And to complicate matters further the max antenna height being talked
about being around 3-4 wavelengths off the ground is going to break the
radiation pattern up into a number of lobes at various vertical angles.

For that reason alone I think it is still worth modelling. There will be
specific heights where the horizontal radiated component is at a maximum
and this is likely the most desirable. It will also give a good
indication of what takeoff angles will be like for ionospheric
propagation modes. You'd also see the spacing/height effect on
undesirable straight upwards radiation.

Then again a crank up/down tower and maybe inter element spacing
adjustment mght be a good empirical way to get the right data as well.

Bob VK2YQA

wrote:

Real simple. He's so close to the ground he has a lot of high angle
gain. As he goes up that will go down and the low angle gain will
improve.