Direct lighting strikes are one of an amateur radio operators primary fears. When I first constructed my station I simply unplugged all of my coax lines from the radios when a storm was approaching or if I knew bad weather was coming in the next few days while away for work. This last summer I spent a considerable amount of time getting my station more “lightning ready.”
For the coax lines, I used Polyphaser lighting surge protectors. These are a common tool employed by many operators. In a nut shell, these devices direct the surge during a strike to the ground, instead of continuing its path to the radio.
The Polyphasers are mounted on a plate of aluminum, which is then hard lined to 8 gauge copper wires that run to three different ground rods located at the bottom on the antenna mast. Some of you that are familiar with them may be wondering about the two larger ones. These are specialty items that Polyphaser built for railroads to use in locomotives and are equipped with pass filters. I was able to locate them on eBay for a very reasonable price. I have a couple of dedicated radios (railroad radio monitoring and EchoLink on UHF) that fall into the pass of them, so it was a win win when I was able to get them for a reasonable price.
Now that the coax was protected I need to find a way to protect the antenna rotator control wires. After some research I decided to build a circuit using Metal Oxide Varistors (MOVs). The MOV is a reasonable solution, and act as a “weak dam” of sorts for electrical current. As voltage rises, their resistance reduces. The ones I purchased are rated for 130V and as my control wires carry a maximum of 32VAC, they are well suited for the job.
I need to make the whole setup weather resistant, so I purchased a PVC junction box from my local hardware store and began the task of mounting a terminal block inside of it. I then installed some connectors to the control wires and test fit it.
The next step was to get the MOVs ready to be wired in parallel between the control lines.
And install into the box….and out to the mast.
In reality the lighting may blow the whole damn thing apart if there is a direct hit. But, it gives me a bit of piece of mind for the time being.
Thanks for reading.
Always was worried about my grounding whenever thunder began to roll…. Great article, Will!