Is all air radio AM?

[lhbadman]

Great forums- hello to all. Just want a sanity check-I am working from the belief that pretty much all air traffic is AM, just simple AM, for the most part. I know ground ops tend to be FM, but the actual airborne stuff is AM- or am I wrong and missing something? I listen to aircraft with the Sony 2010 (largely deaf), Icom R3 (so-so), Bearcat 246T (just got it, showing promise), and the Yaesu FT-90 Dual-Band Amateur radio with wide receive in the truck. Still looking for the Holy Grail of aircraft listening info- though RR has a bit of info, as does the likes of Monitoring Times- but just want to make sure I'm not missing anything in howI use my gear or what I'm using for reference as I get into the aircraft thing (do a lot of ham work, but monitoring is becoming more of an interest).

Regards-

Lee
KC2IYK

 

[LarrySC]

Low-band mil comms 30 to 50 mHz is FM. Some reports of PL tone near 151.4 but not exact. CAP comms 148mHz FM.

 

[ReceiverBeaver]

All air comms on HF like military plain voice and intercontinental commercial aviation will be on USB (upper sideband).

Beavers don't care what mode you use, they'll chew anything.

 

[DPD1]

Every once in a great while, there will be UHF FM usage on something as well... Maybe a squadron base, or a tactical freq where data is passed. But it's very rare.

Dave
http://www.DPDProductions.com
- Custom Scanner, MURS, GMRS, & Ham Antennas -

 

[brandon]

Satcom in the 260 mhz range is NFM for voice comms.

 

[MacombMonitor]

Satcom in the 260 mhz range is NFM for voice comms.

What can be heard on Satcom?

Thanks!

 

[illini52]

Low-band mil comms 30 to 50 mHz is FM. Some reports of PL tone near 151.4 but not exact. CAP comms 148mHz FM.

The stuff 30-88 MHz FM is 150 hz tone. That's the mil standard.

 

[thepilot21]

Aviation listening is fun!

Lee,

The simple answer to your question is yes, the very very large majority of aviation communication is AM. Most average run-of-the-mill communication in civil aviation in the United States occurs between 108 and 136.975 MHz. Most scanners default to AM in this band. 108 to 118 is typically receive-only for aircraft, as this is where many navigation aids transmit.

The main band for most planes at your local airport and at all civil aviation airports in the United States is 118-136.975. Here you'll hear the tower, ground control, approach control, and en route control. Also you'll hear ATIS and AWOS broadcasts at large and medium size airports, a continuous transmission of real time weather observation and announcements about the airport which the pilots listen to before takeoff or before arriving at the airport.

Additionally, roughly from 129.0 to 132.0 is a small sub band reserved for commercial purposes, not used for any air traffic control (ATC) purposes. 121.5 is the EMERGENCY frequency, and from 121.6 to about 123.6, various frequencies are allocated for different special purposes, including use at all airports with no control tower where pilots self announce.

Military aviation occurs mostly from 225 to 400 MHz and most of this is also AM, but there are a few exceptions. International aviation, especially air traffic over oceans uses shortwave bands as one of the other posters indicated, and this is Upper Side Band (USB). Ground crews at airports often use FM radios no different than any other business. The military has the most exceptions as various frequencies between 30 and 50 MHz are used with either FM or AM, and some military aviation and other military or federal occurs in 137-144 and may be AM or FM, as well as in the federal band in 162-174 and 400-420. Most federal is FM (or moving to APCO 25), but if it's military and especially mil air, it may be AM or FM in those federal bands.

To repeat, the first place to start with listening to airplanes is 108 to 136.975, and this is AM. http://www.airnav.com is a great place for useful information on your local airport. Frequencies are listed. Plug them in and eventually you will hear something.

Good luck and happy listening!

 

[lhbadman]

Great info- Thanks

Tom, and all-

Excellent info, thanks for helping me stay on track. I have the BC246T scanner- not bad on air, depending on what antenna I put on it, the Sony 2010 which has "AirBand" but is deafer than a box of deaf rocks, and the Icom R3, which is fair but a wee bit clunky.

Thanks again-

Lee
KC2IYK

 

[CLB]

CAP air to ground is FM simplex, and in a DIRE situation, duplex only on the repeater tone that is needed. I actually installed a VHF CAP radio in my truck 20 minutes ago.

As far as 30-50 mhz FM, I've talked to MANY Air Force, Army and Navy pilots that ALL have said it is rarely to near guaranteed never used anymore. Most Command Posts (Air Force at least) are on VHF are 134 Mhz, and that's only really there for commercial freighters (747's, DC-10's etc...) that have a contract to carry government freight or again, a CAP aircraft that has authorization to land at an active military airbase. They don't have as they call it "Uniform Capability" (UHF).

Side note: The only orginization that still uses 30-50 Mhz that I've personally heard is the North Carolina HP. I'm sure there are others out there, but not in the air.