i too have to solve this problem,
i used hitec 40, 2 complete sets, and futaba 40. still got range problems
and to be honest i'm so fed up with it the marders sat in the garage
while i run the electric.[X(]
but as for the 27 get off it.
everything uses the 27 freq, C.B.s, kids rc toys, walkie talkys, some pagers, etc