[TowerTalk] 15 meter yagi height for 6000 miles

[Bob K6UJ]

Has anyone used the HFTA program and can tell me the best height for a 15 meter yagi for 6000 miles.
Assuming there aren't any hills obscuring the take off angle.

The carribean is about 6000 miles from my qth and from experimenting I have noticed that lowering the beam 
down from 90 feet down to 50 feet it is markedly better for 15 meters.

I just bought the new antenna handbook and plan to dive in and learn how to do the HFTA myself but was
hoping someone else had an idea of the best take off angle angle for 6000 miles on 15.
I believe 50 feet is about 3/4 wavelength high and gives me a 20 degree takeoff angle on 15.  
Hope this all makes sense, hihi.

Bob
K6UJ