O'Hare ARINC / ARINC IDent System / NAC Question????

[KC9NCF]

As I look over the ARIND ID system, I only see three freqs with no showing in that listing for control frequencies. Are the control freqs the same as with the original ARINC system? Are there just not control freqs for the ARINC ID system? If there aren't any control freqs, how does the ARINC ID system work?

Can it be picked up in the inner city or do you just have to be near ORD to receive the system? Is the O'Hare 400Mhz trunked system still in use? Is it and the United Airlines T-System worth programming in?

Any reccomendations for good handheld scanners to receive this system on? The BCT series is obviously going to be mentioned as will that new PSR radio. Does Radioshack have something that will receive these systems? If so, does any of their models decipher NAC codes and what is an NAC code? How does an NAC code work?

 

[Astro25]

RadioShack scanners in general suck and are overpriced. The only decent ones I have ever owned are the Pro-2055.

The GRE PSR series handheld scanners will decode the NAC. The Unidens will not, however I have the BCT-15 and BCT996D and they both are supurb scanners.

A NAC is like a PL tone for digital. For example, NAC $293 is kind of like the "carrier squelch" CSQ for digital, wheres NAC $BAD is different NAC (you can have alphanumerics in the NAC).

 

[markinillinois]

129.45 is the only ARINC frequency I see that has a Chicago transmitter site.

The 129.35 frequency network begins just to your south and extends east from St. Louis to New York, the 129.4 frequency network begins just to your northeast and extends east to Maine and the 131.8 frequency network is just to your northwest and extends west to Seattle. All of these frequencies show transmitter sites beyond Chicago.

Mark Holmes
Marion, IL

 

[KC9NCF]

129.45 is the only ARINC frequency I see that has a Chicago transmitter site.

The 129.35 frequency network begins just to your south and extends east from St. Louis to New York, the 129.4 frequency network begins just to your northeast and extends east to Maine and the 131.8 frequency network is just to your northwest and extends west to Seattle. All of these frequencies show transmitter sites beyond Chicago.

Mark Holmes
Marion, IL

These are the systems I was talking about:

http://www.radioreference.com/apps/db/?sid=584

http://www.radioreference.com/apps/db/?sid=5740

I should have provided the links earlier to avoid confusion. Thanks for any further help on the topic.

 

[chgomonitor]

O'Hare ARINC / ASRI Trunked / IDEN System

The system is very, very low power. It becomes very hard to hear more than a mile or two from the field. For accurate trunk tracking you almost have to be actually on the grounds.

The system carries both IDEN and trunked communications. Since we don't have a scanner capable of handling IDEN, verifying exactly what is happening with IDEN portion of the system is problematic - to say the least.

System ID: 1216 Connect Tone: 83.72 Hz Uniden Fleet Map: B0-1, B1-5, B2-2, B3-2, B4/5-12, B6-2, B7-4
Apparently transitioned to Iden only service: 855.9375 855.0875 856.3375
Analog frequencies: 857.3375 858.3375 859.3375 860.3375
856.8875 857.8875 858.8875 859.8875 860.8875

The last time I was on-field (two months ago) the system was still up and running as roughly outlined above.

There are a lot of IDEN users in the international terminal, as well as other areas. The radios look almost like a PDA and are reportedly capable of handling some data signals and even small graphics.

American Airlines and American Eagle remain the major users of the analog portion of the system.

It's getting a bit long in the tooth and needs some updates but you'll find info on this and most other O'Hare radio systems over at:

http://www.carmachicago.com/profiles/OHareAirport.pdf

Happy Scanning! - Ted

 

[chgomonitor]

O'Hare 400 Trunked

The city's 470 MHz trunked system is up and running and digital. Very busy with mostly non-public safety airport functions. Most city public safety and related stuff and the plows are up on the O'Hare 800 MHz analog city system.

United seems to have abandoned their old analog 464 MHz interstitial frequencies and are busier than ever on their 470 MHz analog trunked system.

 

[chgomonitor]

ARINC 800 Mhz Trunked System Control Channels

The system does employ a control channel. I've never bothered to determine which exact freqs from the pool serve as control channels. Also, it's a type one system - so you need to program the fleet map. The fleet map I've posted is as close to what I can figure out as accurate as possible.