Topband: Radial length

Jim Brown jim at
Wed Oct 4 00:32:06 EDT 2006

On Tue, 3 Oct 2006 16:48:11 -0500, Mike(W5UC) & Kathy(K5MWH) wrote:

>However, what happens if there
>are, say 4, very long radials among a much larger number of radials of
>moderate length.  Should I go whack off the very long radials and utilize
>the wire elsewhere as shorter radials?

Of course not. Long radials do not detract from the performance of shorter 
ones. Rudys work simply shows that for a given quantity of wire in the 
radial system, you get more bang for your buck near the tower. 

But the fundamental thing that is going on (per the references) is that RF 
current is greatest near the antenna, and falls off as you move away from the 
antenna. Thus, having a high density of radials NEAR the antenna is more 
important than ONLY having a few long ones. It isnt either-or, rather, put 
your first priority on a high density of radials near the antenna. 

One of Rudys observations is that if you have ONLY a few long radials but 
not that high density of radials neer the antenna, the current never finds 
its way to the end of the long radials because it is dissipated in the earth 
near the antenna. 


Jim Brown K9YC

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