The Moxon is an 2 element Yagi style antenna that boasts of a low takeoff angle and high front/back signal to noise ratio. The 15 meter Black Widow Moxon is an excellent antenna for Field Day or other events were a lightweight, portable antenna is ideal. Follow along as I build a Moxon antenna out of fishing poles and other common parts.
My feelings are that 15 meters is going to be the strong band for this year’s ARRL Field Day and I wanted an antenna that could really exploit the band’s capability. Living in the Upper Midwest, using a directional antenna will greatly enhance my signal as I aim it towards either the east or west coast. So let’s discuss what a Moxon antenna is and then I’ll show you how to build your own 15 meter Black Widow antenna.
The Moxon is named after its creator Les Moxon, G6XN. It is best described as a rectangular two element Yagi antenna. I said rectangular as the ends of the driven element and the reflector are folded inwards, which reduces the amount of space it occupies, about 70% of the space of an equivalent dipole antenna. If you add lightweight spanners to the rectangle, you can rotate the antenna.
Typically, the Moxon has about 2db of forward gain, but it also exhibits a high front to back ratio of up to 9dB, depending on height and band. Moxons are easy to build and highly effective on 6 and 2 meters, I’ve previously built a 6 meter Moxon and have the plans on my website, links are in the video description below, but today I’m going to take it a step further and build a 15 meter Moxon.
As a side note, if you are looking to build a Moxon antenna for 10, 12 or 17 meters, this tutorial will be helpful in that regard and you can adapt the wire lengths and support methods for those bands.
The inspiration for this antenna build came from an article in the May 2003 issue of QST Magazine by Allen Baker, KG4JJH titled: The Black Widow- A Portable 15 Meter Beam. The article and full plans are available on his website with a link in the video description. With the plans being 20 years old, I had to make a few modifications to the construction as some of the parts had changed, namely the fiberglass collapsible fishing poles. I’ve also made a large deviation by 3D printing the hub instead of building it out of wood. This makes the project a bit more approachable if you don’t have a wood shop but have access to a 3D printer. All of my 3D printed parts are available on Thingaverse if you want to tackle this project yourself.
— References —
KG4JJH Black Widow 15 Meter Moxon Antenna: http://www.kg4jjh.com/blackwidow.html
AC6LA Moxgen Calculator: https://ac6la.com/moxgen1.html
Building the 6 meter Moxon Antenna: https://www.jpole-antenna.com/2014/06/11/building-the-6-meter-moxon-antenna/
— Parts list —
10′ Black Widow Fiberglass Fishing Pole (B&M BW3RR) https://www.walmart.com/ip/10-Black-Widow-Ready-Rig-Telescopic-Panfish-Pole-by-B-n-M-Pole-Company/15908257
Black Widow 15 meter Moxon Center Hub: https://www.thingiverse.com/thing:6074743
SO-239 chassis connector
50 feet wire approximately (I used 14 ga)
⅝ inch dowel, 48 inches
½ inch CPVC
6 x ½ inch machine screws, nuts, and washers
4 #10 eye hooks
Assorted Ring Terminals
Painters pole: 15 – 23 feet
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