Topband: Ground Screen Question

k3ky at k3ky at
Mon Jan 11 09:47:50 EST 2016

Hi, Bob-

I wouldn't risk this, personally, for the small benefit that might be
gained. Consider- if your tower ever takes a direct lightning hit,
nearby ground currents can be very high indeed. There are some cases
documented where concrete fractured or even exploded as a result of
these violent internal currents. Even many decades old, it still has
some internal moisture content. During the pulse, it flashes to steam.
That energy has to go somewhere. The same thing happens when lightning
shatters a tree- due to the high current density, the internal sap
flashes to steam and the tree literally explodes. If I were looking
at this problem, I'd be asking myself "how can I encourage the pulse
of current to spread out alongside and parallel to the driveway?"

Our neighbors took a direct hit to their roof a few decades back-
some recently planted shrubs next to the underground transformer in
their front yard literally exploded out of the ground and landed some
15+ feet away in the street out front. I would never underestimate
the potential for mayhem when it comes to lightning.

73, David K3KY


I searched the archives under "ground screen" and could not find info on
my situation.
I have a 15 foot by 70 foot, 6 inch thick concrete parking slab along
side our house. My tower
is about 15 feet away from the side of the slab. I am planning radials
to extend out from the tower which
I will be shunt feeding for 160M and remembered that the slab has
welded wire mesh reinforcement
at mid depth. The welded mesh is 6 in by 6 in and # 8 wire. Would the
mesh be a good ground screen ?
I will have to drill and connect to the mesh at various places but would
be worth it if a good ground screen.


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