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