Yeah, course you can, do you think all the houses you see with dishes are only running one box!
On the line from the dish just put in a 'splitter' and run off your other box,,,
You should be able to run 3-4 boxes from one dish before the signal weakens too much,,,
Probably get some more replies soon,,,,,,
Or you can do it the cheap way without another box:
Sky Extender
