[amsat-bb] Re: 10' Dish available

[Greg D.]

Bob, Jim,

How does one build a feed to properly illuminate a pizza slice-shaped 
reflector?  Or is this a matter of 1/4 of a 10' dish being still so 
over-kill that you only use the fat end, and under-illuminate that?

Greg  KO6TH


----Original Message Follows----
From: "Robert Bruninga" <bruninga at usna.edu>
Reply-To: bruninga at usna.edu
To: "'Jim Jerzycke'" <kq6ea at pacbell.net>, <amsat-bb at amsat.org>
Subject: [amsat-bb] Re: 10' Dish available
Date: Mon, 16 Oct 2006 11:50:32 -0400

Jim,
Thanks.
I stumbled on that idea when the boss ordered me to the roof to
clean up the old dishes (lost two due to huirricane damage) and
I noticed that one had only a single quadrant that was intact...
Bingo... Couldn't throw it away!  Had to think of a use for
it...

Bob



 > -----Original Message-----
 > From: Jim Jerzycke [mailto:kq6ea at pacbell.net]
 > Sent: Monday, October 16, 2006 10:50 AM
 > To: bruninga at usna.edu; amsat-bb at amsat.org
 > Subject: Re: [amsat-bb] Re: 10' Dish available
 >
 > Bob, Your creativity *never* ceases to amaze me!
 > 73, Jim  KQ6EA
 >
 > --- Robert Bruninga <bruninga at usna.edu> wrote:
 >
 > > > Wow, Gunther!  That is a lot of antenna.  How are
 > > you going
 > > > point that monster?
 > > > Remember, once you can hear the noise floor of the
 > > transponder, then
 > > > additional gain is, well, not needed very much,
 > > let's say
 > > (HI).
 > > >
 > > > >With the coming of the next group of HEO
 > > satellites I am
 > > > >checking if there is any interest in a 10'
 > > Weingard mesh
 > > dish.
 > >
 > > Having collected old 10' dishes myself (with no
 > > practical
 > > applications), I can add these comments too:
 > > 1) The dish is "overkill" for the simple reason,
 > > that AMSAT
 > > would not be designing any transpondrs that would
 > > "require" that
 > > kind of gain, otherwise very few people could use
 > > the satellite.
 > > SO AMSAT designs for smaller more practical size
 > > dishes, lets
 > > say up to 1 meter or maybe 4 feet or so in size.
 > >
 > > 2) But this means that the 10' dish can uaually be
 > > broken up
 > > into 4 quadrants and 4 reasonable sized amateur
 > > radio dishs can
 > > result.  Being 1/4th the size and 1/4th the mass, it
 > > is easier
 > > to build a mount and tracking system.  And the
 > > quadrant will
 > > work just as well as any other approximate 1 meter
 > > antenna with
 > > the proper feed.
 > >
 > > See my web page (near the bottom) on the subject:
 > >  http://www.ew.usna.edu/~bruninga/amsat-ideas.html
 > >
 > > Bob, WB4APR
 > >
 > > _______________________________________________
 > > Sent via AMSAT-BB at amsat.org. Opinions expressed are
 > > those of the author.
 > > Not an AMSAT-NA member? Join now to support the
 > > amateur satellite program!
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 > > http://amsat.org/mailman/listinfo/amsat-bb
 > >
 >
 >

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