NAM ? Never heard of it - should it be NFM or NBFM ?
If you have genuine FM with the standard 75 kHz deviation then it occupies on average 225 kHz all by itself. No need for anything else to punch a hole in the tones ! If that is the case something weird going on, but you are on the spot.
You have never heard of NAM you live and learn.
NAM = Narrow AM
Frequency Coverage: 531kHz - 1320Mhz continuous
Modes of FM, WFM, AM, NAM, USB, LSB, CW
Step sizes: 50Hz, 100Hz, 1kHz, 5kHz, 6.25kHz, 8.33khz, 9kHz, 10kHz, 12.5kHz, 15kHz, 20kHz, 25kHz, 30kHz, 30kHz, 100kHz, 125kHz
