Can someone please define the different between FM and NFM I have all of my RISCON and Anolog on NFM and it sounds great However when I look at the United States Coast Gaurd frequencies on RR it lists all of them as FM modulation but if I search the same USCG frequencies on my scanners search mode it defaults to NFM Should I set my scanner to FM or NFM? Thank you
FM on scanners is usually 5KHz deviation, or the amount of maximum deviation off the center frequency. In the two way radio industry, this is considered "wide"
NFM is 2.5KHz deviation.
Most VHF and UHF LMR frequencies in the USA were moved to narrow band starting in 2013. There are a few specific frequencies and specific sections of the LMR bands that stayed wide, like T-band UHF, GMRS and some paging frequencies.
Marine VHF, however, was not required to change to narrow band in 2013. Because it is a worldwide standard, it stayed wide.
Marine VHF channels should be set to FM on your scanner for them to sound right on your radio.
