[TowerTalk] Ledge Lightning Ground Advice

[David Merchant]

Guys,

 

I could use some advice.  Late last fall, I erected 40' of Rohn 25G with a
Tilt-over base.  It sits on top of a ledge that only has about 2-3 feet of
rocky topsoil.  When I dug the hole for the foundation, I excavated all the
loose fill and I core-drilled the rock below about 36".  I then epoxied
4-pieces of rebar in the holes, and poured about 3-1/2 yards of concrete
with anchor bolts for the base plate.  Unfortunately, I didn't think to bond
any of the rebar or anchor bolts.

 

Right now, the only grounding the tower has is a connection to a 2-ga ground
wire that runs 120' underground with the conduit that feeds the power.  It's
in-turn mechanically connected to a 2-4' ground rod (the max I could
install) every 15'.  The 2-ga wire is also connected to the Single-Point
Ground  where the coax enters the home.

 

Since lightning season is about to get started, I'm concerned that this is
insufficient grounding.  

 

I was considering bonding some 2-4" copper strap to each of the tower legs
and running it along the ground for 50' or so.  Also, I do have a SteppIR
BigIR vertical about 20-feet away that has an extensive ground plane, albeit
with insulated 12-14-ga wires.  This could be bonded as well, but currently
isn't.  

 

What would you guys recommend I do to augment the existing ground?

 

73,

 

Dave

K1DLM