homebrew antenna analyzer

A while back, I threw together a quick 40 meter dipole out 75 ohm rg-6 and some AC wire. I’ve mostly been using it with my receivers. So far it seems to work okay, but I have really had nothing to compare it to.

I looked into purchasing an antenna analyzer and like everything else with ham radio, they seemed unusually expensive. Being a newcomer to the radio world, I was surprised to find radio equipment so expensive. Some people I have spoken to have thought the same where others say prices are quite reasonable. I guess I have been spoiled by cheap digital devices from China that cost a few dollars and pack in the features.

During my research, I ran across K6BEZ’s homebrew antenna analyzer.

I followed the schematic exactly and put it together on some perfboard.

I used the processing sketch on linux to view the results. Here is a plot of my dummy load.

And here is the plot of the dipole.

As you can see, this dipole really needs some work. Since I put it together with scraps, I will most likely take it down and build a new dipole. I will most likely try a multiband 20m/40m dipole.

From what I have read, the antenna analyzer’s VSWR measurements aren’t quite accurate and the analyzer could do with some amplification of the DDS signal. Once I get the new antenna put together, I will add an amp and test the new antenna and compare the results with a few different SWR meters to check the accuracy, but for now, I am happy with how the build turned out.