[TowerTalk] The Value of HFTA

[jimlux]

On 1/21/19 11:33 AM, Jim Brown wrote:
> On 1/21/2019 11:23 AM, Edward Sawyer wrote:
>> One thing that HFTA does NOT do well is answer the question about 
>> stacking
>> from a "max gain" perspective.  EZNEC will tell you the best design for
>> stacking yagis for max gain in a direction however HFTA will tell you 
>> what
>> the right height for those yagis are or if the stack is even the 
>> strongest
>> signal under typical approach angles.
> 
> Right. HFTA models the performance of individual dipoles used alone, not 
> in combination. When you select a Yagi, it simply adds gain.
> 

Correct me if I'm wrong, but I think it also changes the effective 
vertical beamwidth of the point source radiator (in proportion to gain 
or sqrt(gain) or some rule).  that is a 2.15 dBi dipole has a vertical 
pattern that is uniform gain, but a 10 dBi Yagi has a vertical pattern 
with some significantly smaller vertical height.