Bob,

Since the height above ground varies due to the elliptical nature of orbits the max range also varies. Where the two stations are located relative to the apogee of the orbit can also come into play. If you are on the wrong side of the earth when the satellite is at its apogee that could be a problem. Here is my best shot at the range of max distances for AO-07 - compare them to numbers you get from other folks and let me know what you find. My numbers could be and are probably wrong.

http://www.tomdoyle.org/ao-07.png

73 W9KE tom...