I've searched the archives, but no answer to exactly what I'm asking.

I just bought a simple RC heli. It came with two crystals (of
course), TX and RX. They are, however, not the same *frequencies*;
they are 72.89 M and 72.97 M, or something similar (but they're close
together). TowerHobbies' website also shows some crystal sets with
the TX and RX being different *types* (like 72-7 FM TX and 72-12 FM
RX) for the same set.

But, other crystal sets have TX and RX at the *same* frequency.
How can this be?


Do my crystals count as a matched set? The heli does not work yet, and I wonder if that is why (the range is only 1/2 foot with good batteries; needs frequency tuning?)

I am new to RC, and so I clearly need _big_ help with simple matters