A tale of lightning and ham radio

Flash mark on inside of door from exit discharge

Flash mark on inside of door from exit discharge

Some people enjoy the sound of summer thunderstorms. And some people hear thunder and recognize it denotes danger from lightning. Lightning is of paramount concern to amateur radio operators.

This past July, one such amateur radio operator in the Mason County Amateur Radio Club was visiting friends when a summer storm blew in.

The distant peals of thunder came from the northwest over the Olympic Mountains as Ray headed for home.

Ray saw the prevailing wind was from the west, and recognized the storm was blowing toward his location. He took steps to isolate his radio gear and other electronic equipment.

Having isolated his gear, he relaxed with coffee and a book, all the while listening for thunder. Using five-seconds-to-a-mile method of estimating distance, Ray judged the lightning was occurring three to four miles distant.

Then a lightning strike occurred about a mile away. Moments later, another strike hit a cedar tree 100 feet east of the house. The lightning entered the tree about three feet from the top and exited about five feet above the ground, leaping to a metal stock gate and exiting through a screw-in hinge attached to the stable. It then jumped into the electrical service panel for the horse barn, partially blowing a full-size plywood panel from the north wall of the tack room.

But that wasn’t all that happened. When the lightning reached the metal stock gate, it also entered the electric fencing surround about 2.5 acres. The high-voltage surge circuited the fence and destroyed the motor in a remote gate opener.

Continuing on, it entered the garage from the ground rod of the electric fence, blowing several pieces off of the electric fence charger as it passed through. In the garage, a GFI outlet was damaged, and our intrepid radio operator had to replace a couple of breakers and the fence charger.

Amazingly, no ham radio equipment or computers were damaged. The electrical ground of the radio station apparently worked to shunt excess current to ground.

But that’s still not the whole story. A small barn along the driveway is used as the base for feeding livestock in the winter. It has minimal lights and outlets, but these are usually used only from November to March for early and late lighting and for freeze protection. When Ray went to turn the breakers on in the feed barn, they did not work. These pictures tell the story. It should be noted that the barn was full to the rafters with dry hay during the July storm.

There are several lessons in this incident for amateur radio operators:

  • provide a good electrical ground for your ham radio equipment
  • disconnect your sensitive electronics when you hear thunder
  • if a lightning strike occurs nearby, inspect equipment and lines after the storm has passed
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