Floyd Davidson wrote:
"---I`ll bet you just exagerated a little, that`s all."

Too many hours of daylight on Floyd are taking their toll.

Everything you work with is known. precisely, including path attenuation
under normal propagation conditions. Normally, you don`t have a path
grazing at a highly reflective point. Your path survey discloses path
detractions and you adjust for the possibility of distructive
interference. You may opt for a high / low antenna placement for the
path ends, diversity, more clearance, shorter paths, and brute-force
fade margins. The high / low option lets you move the reflection point
and the reflection. Long microwave systems must have huge fade margins
anyway due to noise buildup from individual path contributions. A
receiver not too much below the overload signal point is a very quiet
receiver and contributes almost no noise to a system.

When the path design is right, the as-built numbers are almost exactly
as calculated, whether you believe it or not.

Best regards, Richard Harrison, KB5WZI