RE: FCC 'type acceptance' and modules
I think you will be fine. The issue is the RF desk and it's interface to the radio. Going in via a DSC CORD (chord is in music . . . ) does not change this interface - it will ultimately give a different set of control signals to the RF deck, but the interface in the radio will still determine the signal level and thus deviation of the RF deck. To the comments by apteryx, the signal level to an FM transmitter is just as crucial to bandwidth, if not more so that in AM - since the singnal strength into an FM transmitter determines frequency shift, to high a level will violate the narrow band specs in a hurry. On AM, if the singnal in is always "clean", you won't go out of band by increasing signal level until the transmitter starts to clip (being driven beyond it's power capacity" and then it goes really ugly really fast - not just wider, but all over the map.
- Tim