The 6x8 is only good for a HD setup. Check the link below and match your dish type and then you'll see compatible switches. You CANNOT use any type of splitters with non SWM setups.
http://www.solidsignal.com/p/?p=2709&d=directv-dish-antenna-types&mc=02
http://www.solidsignal.com/p/?p=2709&d=directv-dish-antenna-types&mc=02