Suggestion: Visit
http://www.setileague.org/hardware/parabola.htm
http://www.cwc.nus.edu.sg/~chenzn/MC6-antenna.pdf
etc. for more info

Suggestion: Visit
http://www.telsat.com/garyb.htm
etc. for more info

thanks j.
but there would be any simplified design/diagrams?

Review Chapter 17 from "Antenna Engineering Handbook" second edition edited by Johnson and Jasik.  Many university engineering libraries carry this book (as opposed to purchasing).

I've been searching casually for this information for some time.  The .pdf referenced by jbartos is the *first time I've even found numbers.  What's so frustrating about the search, though, is that it should be so simple.  y = ax^2 + bx + c.  Differential theta summation -or whatever- just shouldn't be in it.  

I have to assume the name is a dirty, dirty lie, as there's just not a website telling us the three missing variables.  Gotta figure distance of the microphone from formost edge of the disk is one.  Counter-intuitive as it is with a 3d object, I don't believe there's a Z.  (X = distance from disk's radial center, Y = depth from rim.)  So what remaining variables there are is a mystery.  
  
Ah, well.  If you get anywhere, Yan, I hope you'll let me know.

*=Actually, I got a formula from an e-mail group I was on.  Naturally this evil datum let smoke out of that PC within a day or two, so I didn't get a chance to write it down, back it up or test it.  Dunno if it was even valid.  I tell myself, of course, that it wasn't.

Are you sure that 6-foot will be sufficient for C-band TVRO?  I recently read that 7.5-foot was the smallest practical size - assuming that you're using a good, state of the art, LNBF.