• Effective immediately we will be deleting, without notice, any negative threads or posts that deal with the use of encryption and streaming of scanner audio.

    We've noticed a huge increase in rants and negative posts that revolve around agencies going to encryption due to the broadcasting of scanner audio on the internet. It's now worn out and continues to be the same recycled rants. These rants hijack the threads and derail the conversation. They no longer have a place anywhere on this forum other than in the designated threads in the Rants forum in the Tavern.

    If you violate these guidelines your post will be deleted without notice and an infraction will be issued. We are not against discussion of this issue. You just need to do it in the right place. For example:
    https://forums.radioreference.com/rants/224104-official-thread-live-audio-feeds-scanners-wait-encryption.html

FMN Mode?? For Aircraft

Status
Not open for further replies.

Cannondale900

Member
Joined
Mar 27, 2011
Messages
2
Location
CA

Comint

Member
Database Admin
Joined
May 21, 2003
Messages
629
Location
Queensland, Australia
I wanted to listen to the local CDF air ops and noticed that the mode that these frequencies are in are called FMN. What does this mean. My local airport and other aircraft frequencies use AM. My radio shack scanner does not have this mode on it. Would AM work? or is this a special type of frequency only expensive scanners can hear?
It would help if you stated the model number of your scanner, and the CDF air op frequencies you want to monitor.
Most, if not all, Radio Shack scanners have FM.

--
Comint
 

mass-man

Member
Joined
Mar 15, 2004
Messages
950
Location
Big D, little a, double l, a s
This is a WAG, but you may have seen a freq for a ground to air channel. Means they put the FM radios in the planes to allow better communications. But again, post info from the DB and you might get a more informed answer!
 

N8IAA

Member
Joined
Dec 19, 2002
Messages
6,704
Location
Fortunately, GA
I wanted to listen to the local CDF air ops and noticed that the mode that these frequencies are in are called FMN. What does this mean. My local airport and other aircraft frequencies use AM. My radio shack scanner does not have this mode on it. Would AM work? or is this a special type of frequency only expensive scanners can hear?

thanks!!


Department of Forestry & Fire Protection (CAL FIRE) Scanner Frequencies and Radio Frequency Reference
Valid question. Enter the frequency in FM, not AM. You will just hear noise on that frequency in AM. Most, if not all, air to ground frequencies for forestry across the country is in the FM mode. The FMN mode is a bit confusing if you're not familiar with all the flavors of FM. It is the common bandwidth of the radios currently being used. When it transitions to NFM in a couple of years, you will notice a difference in the loudness of audio. Then it will be time to upgrade to a receiver that does NFM. Unless, of course, it doesn't bother you:)
HTH,
Larry
 

majoco

Member
Joined
Dec 25, 2008
Messages
3,193
Location
New Zealand
I doubt that the aircaft itself has been fitted with an NFM R/T on the normal aircraft band - probably someone using a handheld with maybe an external antenna. Done it myself - from 14,000feet you can cover an awful lot of New Zealand with 2 watts!
 

mm

Member
Joined
Dec 19, 2002
Messages
610
all of the CDFaviation radios in use, be them the Wulfsberg RT5000 line, the Nat NPX radios or the technisonics TDFM line of radios are all capable of Narrow FM (12.5Khz channel spacings) ,standard FM (25KHz channel spacings) and P25 digital on all of their channels.

The CDF Wulfsberg RT5000 radios cover 29.7 to 960 MHz and does as I said NFM, std FM , P25 in the 137 to 174, 384 to 520 and 700/800 MHz public safety bands, it also does AM from 29.7 to 400 Mhz.

The Technisonic aviation radios have similar coverage so yes they do have narrow FM capability and have had it for years. The NAT radios only cover 137 to 174 MHz but only in all FM and P25 bandwidths.

The Wulfsberg RT5000 came out around 1992 and CDF has been using them for this long of a time with some upgrades over the years to digital P25.
 

bryan_herbert

Member
Premium Subscriber
Joined
Oct 31, 2006
Messages
1,055
Location
Las Vegas, NV. DM26jc
The 151, 171 and 173 MHz air ops frequencies used by Cal Fire, BLM, USFS and NIFC are Narrow FM but if your scanner was manufactured in the last 5-10 years it shouldnt have a problem receiving the frequencies. The audio might be a bit lower though. Also keep in mind unlike traditional AM aircraft communications 'capture effect' is a factor with FM so your reception range is cut by half if not more.
 

Cannondale900

Member
Joined
Mar 27, 2011
Messages
2
Location
CA
thanks for the replies! my scanner is a RadioShack PRO-163 Base Trunking Police Scanner. i think that i understand the difference now. Also, i see some other sites have different frequencies for fire departments and such. it seems that this site has is stuff together and lays everything out real well. are most of these frequencies for placer county CA or really any frequency on this site for any county or state the most up to date?
 
Status
Not open for further replies.
Top