After dipping toe into water with my HK Orange OpenLRS system ( It worked briefly :D ), I started to wonder what RF I.C.s were being used in the various UHF RC systems. Found this link on RC groups as a start:
http://www.rcgroups.com/forums/showthread.php?t=1889412 (http://www.rcgroups.com/forums/showthread.php?t=1889412)
Makes interesting reading, especially when you compare the differences in RR prices of the finished products!
regards
Andy