relevance to 10-meter operation.
- Antennas From the Ground Up: a series of articles
on antenna basics originally created for Low Down, the journal of the Colorado QRP
Club. The emphasis is largely on lower HF and wire techniques.
- Amateur Radio Continuing Education: a series of
articles prepared over several years for the annual Proceedings of the ARRL National
Education Workshop. The pieces range in scope from a full-scale proposal for a
technical education series down to using a blackboard more effectively in the classroom.
There are also links to some other educational sites.
HAMCALC: A Special Note. Numerous articles refer to HAMCALC, a suite of utility
calculation programs developed for hams by George Murphy, VE3ERP. The information in the
articles gives Murph's address for obtaining the current version on CDROM. Due to a bout
of ill-health, HAMCALC is no longer available on CDROM. However, you can obtain HAMCALC from this link to
the CQ Magazine site and download the current version of the suite in Zipped format. The
site provides instructions for installation and use.
These links carry a lot of valuable information and ideas, ranging from antenna
fundamentals to advanced topics in antenna design, modeling, feeding, and building. In
addition, some provide links to other sites.
Commercial Antenna
Manufacturers and Vendors: A collection of known sources, offered because these
pages often contain educational as well as commercial information.
Other Amateur Radio Links:
A small collection of links to organizations and linkage sites to help you find other good
sources of information.
A Final Note
You will note an absence of reviews, analyses, and evaluations of commercially made
antennas in the notes at this site. It would be inappropriate for me to remark on such
antennas without having the antennas at hand and the appropriate range and equipment for
testing them. These notes relate to antenna types and designs over which I have design
control and are generally aimed to assist you to understand their operation. Even specific
designs are not intended for uncritical replication, although a number of them have been
successfully built and used. Still, the goal is not to produce a compendium of antennas
for you to build. Rather, the object is to assist you to understand the antennas that you
do build, use, or simply think about.
You may note that I do not attach my name or call to any antenna design. There are 2
main reasons for this action. First, I prefer to call antennas by their technical titles,
except where there is already a traditional name that brings ready recognition of the
technical features of the antenna. In a few cases, where an antenna's originator deserves
recognition and a technical label might be combersome, I have given the antenna a name.
Hence, I refer to the Moxon rectangle rather than to a 2-element, rectangular,
dual-coupled, parasitic array. I claim no originality for any antenna design in these
notes and have patented nothing shown in any article. Second, the aim of these notes is to
assist you--in small bits--to understand the antennas involved and antennas in general.
Hence, most of the designs are derivative from existing designs taken from texts and
handbooks. Nothing in the collection deserves re-labeling with my name or call.
Please do not attempt to download the entire site using software designed for blind
downloading. If you wish a record of the entire site, antenneX periodically
produces a CDROM with the entire site on it. However, I have kept most (but, alas, not
all) of the items at the site short enough to read at a single sitting. Pick something of
interest, read, and digest. Then pick something else. Let your wandering interests be your
guide. If you wish to read more on a subject, by all means, select a related item. Or,
look in other good sources for information on the subject. This site is collection of
items cast at an intermediate level. Hence, it is far from the last word on any subject,
whether you think of basic theory underlying a matter or about very practical construction
and operation aspects of an antenna or system.
When you begin to track the items at this site, you become a companion down the path of
antenna explorations that I have followed. Be certain that you are ever alert to pathways
that are a function of your own interests. This pathway is not the only one, and it is far
from the perfect one. But it has been and continues to be both a good and interesting one.
It has been my high pleasure to receive e-mail and regular mail that suggests these
materials are of educational and technical service to a broad spectrum of individuals,
both in the United States and around the world. Numerous items have appeared in the
newsletters and other publications of amateur radio groups. The formal and informal
distribution of some of the material, both as written and in translation, in areas where
bound publications are unavailable or prohibitively expensive suggests that the energies
used to develop and place some of the notes has been productive. So much to learn and so
little time to learn it, but always time to share what I have learned along the way--lest
it be lost.
Tales & Technicals: the CDROM
As a convenience to those who may pay for on-line time by the minute, have long-distance phone charges, or who have run out of paper while downloading items, the site is now available on CD-ROM. The cut-off date for the most recently updated version is December of the most recent year. The CD-ROM is available from