[TowerTalk] Ground Mounted vs. Elevated 4-squares and their radials

["Bob Shohet, KQ2M" <kq2m@kq2m.com>]

Hi,

I have several ground-mounted vs. elevated radial questions for 4-squares.....

Let’s say that an elevated 4-square has 4 vertical elements (each with 4 
elevated radials) in the following configuration:


N 
O  
R
T
H

L1                                  L2

L                                              L
E                                             E
D                                             D
G                                             G
E                                             E

L4                                  L3


S
O
U
T
H


Normally one would assume that the radials are reasonably horizontal.  However, 
in THIS situation, let’s say that “L1” has two elevated radials that are NOT 
horizontal but rather significantly sloping up to a point ~20 feet higher.

1)  Does the slope up of the radials affect the effective radiation and 
reception angles?  If so, then in what way?  Since L1 is fed as the NW leg in a 
Comtek relay box, which direction(s) would be affected?   My understanding is 
that when the NW position is selected on the Comtek control box, L2 and L4 
radiate towards L1.

2) Now instead of an elevated 4-square with elevated radials, let’s say that we 
are using ground-mounted 4-square with 30 ground-mounted radials per leg in the 
same configuration as in #1.  If the radials from L1 are sloping up at say a 30 
degree angle (because of 15 foot tall ledge in front of it), how does that 
affect the radiation and reception angles?  If there is an effect, would it be 
a better idea to avoid running any ground-mounted radials  on the Western side 
of L1 (to avoid the ledge) and just run the radials from North around to South? 
 Would not having radials from North to South (on the Western side) affect the 
pattern or would that 180 degree span without radials be ok?

3) Let’s say that it is decided that it is better to continue to use the 
elevated element configuration but instead of using elevated radials it is 
determined that it is best to use 30 ground-mounted radials per element.  Can I 
simply run a copper wire connecting the shield of the coax connector at the 
feedpoint of the elevated radial, to the ground?  ( I would use some form of 
copper ring and solder each of the ground mounted radials to the copper ring).

Thanks for your thoughts and help!

73

Bob KQ2M










Bob Shohet, KQ2M
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