[TowerTalk] [CQ-Contest] Stacking on separate towers, take off angles?

[Jim Brown]

On 3/15/2013 8:19 PM, David Gilbert wrote:
> No way that the respective wavefronts will add in all of those 
> directions.  Geometry alone would tell you they are much more likely 
> to cancel in some directions. 

Right. MANY directional arrays are the result of wavefronts from 
multiple driven elements that add algebraically (magnitude and phase) 
differently in different directions and elevation angles. Magnitude and 
phase of any antenna varies with both horizontal and vertical angle, and 
antennas will have some magnitude and phase relationships to each other 
based on their  spatial relationships.

Yes, we can drive two or three Yagis pointed in the same or different 
directions, but HOW they combine to form a pattern can be as close to 
the infinite number of monkeys and typewriters as it is to how the 
operator thinks he is aiming them.

73, Jim K9YC