Federal Trunking Discoveries

[IcomIcR20]

Hi all,

While atop Rainbow Mountain near Huntsville, AL I received two federal trunking systems:

1. I did not see any system matching this system ID in the database. It is still good and strong at the base of the mountain so I am thinking it is possibly at the Redstone Arsenal. Their Motorola TRS is still up and very active although everything thus far has been encrypted. I will run Unitrunker on the system to see if there is any activity.

Here's the info on the new P25 system:

Site: 001-002
ID: BEE00-9D4

406.2375 (a)
406.8375 (c)
407.0375 (a)
407.6375 (a)

The site is showing one neighbor:

Site: 001-003
Control Channel: 406.4375 MHz


2. Found a new site for the Tennessee Valley Authority P25 system. It was not super strong and as soon as I started down Rainbow Mountain, I lost reception. Here is the info:

Site: 011-011
ID: 00001-372
NAC: 00B

407.9125 (a)
408.225 (a)
408.5375 (a)
410.1125 (a)
410.625 (a)
410.925 (c)
171.3875 (a)
173.7625 (a)

Some activity was heard in the clear on TG 339.


Any one have any info on these systems such as user/location? I apologize if they have been mentioned before in the forums .

 

[IcomIcR20]

Ok just did a little checking and it seems that the 406.8375 is/used to be on the Redstone Arsenal Motorola TRS. I am hearing the Motorola control channel on 407.6375 MHz and a P25 control channel on 406.8375. As I said, both of those frequencies are in the DB as part of the Redstone Motorola TRS.

On the P25 TRS I am getting some voice hits as well. Some of the voice freqs are listed on the Motorola DB page while others are not:

I have this so far:

406.2375 (a)
406.8375 (c)
407.0375 (a)
407.4375
407.6375 (a)
409.275
409.6375

TGs heard in the past few minutes are 197, 853, and 8128. I'll do some more digging and get back to this thread.

 

[ecps92]

Your first set of questions is likely NASA from Redstone ?
Visiting Marshall
Since many of those same channels are also showing as used in TX and FL for NASA, it could be an option

 

[ecps92]

And your TVA is likely Browns Ferry nuclear plant
They use a VHF/UHF TRS

 

[IcomIcR20]

Ok I am gathering more details on the Redstone systems. The P25 system doesn't have much traffic but interestingly both the Motorola system at Redstone and the P25 system share the same "pool" of four control/alternate control channels while the voice frequencies for each system are different.

I am collecting my findings and will post them here soon.

And your TVA is likely Browns Ferry nuclear plant
They use a VHF/UHF TRS

Ok thanks! That sounds like a good bet since I can't hear the system at all on the east side of Rainbow Mountain. I won't be able to get over there and confirm that this is where site 11 is, but do you think it's okay for me to go ahead and submit it?

Thanks!

 

[ecps92]

The key was the combination of VHF/UHF in the TRS

I would narrow it down first, maybe confirm a location from actually hearing audio
or do a Close-Call and remove the Antenna to verify.

Submissions need to be right, not fast

Ok thanks! That sounds like a good bet since I can't hear the system at all on the east side of Rainbow Mountain. I won't be able to get over there and confirm that this is where site 11 is, but do you think it's okay for me to go ahead and submit it?

Thanks!

 

[IcomIcR20]

Ok here's what I've got for the two Redstone systems:

So what I have found after closer inspection is that the Motorola and P25 trunked systems at Redstone share the same pool of four control/alternate control channel frequencies. In other words, the control and alternate control channels are the same for both systems, but the voice frequencies are different.

So, at any given time, of the "pool" of four potential control channels, one frequency is carrying the Motorola control channel and another frequency is carrying the P25 control channel while the remaining two frequencies are unused and are listed as alternate control channels on both systems.

Here is the full data for the MOTROLA system. As you can see, it does differ from what is in the DB a little:

NAC: 1B7
Site: 1
System: Motorola A41B
Connect tone: 138.46

406.2375 (a)
406.4375
406.8375 (a)
407.0375 (a)
407.2375
407.6375 (c)
407.8625
408.0875
409.025


And this is the data I have for the P25 system:

NAC: 9D2
Site: 001-002
System: APCO P25 BEE00-9D4
Neighbor: 001-003; CC=406.4375

406.375 (a)
406.8375 (c)
407.0375 (a)
407.4375
407.6375 (a)
409.275
409.6375

So far, I have only heard activity during the day... I let unitrunker run for a good while last night without a single affiliation or key-up. It is fairly active now at mid-morning.

TGs heard: 201, 533, and 837

As far as I have noted in my monitoring, both systems are fully encrypted.

 

[IcomIcR20]

The key was the combination of VHF/UHF in the TRS

I would narrow it down first, maybe confirm a location from actually hearing audio
or do a Close-Call and remove the Antenna to verify.

Submissions need to be right, not fast

Someone else will have to do that, I am just visiting the area. I did hear some in-the-clear traffic on TG 339 in the short time I was able to monitor the system if that helps any.

 

[ecps92]

Make sure, you submit a DB update for the Connect Tone and NAC are not in the RRDB

 

[IcomIcR20]

A DB update for the Motorola system has been submitted. I'll gather as much on the P25 system as I can before submitting it (it may have to be listed as an unknown federal system until someone with more time and more knowledge of the area can somehow pin down a user) .I can't get on the arsenal of course, but I am pretty sure that the P25 system is also on Mt. Madkin as it matches the Motorola system in signal strength at my location.