[TowerTalk] Clamp on ground resistance meter

[Jim Brown]

On 10/6/2019 9:45 AM, Grant Saviers wrote:
> Approximately.  The meter is measuring the sampled leg against the 
> parallel resistance of the other two legs (if there is no other 
> connection).  So if the reference parallel resistance is low then the 
> error for the measured leg is low. (but always positive)

An over-simplification, because there is mutual inductive coupling 
between nearby rods. All the instruments I've seen for this purpose work 
at power or audio frequency, but lightning is an RF event! IEEE data 
I've seen says that the energy has a very broad peak (+/- a decade of 
frequency) in the AM broadcast band. I'm sure Jim Lux can provide more 
definitive data on this.

73, Jim K9YC