[TowerTalk] 80 Meter Delta Loop

[Jim Brown]

On 7/24/2024 11:31 AM, kq2m at kq2m.com wrote:
> One antenna that does work well even over poor ground is a 4-square with 
> elevated radials, preferably above .05 wavelength in height.

Poor soil degrades the efficiency of vertically polarized antennas both 
under the antenna AND in the far field, where the ground reflection that 
reinforces the direct wave is created. Radial systems affect ONLY what 
happens under the radials -- they screen the direct field of the antenna 
from the lossy earth, and give the antenna a low resistance path for its 
return current. That's ALL that they do. They cannot compensate for 
lossy ground in the far field.

But ground characteristics DO vary with location, even with lousy ground 
under the antenna, good ground in the far field can support the needed 
reflection, making the antenna work well. That's the classic case of a 
vertical near salt water. And N6BT, well-known for his "Team Vertical" 
setups, has recently done field measurements with a drone to show that a 
vertical very close to a drop-off (his testing was on a mesa in AZ) 
produces a very strong signal in the direction of the dropoff. He first 
showed this work as part of the Pacificon Antenna Forum about five years 
ago, to which we both often contributed.

73, Jim K9YC