bigger is not always better
If you are looking for Ku-band reception, a 36" dish is a good choice.
If you are looking for C-band reception, then 8', 10', maybe 12' is appropriate.
However, the 8' dish won't get you 7-times better signal on Ku band.
A far better choice would be a 1m Primestar, if you can find one.
Motorizing a Ku band dish is a lot easier and cheaper than a C-band BUD.
Takes different equipment, space, experience, and dedication.
While any decent DBV FTA receiver will operate on both bands, the antenna setup should probably be separate to allow for debugging and learning.
Code:
[FONT=Fixedsys] ...
Surface area of common sized dishes
square inches dish size
------------- -----------
707 30" or 76cm
1018 36" or 90cm
1256 40" or 1 meter
4071 72" or 6 feet
7238 96" or 8 feet[/FONT]
Well, that is my opinion, and as such is one data point.
You will get many more.
Oh, and nobody listens on
Ka band, these days.