Bob W7LRD

I came across this info, might be of some value.

Ref: The Satellite Experimenters Handbook, Pg 9-6

Max Dist (range) = 2R * arcos [R/(R+h)]

Where R = 6,371 km and h = 1,459 km at Apogee (AO-7) h = 1,440 km at Perigee (AO-7)

Therefore the maximum possible communication distance via AO-7 at Apogee = 7,904 km. Therefore the maximum possible communication distance via AO-7 at Perigee = 7,861 km.

The difference in range from apogee to perigee appears to be only 33 km.

73, Pierre ZS6BB