[TowerTalk] 15 meter yagi height for 6000 miles

Frank frankkamp at att.net
Fri Mar 2 15:50:55 PST 2012

Pete Smith N4ZR wrote:

>Frank, all that any good current book on antenna design will do is refer 
>you back to the same propagation realities that are used by HFTA and 
>other modeling software.  HFTA produces nomograms that show what the 
>best takeoff angle will be for a particular target area, as share of 100 
>percent.  Those are then matched with the antenna patterns generated 
>over real ground profiles, and a figure of merit is produced that tells 
>you, on *average*, how well a given antenna system at your QTH will 
>perform relative to the target area.  Of course, conditions will vary 
>from day to day, or year to year, that is exactly what you want to 
>know.  It doesn't absolve you from the need to design and build a good 
>antenna, but even the best antenna will be (on average) inferior if 
>placed at the wrong height.
>73, Pete N4ZR
Thanks for the explanation, Pete.

I guess I did not fully understand what HFTA was all about.

Now that I do, I am not convinced it is entirely useful, at least not to 
me since I don't have the resources to raise or lower my antennas at 
will.  I just raise them up to 1/4 wavelength at the lowest  frequency 
of interest and hope for the best.

So far that has worked for me.

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