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Re: AMSAT has a SECRET: why not 10m instead of V band



An interesting idea, but for the sake of completeness, there is some
disadvantage to 10m.

1. I have heard from EU operators that there is significant interference
even on the so-called "satellite" portion of 10m.
2. At low elevation angles (I suppose for a high-orbit satellite this
won't happen often as a fraction of total visibility) 10m will be
"captured" by topside reflection from the ionosphere.  Just this
afternoon I went out to the truck for a RS-12 pass that was max.
elevation 6 degrees for me, and I could only just barely hear the beacon
the whole way.  It usually takes 10 degrees or so during the day for me
to work anything, due to the fact that the downlink just doesn't make it
thru the ionosphere.  Totally different later at night or very early in
the morning, I can work it down to less than 2 degrees typically (so
it's not an installation issue).
3. Not a whole lot of bandwidth available in the satellite portion of
10m.

...for the satellite experts to work out.  Just my $0.02 (and probably
worth just that!)


sco@sco-inc.com wrote:

> 
> I might do away with a 2m link in favor of a 10m downlink capability. That
> way any ham or SWL who has a general coverage receiver 160-10m will be able
> to hear the satellite. Once they hear it they might get interested and want
> to talk thru it too. I would suggest that more people  (hams and SWLs) have
> a general coverage HF receiver as compared to an all mode VHF receiver.
> They are less expensive to buy too.
> 
> A 10m downlink could be heard well on a dipole antenna.
> 
> Make a satellite in an AO-40 orbit (that was planned).
> With 10m and S band downlinks.
> With U and L band uplinks.
> 
> W4SCO
> 
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