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@usna.edu Reply-To: bruninga@usna.edu To: "'Jim Jerzycke'" kq6ea@pacbell.net, amsat-bb@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@pacbell.net] Sent: Monday, October 16, 2006 10:50 AM To: bruninga@usna.edu; amsat-bb@amsat.org Subject: Re: [amsat-bb] Re: 10' Dish available
Bob, Your creativity *never* ceases to amaze me! 73, Jim KQ6EA
--- Robert Bruninga bruninga@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:
- 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.
- 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@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
_______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
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