Floyd Davidson wrote:
"Richard you can cut the bull**** out."

Floyd claims to have measured microwave paths for 40 years. I`ve been
doing it since 1960, so that`s about as long.

I`ve made repeated measurements over a number of years on the same
repeaters. During normal propagation, which is by far most of the time,
path loss like other system losses is very constant.

Of course there are periods of anomalous propagation. It depends on
location, season, and time of day. It`s worse when the atmosphere is
stagnant.

I`m sure that marginal paths with insufficient clearance and other
problems may have propagation which comes and goes. I`ve seen some, but
I haven`t built any like that.

Best regards, Richard Harrison, KB5WZI

(Richard Harrison) wrote:
Floyd Davidson wrote:
"Richard you can cut the bull**** out."

Floyd claims to have measured microwave paths for 40 years. I`ve been
doing it since 1960, so that`s about as long.

I`ve made repeated measurements over a number of years on the same
repeaters. During normal propagation, which is by far most of the time,
path loss like other system losses is very constant.

Of course there are periods of anomalous propagation. It depends on
location, season, and time of day. It`s worse when the atmosphere is
stagnant.

So now you say it's constant except for when it's not! Your designs
are within 1 dB except when they aren't.

I *am* impressed.

I`m sure that marginal paths with insufficient clearance and other
problems may have propagation which comes and goes. I`ve seen some, but
I haven`t built any like that.

That's why I asked if you'd built many.

In fact it is quit common, and most paths have anomalies. Most of
course aren't very interesting. But others are. Suggesting your
designs have never collided with such an anomaly just means you
either didn't really do many or you're failing to recall them.

--
Floyd L. Davidson http://web.newsguy.com/floyd_davidson
Ukpeagvik (Barrow, Alaska)

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