Wednesday, 5 November 2014

SuperYagi 10/11m Moxon Antenna Review

Wikipedia describes the Moxon antenna as a simple two element parasitic array antenna, popular with Amateur radio enthusiasts for its simplicity of construction. The design is rectangular, with roughly half the rectangle being the driven element and the other half being the reflector. It can by thought of as a Yagi antenna with bent elements and without directors. The invention is credited to Les Moxon, G6XN.

For a couple of weeks I've had a 10/11m Moxon from SuperYagi on my 20' test pole.

The antenna came with the elements pre-configured for the amateur 10m band, and had a 1:1 SWR at 28.300 Mhz

A simple adjustment mechanism allowed me to configure the aerial for the 11m band, extending each element by approximately 3" in both directions. Once adjusted the SWR was 1:1 at 27.500 Mhz with more than enough bandwidth to cover all of 11m and up.

The antenna is designed to use a 50 ohm direct connection ensuring all power is delivered to the antenna, unlike other designs which use a lossy Gamma match.

The boom to mast brackets supplied with the antenna were too small to fit my 2" scaffolding pole, but Kevin at SuperYagi quickly shipped a larger fixing bracket out to me.

Here it is along with my 2m colinear for scale.

Once configured for 11m, I successfully worked a number of US states, including Washington on the west coast, along with the West Indies and South America. I'm blocked at 20' height to 90 degrees of the compass, but once the antenna is transferred to my main tower I'm sure I'll be able to work in all directions, the gain also improves the higher you can raise the antenna above the ground.

There obviously isn't as much forward gain as a 3-element Yagi, but where this antenna really scores is its ability to shut the back door to unwanted stations as a result of its excellent front to back ratio.
I have noticed the noise level is much lower in comparison to my Imax 2000 Vertical, allowing me to hear weak stations that would have been lost in noise.
Now something which is unique to SuperYagi, all of Kevin's antennas are very easy to upgrade, he tells me it is possible to add extra elements without any waste.

All-in-all I'm really pleased with this antenna, being hand built the quality is very good, and I've had excellent support throughout the project from Kevin at SuperYagi.