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RE: About ALON/ALAT of AO-40



Stacey Mills wrote:

Assuming a constant
squint, the change in footprint, for example, between 40,000 km of altitude
and 58,000 km of altitude is not great, but the path loss for the additional
18,000 km is a potentially big factor.

Wayne replies:

When I said "larger coverage area", I didn't mean "bigger footprint".  I
know the footprint doesn't get significantly larger from 40,000km to
58,000km.  But the "coverage area" of a 12 hour pass is significantly larger
than for a 4-hour pass, as the footprint gradually moves west for the
duration of the pass.  If a station is near the western edge of the
footprint at AOS, the station will start with tremendous DX range to the
east, and then end the pass with tremendous DX range to the west near LOS.
Thus, the "coverage area" of a 12-hour pass can be up to twice as large as
the "footprint".

Stacey wrote:

However, for demonstration purposes, the booming signals currently heard
with low squints at relatively low altitude are plenty impressive.

Wayne replies:

I hope you didn't interpret my previous message as a complaint.  I was
merely pointing out that the exact rate of change of alon does matter when
making long-range plans for a time-specific activity.  In my case, the
"booming signals" will end about the time the demonstration starts.  Signals
would have been good for the duration of the hamfest if the alon improvement
was actually 1 degree per day since early February.  I'm not blaming
anybody, just pointing out that small changes over a long period of time do
make a difference when dealing with a fixed time schedule for a
demonstration.

I really appreciate your detailed explanations of the recent activities and
future plans of the AO40 command team.

Most importantly, I hope the transponder will stay on well past MA100,
because it's now shutting off when the squint angle is still tolerable.

Wayne Estes W9AE
Mundelein, IL, USA



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