Modulation: NFM vs. FM

This is the place to discuss Riverside County scanning related topics. Whether it be something about a particular agency, radios, antennas, or other general scanner related questions, you can talk about it here.
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convE36
Posts: 192
Joined: Sun May 04, 2008 5:42 pm

Modulation: NFM vs. FM

Post by convE36 »

What is the difference? Should I just keep my scanner in "auto" mode under the modulation menu.

If I do a random search through the 800Mhz band, my scanner says NFM...

When I scan my programmed system for RSO it says FM, but there is no menu to change the modulation for the trunked system...(BC246T)

Canyon Lake POA = NFM or FM?
zz0468
Posts: 236
Joined: Wed Jun 18, 2008 8:35 pm

Re: Modulation: NFM vs. FM

Post by zz0468 »

FM = 5 KHz deviation, NFM is probably 2.5 KHz deviation. That's the short answer. Ask if you want the long answer. I see no need to confuse...

Do a license search for the frequency you want to monitor. If it comes back as 16K0 or 20K0, it's wide fm, or 5 KHz dev. 11K0 would be narrow. Most of the Riverside County stuff is licensed at 20K0, FM would be appropriate. Same with Canyon Lake. If you're listening to 900 MHz stuff like the Edison system, that's going to be NFM, as will refarmed narrow band VHF channels.
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