On Thu, 09 Apr 2009 10:01:32 +0200, Emanuele Colucci
wrote:

well, searching for "cassegrain antenna" with google only gives 60,400
links, searching for "cassegrain antenna design and construction"
narrows it down to about 4000.

It's April, 9th, 2009. By this date I still wonder why there are persons
so arrogant to think that who asks for advices never looked at google.

Hi Emanuele,

This is probably due to the way the question was offered. You want a
complete solution to an unknown problem. When such "wish lists" are
posted here, they obtain one of several results:
1. An exhaustive reply that is complete to the question asked, but we
then have the luxury of reading from the original poster that "that
specific solution won't work because...."
2. The beginning of an exhaustive series of postings to draw the
specific issues out of the original poster. That has already begun by
another poster in this thread.
3. The fire hose is opened (much as above) which is another form of
(2) in that you imply you have done a google search, but you haven't
expressed what your search terms were - which would, of course, reduce
those 60,400 links to something more tractable. You don't offer
anything like this in your response except outrage.

Each of these possible outcomes inevitable returns to you, and
something you could have done first instead of last: What is your
problem, why do you think this (a "cassegrain antenna") is the
solution, and some fundamental design issues such as
1. Frequency;
2. Bandwidth;
3. Match;
4. Gain;
5. Budget (time and/or money);
6. Specific issues (phase control?);
7. Application issues (EME?).

When such things are asked for, students coming here to complete an
homework assignment are usually stunned. If you are not a student,
then an engineer is always prepared to submit the characteristics
required. If you are not a student, nor an engineer, then almost any
quick answer could lead you down the path to lost time. You are lucky
no one supplied that quick answer, because we have enough miracle
antenna designers who come here to do just that.

73's
Richard Clark, KB7QHC