Building a compact Moxon: brief construction notes
For portable use (emergency ops or field days), the Moxon is popular due to its light weight and ease of construction.
A heavy-duty plastic cutting board, plexiglass sheet, or aluminum plate works well.
The typical operational characteristics of a properly optimized HF Moxon rectangle remain consistent across bands when scaled appropriately: Performance Value ~5.8 dBi to 6.2 dBi Front-to-Back Ratio 25 dB to 35 dB (at design center) Feedpoint Impedance 50 Ohms nominal ( ±plus or minus SWR Bandwidth (2:1)
Unlike many antennas that require an antenna tuner or a balun, the Moxon generally offers a natural 50-ohm impedance, allowing for direct connection to coaxial cable. hf antennas for all locations moxon pdf
: Though the "Moxon Rectangle" is synonymous with his name, only a small portion of the book resembles this specific design; however, his principles of rectangular shaping and critical end-spacing are foundational to its high front-to-back ratio and gain. Digital Availability
The design parameters for a Moxon antenna are crucial to its performance. Here are some general guidelines:
Raise the antenna at least 15-20 feet off the ground. Check the SWR across the band. If the resonant point is too low in the band, shorten the elements slightly. If it is too high, lengthen them.
| Design Parameter / Performance Metric | Typical Value / Description | | :--- | :--- | | | Two-element parasitic array (driven element + reflector) | | Physical Size | Approximately 70% the size of a conventional 2-element Yagi | | Boom Length | ~0.18 λ (compared to ~0.2 λ for a standard Yagi) | | Characteristic Impedance | ~50 Ohms (ideal for direct coaxial feed) | | Forward Gain | ~5.5-6.0 dBi (gain over a dipole) | | Front-to-Back Ratio | ≥30 dB (excellent rear signal rejection) | | Frequency Bandwidth (SWR < 1.5:1) | Good for typical amateur band segments (e.g., 28.0-28.7 MHz) | Building a compact Moxon: brief construction notes For
A popular approach for fixed-station use is to build a , combining elements for several bands onto a single boom. One acclaimed project, "Moxon Mania," details the construction of a four-band Moxon beam covering 20, 15, 10, and 6 meters. This design uses fiberglass spreaders for insulation and a single feed point, significantly simplifying the feed system. While effective, multi-band designs require careful modeling to manage interactions between elements. For instance, the 6-meter elements in one project had to be scaled for a different frequency to perform optimally, and the radiation patterns for each band can vary significantly depending on the antenna's height above ground.
For decades, the gold standard has been the free utility by A.C. Legere (AC5EK) called the or online calculators like k7mem.com . You input your desired frequency (e.g., 14.150 MHz), wire diameter, and it outputs:
Developed by Les Moxon (G6XN), the Moxon antenna is a modified two-element parasitic array. It consists of a driven element and a reflector, characterized by rectangular shape and folded tips.
Wire nesting techniques to build a single antenna structure that works across multiple HF bands (e.g., 20m/15m/10m) using a single feedline. : Though the "Moxon Rectangle" is synonymous with
To build a Moxon antenna, you'll need the following materials:
Finding a High-Frequency (HF) antenna that performs exceptionally well across diverse environments is a primary challenge for amateur radio operators. Space restrictions, local noise, and transport limitations often force operators to compromise on signal strength or bandwidth.
The Moxon design offers distinct performance traits that make it highly effective for HF communication:
Hence the phrase “for all locations” — from crowded urban homes to remote summits.
While Moxon himself primarily wrote about the VK2ABQ antenna and wire-beam variations, his refinements led to what we now call the "Moxon Rectangle"—a two-element parasitic array with ends folded toward each other. Technical Breakthroughs