Topband: Best wire antenna for roof top location

Jim Brown jim at audiosystemsgroup.com
Tue Aug 11 04:00:00 EDT 2015


Ah, perfection. Sadly, EZNEC does not provide that set of options. If I 
could build that model, I would. But I can't.  I will take this first 
approximation, understanding its limitations.  Brown's 99th law -- never 
let perfect be the enemy of good.  We don't know the nature of that 
roof, so modeling several possibilities and using the result to TRY 
things seems like a pretty good approach to me.

73, Jim K9YC

On Tue,8/11/2015 12:42 AM, Guy Olinger K2AV wrote:
> In order to estimate your hypothesis you need to create a building 
> shaped cage of dielectric wrapped, resistively loaded, interconnected 
> wires. It is necessary to bookkeep in the model that the roof, as 
> conductor, is connected to a vertical conducting face on four sides 
> and then to ground.
>
> These faces electrically are at least in the quarter to half 
> wavelength range vertically and can radically effect the appearance of 
> the roof as conductor. These faces can have significant radiation. 
> These faces can be the majority radiator with the dipole serving 
> mainly as a matching device to the building as majority radiator.



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