[TowerTalk] 80 meter vertical

[Jim Brown]

On 1/19/2019 6:58 PM, john at kk9a.com wrote:
> That is a great question, I have wondered this many times when operating on
> the sloping terrain in VP2V and KP2.

N6BT, original designer of Force 12 antennas, regularly speaks at the 
Pacificon Antenna Forum. Several years ago, he presented some very 
interesting work he had done on exactly this topic. He found a test 
range (in SE AZ) on a sort of mesa, with dropoffs in all directions. His 
test antenna was a vertical that is, in essence, a loaded dipole, so it 
needs no radials. He found that propagation was greatly enhanced in the 
direction of a drop-off when the antenna was at the edge of the drop-off.

At the edge of a drop-off to SA he worked SA but no JA. At the edge of 
the drop-off to JA he worked JA but no SA.  In the middle of the mesa, 
he worked neither. He also looked at vertical patterns with a drone, and 
found that radiated field strength extended below the plane of the mesa!

73, Jim K9YC