Question regarding Crystals
Yes.
Sec. 95.222 (R/C Rule 22) May I make any changes to my R/C station transmitter?
(a) You must not make or have anyone else make an internal
modification to your R/C transmitter.
(b) Internal modification does not include:
.....
(2) Changing plug-in modules which were certificated as part of your R/C transmitter.
HTH -Steve