Moxon antenna calculator

Posted by Fred C (W6BSD) on May 07 2022

Leslie Moxon, G6XN, invented a two-element in the 1950es, named after him. Less Moxon published an article in a QST magazine issue from 1952 titled Two-Element Driven Arrays describing his antenna. Since then, the Moxon antenna has been referenced several times in the QST magazine.123

The Moxon antenna is electrically equivalent to a two elements yagi. Because each element's end is folded, the antenna is 70% more compact than its full-size yagi equivalent. The Moxon antenna is a monoband directional antenna with a wide lobe in the front giving a 2.0dB gain and the null on the back. For example, the front-to-back ratio is above 9dB on the 10-meter band.

The antenna can be constructed with copper or aluminum tubing or electrical wires with spreaders made of wood, old fishing rods, or PVC pipes. Building this antenna can be a fun weekend project.

The Moxon antenna is lightweight and can be mounted on a light TV antenna mast on the house chimney or a push-up telescopic mast. An inexpensive TV rotator or an arm-strong4 rotator will work without issues.

Moxon Rectangle Calculator

 Frequency: MHz Wire diameter: mm Wire size in: Millimiter AWG

Antenna

I spent part of a weekend building this 6 meters antenna to test meteor scatter. The center junction is a piece of PVC piping. The spreaders consist of four fiberglass snow driveway markers attached to the center hub with a plexiglass plate. I used a stranded wire, gauge 16, readily found in any hardware store, for the driving and reflecting elements of the antenna.

The modeling of this antenna gives me a front-to-back ratio of 12.3dB.

My RigExpert antenna analyzer shows an SWR below 1.5:1 from 50.08MHz to 51.8MHz and less than 2.4:1 on the entire 6-meter band.

You can see more antennae built by amateurs radio worldwide on the Monxon Antenna Project website.

1. May 2003 QST The Black - Widow A Portable 15 Meter Beam

2. April 2004 QST A Six Meter Moxon Antenna

3. April 2009 QST A 20 Meter Moxon Antenna

4. October 2011 Moxon Mighty Mite

5. Rotated by hand