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Re: Oscar 0




 Here's an interesting article that I enjoyed so much that I printed it out, and
since the subject has sort of came up, here's the URL. Check it out and kick the
idea around a little. Always interesting to see what others think as well.

http://www.qrz.com/features/Artemis/page1.html

 73 Clinton Herbert AB7RG


Tony Langdon wrote:

> > I think it is very intriguing to put an amateur transponder
> > on the moon,
> > but before we
> > get started let's do the link margin calculations. The moon
> > is very very
> > far away and
> > most hams will not be able to work a lunar transponder with
> > an HT and an
> > arrow
> > antenna. Only those "elite" hams with big antenna arrays in their
> > non-covenant
> > restricted backyards will be able to work a repeater on the moon, and
> > once it is
> > deployed there we will no doubt see postings on amsat-bb about how
> > "Amsat builds satellites for the elite minority and not for
> > the average
> > ham."  So lets make sure that
> > everybody understands this up front.
>
> I'd done some rough sums in my head and came to this conclusion.  Has anyone
> done a reasonably accurate link calculation for a lunar transponder?  And
> what sort of antennas would we use?  That would no doubt depend on how
> accurately we can point the things.  Even on the lunar surface, thich
> "nominally" faces the Earth, there is enough libration to limit the antenna
> gain that can be used before a tracking antenna is necessary to keep Earth
> within the beam.
>
> > radio operators, and only to an elite group of hams at that. But it
> > can't hurt to ask.
>
> Never hurts to ask. :)
> >
> > With the passing of Werner Haas, Amsat has lost more than half of its
> > linear
> > transponder design knowledge. Werner designed and built most of the
> > communications payload for AO-10, AO-13 and Phase 3D. I frankly don't
> > know
> > who is going to step forward to fill those shoes. I don't
> > know of anyone
>
> Maybe there's an object lesson here about putting one's eggs in the same
> basket (or brain, in this case).  Unless technologies used by AMSAT are
> documented and kept in a safe (but accessible) place, this will happen
> again, with the associated cost of re-learning the art.
>
> ----
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