[amsat-bb] Re: NASA's American Student Moon Orbiter...
G0MRF at aol.com
Thu Jul 3 18:44:25 PDT 2008
In a message dated 04/07/2008 01:16:33 GMT Standard Time,
domenico.i8cvs at tin.it writes:
Hi Ed, KL7UW
If we put AO40 at a distance of 400.000 km instead of 60.000 km
from the earth the increase of isotropic attenuation at 2400 MHz is
about 16 dB etc etc etc.........
Hi Ed / Dom
On the other hand, if you were to reduce path loss by using 70cm as the
uplink band and 2m as the downlink the numbers begin to look quite possible.
Also, if the satellite is orbiting the moon, then it's quite likely that the
attitude will be such that the experimental end of the satellite is pointing
at the moons surface. This probably also means that the communication
antennas are not pointing at the earth, so high gain will not be possible. Maybe 3
or 4dB is the limit.
So how about 10W of 2m on the satellite and a passband that's say 5kHz wide?
Not good for SSB, but passable for CW or reasonable speed coherent BPSK
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