Yes, you can use item# 14 here:
http://sadoun.com/Sat/Order/Switches.htm
However, make sure you only use one receiver at a time and you have to turn the other receiver OFF. I would also recommend you use DC block (usually found at Radio Schak) on each output of the switch. That way voltage will pass in one direction (towards the LNBF) and not towards the other receiver.