Huntsville-Madison County Airport Authority TRS

[N8OAY]

Can anyone confirm that the Huntsville-Madison County Airport Authority EDACS system is Standard 9600 baud and analog? I have yet to hear any voice traffic on the system. The PSR-500 stops on what appears to be active talk groups, but there is no audio. The only talk group I have seen it stop on is 6-044 HMCAASecMain.

I have tried to run Unitrunker on the system but it does nothing. I have the correct radio set for Signal only, and the correct com port set, but when I click the start arrow nothing happens.

Thanks for the help!

Edit...I realized I need to configure more settings in Unitrunker, and posted a question on the software forum for help with that.

 

[W8RMH]

I noticed this on the DB page:

The only antenna for this system is on top of the terminal building, therefore it does not have a wide area of coverage.

I used to work at an airport with a EDACS system. It worked well on the airport grounds but get a couple miles away and it was impossible to hear it. You may just be out-of-range.

I also noticed that this system has an emission designator of 14K0F9W.

F9W may indicate it is Harris OpenSky which cannot be monitored by any scanner, past or future.

I have noticed that EDACS systems can be easily upgraded to OpenSky.

 

[N8OAY]

I noticed this on the DB page:

The only antenna for this system is on top of the terminal building, therefore it does not have a wide area of coverage.

I used to work at an airport with a EDACS system. It worked well on the airport grounds but get a couple miles away and it was impossible to hear it. You may just be out-of-range.

I am getting a good signal for the system - 5 bars on the PSR-500 signal strength scale. If the trees were gone, I probably am in line of sight of the antenna. Looking at Google Earth, i live close enough to the airport that the short runway is longer than the distance from the terminal building to my home. And yes, the antenna is low - maybe half the height of the control tower.

Is there any way to confirm if the system is Open Sky instead of EDACS? Listening to the control channel, it sounds like the control channel on the Miami County OH EDACS system.

 

[N8OAY]

Researching the Emission Designator, 14K0F9W indicates 14KHz Bandwidth, FM Modulation, one or more digital channel and one or more analog channel, and a combination of data and voice transmissions. I got this info at Emission Designations - MMI Technical Resource I have never paid any attention to the emissions info before this came up on this system, but that emissions designator appears to me to be pretty generic. I was under the impression that Open Sky was 100% digital.

 

[N8OAY]

Can anyone help determine of this system is actually EDACS Standard Analog, or Harris Open Sky as suggested above, or maybe Provoice or whatever? I am not getting any audio when the scanner stops on a talk group, regardless of which talk group is active. I have seen several talk groups, some that are listed on the RR web page for this system and some that are not. And I have not had any luck getting either Unitrunker or ETrunker to work on this system, which suggests to me that it may be Harris Open Sky. IIRC, Unitrunker and ETrunker both can work on on Provoice systems.

Thanks for the help!

 

[Avery93]

I doubt it is OpenSky, as your scanner wouldn't be tracking the talkgroups or decoding the system at all. Also I don't think it even uses a normal, fixed control channel.

Try listening to the voice frequencies in analog carrier squelch and see if you can hear anything. If you hear digital transmissions, compare it to some of the sound samples on this site under the Digital Voice Formats section, paying particular attention to the Provoice listing. I would also compare the control channel sound to the samples listed under Trunked Radio Systems.

 

[SCPD]

Does the Unitrunker program show any call activity? If so, what service types are shown. Look under the Svc column on the Calls tab. Mobile data will appear as "Dat". ProVoice calls will appear as "Dig". Analog voice calls appear as "Ana".

If you suspect Opensky, tune your discriminator tapped radio to the suspected Opensky channel and look at the Decode section of the receiver window. The program detects the narrow 2 slot version of Opensky. The Protocol field with say "Opensky" in this case. Likewise, the program can detect ProVoice voice channels. Look for ProVoice in the Protocol field.

It's possible you have an EDACS system that is migrating to Opensky. If the older 4 slot version of Opensky is in use, the program won't detect it. The 25khz signal is wider than the filter on most discriminator taps.

 

[N8OAY]

I just figured out what the problem is! This system has rebanded, but it has not been updated on the RR.com listing. I just need to figure out the LCN.
ULS License - PubSafty/SpecEmer/PubSaftyNtlPlan,806-817/851-862MHz,Trunked License - WPJQ537 - HUNTSVILLE MADISON COUNTY AIRPORT AUTHORITY - Frequencies Summary
I was sitting here feeling frustrated as H E Double Toothpicks looking at the RR.com page and realized the frequencies did not look right, and went to the call sign info. The frequency for the control channel 856.9625 is correct on the RR.com listing, but the other 3 frequencies have been changed. I am now getting audio on the BC780XLT. It should not take long to figure out the LCN since there is only 4 frequencies.

I guess I am the only one in the Huntsville AL are that is interested in listening to airport fire/crash trucks and a railroad intermodal yard, since apparently no one else has commented about this system not being able to be scanned...the last date on the FCC license web page is 06/23/2011,

 

[morganAL]

This what I have

Ch 1 - 856.9625
Ch 2 - 854.2625
Ch 3 - 854.8125
Ch 4 - 855.2125

 

[N8OAY]

This what I have

Ch 1 - 856.9625
Ch 2 - 854.2625
Ch 3 - 854.8125
Ch 4 - 855.2125

That is what I am using. It has been a long time since I have heard that "beep...beep...beep beep". At least it is not as bad as the old GE jingle, haha!