[TowerTalk] 40 meter interaction

[Tom Rauch]

Hi Jay,

> Good points, I had one private email with another gentleman that I
> pointed out the near field will not have the cancellation that occures in
> the far field from radials, and raised radials are the worst case.

I still remember walking under a raised radial (thirty feet high) at a 
ten kW BC station with a hunk of wire tied in my belt-loop of my 
blue-jeans.

No matter how carefully balanced the radial system is the fields in, 
under, above and around elevated radials are a large fraction of the 
field radiated by the radiator.

The wire arced through my jeans as a reminder of that!
 
> Your point of the dipole affecting the vertical array's pattern is right
> on.  I think if the feeline and the array can be detuned the affects work
> both ways. In other words, if the vertical doesn't couple to the dipole
> also means the dipole doesn't couple to the vertical. 

I'd opt for three feedline chokes with one at the antenna, one half 
way down  the feedline, and one at the ground....all high 
impedance. 
 
> I still think Tom should try it, then we all can learn how well it
> worked or how badly it works. 

I'm sure it will work. It just helps to know what to expect, or have a 
feel for what the problems might be. Knowing how it works is most 
of the fun.

They key to it being useful to everyone is having a repeatable 
logical solution, since anyone can make one of something work 
with enough random fiddling.
73, Tom W8JI
w8ji@contesting.com

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