HomeBrewed 2 Meter Single Side Band 9 Element Yagi

April 28, 2019

So I decided that I wanted to do some SSB work using my old Kenwood TS-700SP. The radio is an all mode transceiver that puts out 10W only. I want to get a VHF amp to get my power to somewhere around 100W. Later I will describe how I accomplished that but for now I'll focus on the Yagi.

I used VK5DJ's antenna calculator that can be found here: http://www.vk5dj.com/yagi.html
Then I graphed the antenna using EZNEC that can be found here: https://www.eznec.com/

After I used the calculator to give me all of the measurements I designed the cross members for the antenna and used my 3D printer to make them. I also designed end caps to keep the elements water tight.

Here is a close up of one of the cross sections:

I mounts the 3D printed parts to the boom. I use a boom that is 1-3/4" in diameter and roughly 14' long.

The antenna elements were recycled from a Mosley antenna that was bent up. I cut the straight sections and was lucky that I had enough.

The driven element is where I made my first mistake. I didn't realize that the leads from the SO239 connector would be seen as the elements. Below is how to never connect your feed line to your antenna.

You want to keep the leads from the coax as short as possible. This looked MUCH better on the antenna analyzer:

This Yagi has roughly 13.3db of gain, with 120w in, that is roughly 2500w ERP. Yay!
After I finished the Yagi, I coated the end caps and the coax connections with UV resistant clear liquid tape. Later I will install it on top of a 35' tower with an antenna rotator. Below is a graph of the antenna using EZNEC.