[TowerTalk] 4-Square Configurations

[Ralph Fedor]

I returned from a weekend away and found the interesting 4-square, radial, 
and counterpoise discussion on the reflector.

I've accumulated the materials for an 80 meter 4-square installation.  Full 
quarter wave wires will serve as vertical radiators and drop from catenary 
lines off my tower.  I have the choice of bringing the vertical wires all 
the way to ground level and placing radials on the ground for each vertical 
element -- OR -- bringing each vertical element down to 12 feet above 
ground and utilizing elevated radials and a ground screen.

An interesting argument for the elevated radial / ground screen 
configuration is in ON4UN's book.  The vertical radiators are cut for SSB 
and a stub is switched in and out of the SINGLE elevated radial beneath 
each vertical radiator.  The shorted stubs resonate the system at 3775; 
with the stubs unshorted, the system resonates at 3525.  John, ON4UN, 
states there is some high angle radiation introduced when using this 
configuration.  In Europe, however, this is not so disadvantageous.  Also, 
I've heard/worked John on 80 and his signal seems just fine in the midwest 
on CW and SSB.

The ground screen I have in mind would be 120 wires on the ground radiating 
from my tower base and extending out for 120 feet.  Wires in the ground 
screen would therefore extend 1/4 wavelength (3.5 MHz) peripheral to each 
vertical radiator.

  I only want to do this installation once.  The ability to easily switch 
from CW to SSB is very appealing and this seems to be the big advantage of 
the SINGLE elevated radial / ground screen system.  I really like CW, but 
there's DX on SSB too.  If anyone has previously thought this through, or 
if there is a compelling arguement for a midwesterner not to use the single 
elevated radial / ground screen system and instead use the conventional 
on-ground radials for each vertical element, I'd enjoy hearing more about it.

Thanks in advance for any comments.

73 -
Ralph - K0IR


  

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