A Imax 2000 or any 5/8 wave antenna one wave length above the ground yields the avails the lowest angle of radiation to the horizon.

It also optimizes DX:

**Antennas Elevation Angle in Degrees**
Vertical

1/4 wavelength long 28 (15 - 40)

3/8 wavelength long 23 (12 - 35)

1/2 wavelength long 18 (09 - 25)

5/8 wavelength long 12 (07 - 18)

Hortizontal Dipole

1/8 wavelength long above ground 90 (55 for lower 3db point)

1/4 wavelength long above ground 60 (38 - 82)

1/2 wavelength long above ground 30 (18 - 40)

3/4 wavelength long above ground 21 (14 - 28)

One wavelength long above ground 17 (09 - 19)

Hortizontal Yagi

1/4 wavelength long above ground 43 (32 - 54)

1/2 wavelength long above ground 30 (18 - 38)

3/4 wavelength long above ground 21 (13 - 28)

One wavelength long above ground 17 (09 - 18)

From:

Antenna height vs skip angles