Federal Aviation Administration frequencies?
- Thread starter Lynch_Christopher
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DaveNF2G
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According to the above-linked document, the new system is "FM SSB" - more commonly known as ACSSB. It is not P25, and there are no scanners that can monitor it. You might be able to hear something with a ham rig that tunes that band in SSB mode, but the pilot tone would make listening difficult.
nd5y
Member
That looks like a typo. Whoever wrote that left out some commas. ACSSB is NOT "FM SSB".
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DaveNF2G
Guest
Umm, yes it is. It is abbreviated ACSB or ACSSB depending on which manufacturer's literature you are reading at the moment.
nd5y
Member
ACSSB is amplitude modulated suppressed carrier single sideband with compressed audio and a 3.1 kHz pilot tone. It has nothing to do with FM.
What manufacturer is claiming it is FM?
What manufacturer is claiming it is FM?
Big YMMV but from what I've seen they use a good amount of Motorola gear (CM-200) and ITT (GRT-2x series). They are separate transmit and receive units.
The P25 repeaters are often at RCAG/RCOs but they can be at simple microwave hop sites too. Because they're tied in to the system they need some kind of link connection though. I'm sure the locations vary based on coverage needs.
The FAA uses custom design radios for AM comms in the 118.000 MHz to 137.975 MHz. Up to about 10 - 15 years ago the FAA used a radio, both for vhf and UHF, that was built for the military. When I was in the Air Force, got out 29 years ago, we had these same radios at our RBS radar sites. I didn't work on them I was in radar maintenance.
When I started with the FAA almost 23 years ago, there were the same radios. about 5 - 8 years ago the FAA went to a Motorola designed and built VHF and UHF radio. In the last couple years the FAA went to a new VHF and UHF radio. I don't work in facilities maintenance anymore and I can't remember the manufacturer.
A new purchase initiative for the next generation of radios just started about 6 months ago. This process will take several years before the first transmitter and receiver hits the facilities.
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JStemann
Member
some updates
I guess I kind of lost track of this thread. Anyway, what the above referenced pdf file is showing is that a whole bunch of different types of systems can fall under the broader NRCS system. To the best of my knowledge the SSB they are referring to is just your everyday run-of-the-mill am hf ssb. The HF stuff was installed at centers and "maybe" large tracons to serve as a means of communication in case of a national emergency.
The vhf, uhf can be standard fm, p25 or encrypted. This stuff is normally used for local maintenance activities, although it can be used for just about anything. You would be hard pressed to find it used for any kind of air traffic control activities.
jeff.
I guess I kind of lost track of this thread. Anyway, what the above referenced pdf file is showing is that a whole bunch of different types of systems can fall under the broader NRCS system. To the best of my knowledge the SSB they are referring to is just your everyday run-of-the-mill am hf ssb. The HF stuff was installed at centers and "maybe" large tracons to serve as a means of communication in case of a national emergency.
The vhf, uhf can be standard fm, p25 or encrypted. This stuff is normally used for local maintenance activities, although it can be used for just about anything. You would be hard pressed to find it used for any kind of air traffic control activities.
jeff.
Over the past year has anybody in different parts of the country caught any additional activity on any of these channels? Curious as to how the radio system roll out is going.
I assume that this is still the most recent list?
Zone 1
Channel 1 172.9250 169.3250 - N293
Channel 2 172.9500 169.3500 - N293
Channel 3 172.9750 169.3750 - N293
Channel 4 172.8500 169.2500 - N293
Channel 5 172.8750 169.2750 - N293
Channel 6 166.1000 162.3000 - N293
Channel 7 172.8250 169.2250 - N293
Channel 8 172.9125 169.3125 - N293
Channel 9 172.1250 172.1250 - N293
Channel 10 172.7375 172.7375 - N293
Channel 11 172.1750 172.1750 - N293
Channel 12 166.1750 166.1750 - N293
Zone 2
Channel 1 172.9250 169.3250 - 136.5
Channel 2 172.9500 169.3500 - 136.5
Channel 3 172.9750 169.3750 - 136.5
Channel 4 172.8500 169.2500 - 136.5
Channel 5 172.8750 169.2750 - 136.5
Channel 6 172.9000 169.3000 - 136.5
Channel 7 172.8250 169.2250 - 136.5
Channel 8 172.1250 172.1250 - 136.5
Channel 9 172.1500 172.1500 - 136.5
Channel 10 172.1750 172.1750 - 136.5
Channel 11 166.1750 166.1750 - 136.5
I assume that this is still the most recent list?
Zone 1
Channel 1 172.9250 169.3250 - N293
Channel 2 172.9500 169.3500 - N293
Channel 3 172.9750 169.3750 - N293
Channel 4 172.8500 169.2500 - N293
Channel 5 172.8750 169.2750 - N293
Channel 6 166.1000 162.3000 - N293
Channel 7 172.8250 169.2250 - N293
Channel 8 172.9125 169.3125 - N293
Channel 9 172.1250 172.1250 - N293
Channel 10 172.7375 172.7375 - N293
Channel 11 172.1750 172.1750 - N293
Channel 12 166.1750 166.1750 - N293
Zone 2
Channel 1 172.9250 169.3250 - 136.5
Channel 2 172.9500 169.3500 - 136.5
Channel 3 172.9750 169.3750 - 136.5
Channel 4 172.8500 169.2500 - 136.5
Channel 5 172.8750 169.2750 - 136.5
Channel 6 172.9000 169.3000 - 136.5
Channel 7 172.8250 169.2250 - 136.5
Channel 8 172.1250 172.1250 - 136.5
Channel 9 172.1500 172.1500 - 136.5
Channel 10 172.1750 172.1750 - 136.5
Channel 11 166.1750 166.1750 - 136.5
ecps92
Member
D
DaveNF2G
Guest
Zone 2 Channel 6 is supposed to be an interop for TSA, which uses 172.900 NAC 293 at several airports.
Thanks for the info. The activity that you picked up on the channels was it mostly maintenance related or also some facility to facility comms?
I wonder if the security contractors use these frequencies at the facilities or if they have separate frequencies just for that purpose.
ecps92
Member
Contractors would typically be on a freq licensed to the Company [Contractor] itself for many agencies. There are a few where you might hear them on the Federal Agencies channels, but only a few.
Curious
I'm curious as to what type of communications that occur on these frequencies. From time to time I monitor "FAA Maintenance" requesting ground clearance to enter the airfield. They then proceed to the VOR. I have also monitored an FAA aircraft (the callsign escapes me right now) come to do testing of the glide slope. I have never monitored any traffic on any of the VHF frequencies listed. I understand that they would be operating simplex but I'm within range.
I'm curious as to what type of communications that occur on these frequencies. From time to time I monitor "FAA Maintenance" requesting ground clearance to enter the airfield. They then proceed to the VOR. I have also monitored an FAA aircraft (the callsign escapes me right now) come to do testing of the glide slope. I have never monitored any traffic on any of the VHF frequencies listed. I understand that they would be operating simplex but I'm within range.
nd5y
Member
Years ago in the DFW and Wichita Falls TX area the repeaters had phone patches. I used to hear them used pretty often and used to hear techs talk to each other while driving to and from remote sites. I never heard anything interesting. I think they quit using the repeaters in the early 90s or so when cellphones became cheap and coverage widespread. The last few times I saw FAA vans at the local airport they either had no antennas or only an air band antenna.
ecps92
Member
True they quit using the Analog Rptrs, but left many of them still in place, just unused.
The new Repeaters also have a Phone Patch - Yes.... in P25
The new Repeaters also have a Phone Patch - Yes.... in P25
The initial zone map (put out when the system was designed by Moto) had a zone for digital and one for analog. In some areas, like mine, the techs have access to the programming software for the radios and repeaters and have added/changed stuff.
Somewhere in NorCal is a repeater on 166.0375 N293 which I have yet to see a channel plan with it being used as an output. But it's definitely FAA.
So a YMMV.
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This should help.
National Radio Communications System (NRCS) Digital VHF/FM System
The C3 (Command, Communications, Control) VHF/FM system replaces equipment installed in 1986. The old system supported short-range mobile, handheld, Repeater, and base station communications for routine operations, Tech Ops maintenance, and emergencies. This equipment became difficult and expensive to support logistically and did not meet the requirements mandated by the National Telecommunications and Information Administration (NTIA) requiring a 12.5 kHz digital infrastructure by December 2004.
Purpose:
The C3 system, as used by the FAA, provides national/regional/local maintenance and emergency communications. The primary purpose of the C3 is to support real-time command and control communications during national emergencies, including hijacking, accident investigations, and rescue operations following disasters. During national emergencies and natural disasters, public switched networks may be out of service due to equipment damage or from call saturation, so another means of communications is required. The secondary purpose of the system is to provide day-to-day communications support for routine Technical Operations (Tech Ops) operations and maintenance. These communication needs are met with handheld and mobile radios, consolettes (Low Power Base Stations) fixed Repeaters, high power base stations, remote consoles, portable Repeaters, antennas, encryption key loaders, and communications system analyzers. This system will use the upper half of the VHF/FM frequencies already assigned to the FAA as well as additional frequencies if needed.
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