Isn't there a certain number of digits that you are to remain above or below the actual number given on the receiver from Futaba if you can not match the original crystal number exactly.
For example you purchase a Flight Pack with no crystal, but it was on channel RX23.
What crystal # can you use in it. Let's say a #RX38?
I emailed Futaba and of coarse they say because of FCC and safety reasons they can not recommend changing the crystals even in the receiver w/o sending it in for re-calibration or checking of the Tuning.
I am just looking for second opinions.

Thanks
Hootcher