[TowerTalk] trees and verticals

[Jim Lux]

On 12/28/11 11:21 AM, David Gilbert wrote:
>
>
> All true.  I'm not even sure at this point, but I think the original
> message that began this thread discussed a vertical wire running
> alongside and in close proximity to a tree trunk, which would of course
> put the potentially lossy medium within a high intensity portion of the
> EM field and therefore have a greater impact.


Exactly.. and a scenario that is actually fairly easy to model with NEC. 
  Just put a resistively loaded wire of appropriate properties next to 
the antenna and see how much current is in it.

Let's say the tree is 5 mS/m (200 ohm meters) and it's 30cm diameter.. 
that's 0.07 square meters.

so 200/0.07 = 2.86 kOhm/meter length for the wire tree.  One could make 
a "cage" of wires, say 4 of them in parallel at 11.4kOhm/meter loading, 
so that the pattern is a bit more "realistic"