The big LNB in the middle is for Ka band and circular.
The outboard LNBs are circular Ku.
While the dish is on the small side and not a good starter dish for someone just getting into the hobby , it'd be fine for an extra dish for some of the stronger transponders you might want.
As mentioned, a proper LNBf will need to be fitted at the center mounting position.
edit:
The sturdy mount is very nice for aiming at a fixed bird, but way too heavy (and the dish too small) to put on a motor.
In fact, if you decided to throw away the dish, ya might keep the mount for future projects.
If you put a linear LNBF on it you could get some FTA stuff. But like Anole said it's not a good starter dish. Once you get deep into the hobby and good at finding birds it could be allot of fun to mess with. Put it on the side for down the road and get a 80 to 90 cm dish and get pointing. Once you master finding the birds get a diseqc switch and another FSS LNBF. Then make a bracket for the direct dish and point it a a strong bird and look at 2 birds at once
OK thanks to all of you for all the very good info.
1. I thought that I would not have to replace the big center LNB since it is also Ka/Ku combo LNB.
2. The bracket has 'special' bolts on it which I assume are used to set the EL/AZ/Skew?
Here's your dish on the SolidSignal web site.
Click on the tab under the pictures, marked: Documentation.
Read the AT9 Install Manual .PDF for a good understanding of how everything works.
The install videos no longer seem to be on their web site.
I have them archived, and enjoyed watching 'em several years back, but since you're not aiming at a Ka bird, they aren't really all that useful.