Floyd Davidson wrote:
"Suggesting your designs have never collided with such an anomaly just
means you didn`t do many or you`re failing to recall them."

It means care was taken in path planning. Microwave propagation is very
predictable. The only variable is the atmosphere and long statistical
records are available which allow a design for a percent reliability,
99.99 out to the limit of your budget.

Of course, on any particular path, there will be fades on some foggy
morning, but that doesn`t guarantee failure if you`ve planned for it.
The phone company uses alternate routing. I`ve designed similar systems.

What I said was, the as-built hops performed as designed during normal
propagation. That`s nearly all of the time. The received carrier power
measures remarkably close to the predicted value nearly every time and
if it doesn`t when the the alignment is complete, in my experience, it
has been always due to a defect in the system, not in its design..

I have never had to go back and "beef up" a hop to obtain reliability,
and I`ve put some hops in tough territory. The arithmetic is simple and
so are the criteria.

Best regards, Richard Harrison, KB5WZI