NFM: Ae These Modes Correct ?

[BOBRR]

--Guess I originally posted in the wrong foru, so let me correct, and re-post here:--

Hello,

Correct modes always drive me batty. Age thing, I guess.

Am I correct that all of the following should be NFM:

Police and Fire from:

Boston

Natick
Framingham
Stow
Wayland
Waltham
Weston

Any that aren't, or any caveats ?

Thanks,
Bob

 

[n5ims]

Since you're asking about non-federal Police and Fire frequencies (those all should be Part-90 frequencies), the simple answer is if their frequency starts with a 1 or a 4 (1xx.xxx MHz or 4xx.xxx MHz) it should be narrow-FM (NFM) if they broadcast in standard analog mode. Digital modes or trunked systems will have their own modulation types, but neither FM nor NFM would be appropriate for them.

If they use low-band (30 - 50 MHz) they'll still be FM. If they use the 700, 800, or 900 MHz bands, they'll probably be narrow, but your scanner will default correctly since those bands haven't changed.

Don't get confused by trying to mix the Part-90 frequencies (that the PD, FD, etc. use) with the other types of radios that don't require a license or are licensed for more of a hobby type of communication. They have their own set of rules and don't follow what the Part-90 rules are. Examples of these are hams (Part-97), Marine (Part-80), and MURS, GMRS, and FRS (Part-95). The aircraft bands are also different, but they use AM, not FM to transmit so the FM or NFM option would be moot there as well.

 

[ecps92]

Almost correct.
Remember Boston has T-Band, so some 47x.xxxx and 48x.xxxx may or may NOT be NFM, all depends on the Tech/Agency. Most did as they also have access to some 453/460 channels and had to edit the portables/mobiles anyway.

Also there are some who didn't yet in 15x.xxxx

Since you're asking about non-federal Police and Fire frequencies (those all should be Part-90 frequencies), the simple answer is if their frequency starts with a 1 or a 4 (1xx.xxx MHz or 4xx.xxx MHz) it should be narrow-FM (NFM) if they broadcast in standard analog mode. Digital modes or trunked systems will have their own modulation types, but neither FM nor NFM would be appropriate for them.

If they use low-band (30 - 50 MHz) they'll still be FM. If they use the 700, 800, or 900 MHz bands, they'll probably be narrow, but your scanner will default correctly since those bands haven't changed.

Don't get confused by trying to mix the Part-90 frequencies (that the PD, FD, etc. use) with the other types of radios that don't require a license or are licensed for more of a hobby type of communication. They have their own set of rules and don't follow what the Part-90 rules are. Examples of these are hams (Part-97), Marine (Part-80), and MURS, GMRS, and FRS (Part-95). The aircraft bands are also different, but they use AM, not FM to transmit so the FM or NFM option would be moot there as well.

 

[ecps92]

Specific Freqs would be better than Agency names, since some (Like Boston Police still have Low-Band, and Boston EMS has a Paging Only which did not have to Narrowband)

--Guess I originally posted in the wrong foru, so let me correct, and re-post here:--

Hello,

Correct modes always drive me batty. Age thing, I guess.

Am I correct that all of the following should be NFM:

Police and Fire from:

Boston

Natick
Framingham
Stow
Wayland
Waltham
Weston

Any that aren't, or any caveats ?

Thanks,
Bob

 

[WA0CBW]

You can also go the the FCC web site and look up the agency and their frequencies and it will tell you the type of emission and bandwidth they are authorized to use.

 

[N1BHH]

You can also go the the FCC web site and look up the agency and their frequencies and it will tell you the type of emission and bandwidth they are authorized to use.

It does not necessarily tell you if they are actually narrow band. As ecps92 says above, some may or may not be NFM.