[wejones]

Originally Posted by reho33

Can a 6 foot prime focus dish be used for Ku? And if one were to do so, how would a person find the actual elevation settings for it as the settings given by most calculators only do it for offset dishes?. Lastly, would the adjustments be a lot more critical than a 3' dish? And how much more gain and adjacent satellite rejection would one expect?

Yes, a 6 foot dish can be used for Ku. What Steve says about sidelobes is not so much a function of dish size, but dish quality, and I believe also the F/D ratio (I think high F/D dishes work better). I use a 10' dish, and I have bad sidelobes, which sometimes confuses things, however it works just fine most of the time. My current sidelobes are partially due to the quality of the dish, and partly because of the fact that I dropped the dish from 8' when I installed it, and due to the fact that I beat it with a broom every winter to knock snow and ice off, so it is all dented. My previous 10' dish had much less in the way of sidelobes, and worked very well on Ku. Basically, if you have a new relatively good quality dish, the sidelobes won't bother you, but if you're thinking buying a used dish that may have been abused, you might have a problem. My first of 3 10' dishes didn't work well at all on Ku, because it was an old 1980's era C-band dish, that wasn't shaped well, and had big mesh.
I also have a 6' dish, that originally worked well on Ku ( according to the guy I bought it from ), but it doesn't work worth a darn now, mainly because I left it out in the freezing rain over a couple winters, and the hollow ribs filled with water, froze, and split, which warped the thing badly.
So if you're buying a new dish, I think a 6' dish should be fine on Ku.

Now... for declination numbers, you could use my on line calculator, at:

http://wejones.ftdata.com/bjdishcalc2.htm

or go to my page, ie:

http://www.megalink.net/~wejones/inst&align.html

I have a program there that calculates Az/El and declination, etc.

However I really like to recommend :

http://www.geo-orbit.org/sizepgs/tuningp2.html

which is about the best web page out there for aligning TVRO systems.

Relative to elevation and declination, you can use the declination calculator at the Sadoun page, but it is calculating the elevations and declinations for a south facing satellite, which is OK for smaller dishes, but is not the declination you should be using for bigger dishes, which require more accurate tracking.
The Geo-orbit page above explains this, and has charts for both.

If your dish isn't motorized, but instead and Az/El, then you could just use the Az/El found at the Sadoun site, as they are the same for either offset or prime focus.