All lightning is weird and unpredictable. There are countless stories
of lightning hitting something on the ground while missing a nearby
pole, tower, building, or tree.
73,
Dave AB7E
On 10/1/2021 12:32 PM, Ignacy Misztal wrote:
My QTH has two sets of antennas. A 100 ft tower with phased beams at 100
and 60 ft, also supporting 4 sq for 80 and shunt fed for 160m. Some 120ft
apart, a Spiderbeam on a 45 ft aluminum Spiderpole and rotated by G-800DXA.
Recently the rotator for the Spiderbeam stopped working. There is no DC
output from the controller but the position indicator is OK. With
external DC the rotor works. About 30 ft from the Spiderpole, a 60 ft high
sweetgum tree exploded vertically. But an 80ft pine tree embracing the
sweetgum is fine.
Apparently the lightning hit the sweetgum and induced enough current to
partly blow the Yaesu controller.
A few questions to the knowledgeable.
Why the smaller tree was hit and the bigger is fine? Why other trees up to
100 ft are OK? Why the 100ft tower shows no damage? Is the Yaesu controller
vulnerable to lightning hits? Is it worth repairing?
The tower is well grounded and the antennas by the house are bonded. The
Spiderbeam rested on 4 ft metal poles and was not grounded otherwise
Ignacy, NO9E
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