Rome Laboratory P25?

[R0am3r]

I found a P25 system on 173.0625 MHz using Close Call (CC). I believe this system belongs to the Air Force Research Laboratory in Rome NY. I verified the P25 system with DSDPlus Fast Lane and it shows NAC=200 and all the users seem to be using Talk Group 1. Whenever I use CC near Rome Laboratory, it often finds activity on 173.0625. Unfortunately, CC never finds the control channel for this P25 system. Does anyone have an idea of how to locate the control channel?

 

[GTR8000]

What makes you sure that it's a trunked system? It could just be a conventional P25 frequency with NAC 200. While conventional P25 is technically capable of talkgroups, it's rare to see them being used, and thus everything defaults to TG 1.

In any case, search between 168-174. If this does happen to be a trunked system, you'll likely find the control channel somewhere in that chunk of spectrum.

 

[R0am3r]

I didn't know there was such a thing as a conventional P25 system. Thanks for the information! I have performed numerous searches of this part of the spectrum using conventional discovery and haven't found anything that sounds like a control channel. I'll give it some more time before I submit it for a new frequency. Also note... some of the transmissions are encrypted. Others are in the clear and they seem to be mobile units. I'll record some more to see if there is anything else to learn from them.

 

[GTR8000]

Conventional simply refers to any non-trunked usage. Could be analog simplex, analog repeated, or the same using digital modulations like P25, DMR/TRBO, NXDN, etc. Standalone conventional non-trunked P25 repeaters are fairly common. As noted in my previous post, nearly all P25 capable equipment defaults to TG 1 unless someone changes it. A TG is required by the P25 spec, although normally they are only employed with trunked systems, not on conventional frequencies, thus the defaulting to 1.

In any event, if you monitor 173.0625 for a period of time and only see TG 1, and are able to fully follow conversations, it's almost certainly not part of a trunked system.

 

[GTR8000]

There is one other instance of 173.0625 with NAC 200 in the RRDB: Camp Peary (CIA Training Facility) in York County, VA. That doesn't seem to be related to what you're hearing lol

 

[GTR8000]

PS - Here's the list of all P25 conventional in the database, starting on the page listing NY (probably need to be logged in as a premium member to view)

https://www.radioreference.com/apps/db/?rpt=5&mode=2&os=5800&sort=6

 

[R0am3r]

Wow - great list. Thank you!

 

[ecps92]

Conventional P25, not a TRS
Been around for sometime, but no one has ever ID'd who it is

$200 is one of the prev known NAC's used by DoE.. and many other FEDS
173.0625 is used by different agencies, ie: not allocated to one specific entity.

See if you can ID them from the audio

Heard loud n clear in the Utica/Syracuse area

I found a P25 system on 173.0625 MHz using Close Call (CC). I believe this system belongs to the Air Force Research Laboratory in Rome NY. I verified the P25 system with DSDPlus Fast Lane and it shows NAC=200 and all the users seem to be using Talk Group 1. Whenever I use CC near Rome Laboratory, it often finds activity on 173.0625. Unfortunately, CC never finds the control channel for this P25 system. Does anyone have an idea of how to locate the control channel?

 

[nacsr]

I also plugged in 173. 0625 when I saw your post. Nothing so far.

 

[studgeman]

It's EADS security forces. P25 conventional, mostly encrypted. As noted, its been around for some time. AFRL Force Protection used to be somewhere in th 164-167 range.

 

[ecps92]

anyone confirm the input ??

It's EADS security forces. P25 conventional, mostly encrypted. As noted, its been around for some time. AFRL Force Protection used to be somewhere in th 164-167 range.

 

[R0am3r]

studgeman - I have been recording the non-encrypted transmissions on 173.0625 for about a week and I pretty sure you are correct - this is likely EADS. Most of the discussions are the security personnel checking in from their mobiles. Overall, pretty boring. GTR8000 - when I added this frequency as a conventional P25, my mobile scanner found it properly during a scan. Thanks for your help.

There is another active frequency (173.4625) near/on Griffiss. This is also a conventional P25 system, NAC=293h. Unfortunately, everything that I have detected on Close Call is encrypted. Could this be AFRL? Until I hear an unencrypted transmission, it is only a guess.

 

[R0am3r]

Strike that. Reverse the last comment. These are indeed AFRL personnel using 173.0625. I listened to them all week and confirmed who they are based on the facilities they are discussing. Maybe the other frequency is EADS? It doesn't matter because 173.4625 is 100 percent encrypted.

 

[studgeman]

Interesting, I have been listening to it for years. I listened to the Lab back when it was analog too. Never would have guessed it was one in the same. I used to work in the vicinity of all of that with a scanner on my desk for 5 years..... Sometimes you just catch it right!