[TowerTalk] Ground Radials Insulated or Not

[Gary Schafer]

This thing is getting long and drifting off the subject of radials.

Just a few notes on the other stuff:

When I say don't pay too much attention to the NEC codes I am talking 
about what is and is not effective for the subject at hand.

Saturation:
When the ground tries to absorb a large amount of energy via a lightning 
rod there are eddy currents that are set up in the ground. That 
increases the inductance and the impedance.
When in the ground the energy wave travels much slower than it does in air.

Current carrying capacity of rods:
The current carrying capacity of ground rods for a safety ground is 
irrelevant when discussing lightning.

Quality of lightning ground:
A lightning ground that is "good enough to keep a building from burning 
down" is not what we are talking about here.
A good lightning ground is one in which equipment is not damaged during 
a strike. That takes a little more than a "minimum requirement ground".

Voltage gradient:
Voltage differences do occur at different points on the ground due to 
the resistance of the soil. They also occur because of time delays in 
the travel of the energy being dissipated in the earth.

Oxides:
The point that I was trying to make about corroded wires or ground rods 
was that even if they are corroded they still are very good conductors 
in the ground because the ground is moist. Even a rusty iron rod where 
the surface would be a poor conductor in air is still an excellent 
conductor in the ground. Especially when you compare the ground 
resistance to that of the rod.

73
Gary  K4FMX