Dennis:
You bring up a point that has been bothering me. My JR Radios have the "module" you are talking about. I believe you are talking about the crystal, which in some radios can be changed very easily without opening the case. You obviously have to match a Receiver crystal with the same channel with the one on the Transmitter. The problem is, you are not allowed to change it (?) since by Federal Law, you are supposed to send the transmitter in for the crystal to be plugged in and the radio "re-tunned" to that frequency. This can only be done by authorized companies (?). I know of someone who has changed crystals back and forth in order to use his radio on planes with different channels, but this is supposedly ilegal. He says he has never had a problem.
Can you comment on this?
Thanks
Luis