New 9600 baud trunk on 380 MHz band?

[EricCottrell]

Hello,

I seem to be picking up a P25 system on 380 MHz with a 9600 baud control channel..
I did pick up some P25 on 386.2125 and 386.5625. The BC796 can not be set up for 380 MHz.

385.7125 9600 Control ?
386.2125 P25 Voice
386.5625 P25 Voice

73 Eric

 

[ericcarlson]

Via the scan-dc mailing list, there is supposedly a new Department of Defense system coming on-line. Here are the freqs that were posted:

Repeater inputs:
396.1825 396.9875 397.0625 398.1125 398.1375 398.1625 398.1875
398.2125 398.2625 398.3125 398.3375 MHz

Possible repeater outputs
386.1825 386.9875 387.0625 388.1125 388.1375 388.1625 388.1875
388.2125 388.2625 388.3125 388.3375

-Eric

 

[DaveH]

Hello Erics,

Really interesting. Mexico has TETRA on 390MHz. A couple of years ago,
I heard some data signal up here around 392MHz. It could have been a
9600 baud CC, but it disappeared. Could this be some sort of N.A. thing?
Did the digital scanner vendors miss this (while distracted by 700MHz)?

Dave

 

[EricCottrell]

Hello Erics,

Really interesting. Mexico has TETRA on 390MHz. A couple of years ago,
I heard some data signal up here around 392MHz. It could have been a
9600 baud CC, but it disappeared. Could this be some sort of N.A. thing?
Did the digital scanner vendors miss this (while distracted by 700MHz)?

Dave

Hello,

My information is that 380 MHz is being opened up for US Government trunked systems. Current scanners consider UHF to start at 406 MHz.

I searched the 380 range with the BC796 and when it stops at 385.7125 the display alternates between DAT and NFM. Also the voice traffic was unencrypted and appeared to be more like this system is in full operation rather than just testing.
Sure looks like a P25 9600 baud system.

I am wondering if the Pro96 with the control channel dump program can decode this system.

You have my permission to post the information over on the Scan-DC list.

73 Eric

 

[mikey60]

If you get a data listing on this system, I'd be interested in seeing that data...

Mike

 

[EricCottrell]

Hello,

I listened on and off for a few days on the two P25 voice frequencies. Several building numbers were mentioned, like Building 50. The term "Post" is used often. Some of the radio traffic deals with Gate or Parking Lot security.

The term "NCA Police" was used once. I am not sure I heard all the letters correctly.

Most of the traffic appears on 386.5625 Mhz

73 Eric

 

[FPO703]

All we need now is someone in the area with a PRO-96 to get the SY Number and the other information.

 

[Starion]

All I hear is TV intermod and airtraffic control between 380 and 400 MHz. :shock: Maybe I'm too far from the repeaters.

Thanks for the information though.

 

[slalomkayaker1]

Wait... Is this system for Washington DC because the author is from MA?

 

[EricCottrell]

Wait... Is this system for Washington DC because the author is from MA?

Hello,

I am in Crystal City, VA for a few days. I am not getting it real strong and if I use my beam it seems to be strongest toward the NE. Problem is there are bigger buildings that may reflect the signals.

They had a medical emergency with a retired military person about 9:20 PM. The person made it to an emergency room nearby.

Control has a call of "360". Also hear Shepard 1 and Shepard 2.

Searching the web Walter Reed Army Medical Center seems to fit as a possible user. They have a building 2, a building 4, and an Emergency Department.

73 Eric

 

[mstarn]

Setup for PRO 96 (DOD) system

Ok, How do I set this (new DoD 380 MHZ system) system up for a PRO 96? What is the base freq., step, offset, etc.? When I punch in .7125 it defaults to .715. que pasa Since I work near k Street in DC I thought I would try monitoring it for a few days.

 

[mikey60]

Re: Setup for PRO 96 (DOD) system

Ok, How do I set this (new DoD 380 MHZ system) system up for a PRO 96? What is the base freq., step, offset, etc.? When I punch in .7125 it defaults to .715. que pasa Since I work near k Street in DC I thought I would try monitoring it for a few days.

Without a control channel dump or a Pro96Com capture, we don't know for sure.

You could try this...

Base 386.0
Spacing 6.25Khz
Ch lo 8192
Ch Hi 12287
Offset 8192

It's just a guess... It's likely that the Ch lo, Ch hi, and offset are what's shown, just the base and spacing (or step) sizes may be incorrect.

Mike

 

[EricCottrell]

Hello,

Unfortunely I did not have the Pro96 with me so I could not try for a dump.

I got a better signal when I was on the train heading out of Union Station. I was either in the NE part of Washington or in nearby Maryland.

Can you set up the Pro96 for 380 MHz? The BC796 will only accept 406 MHz and higher for UHF.

73 Eric

 

[mlevin]

When entering the control channel on my 96 I get "invalid freq". Even though I have extended frequencies enabled through win96. I'm probably to far away anyways to recieve anything.

 

[blantonl]

Try programming the control channel using Win96

 

[mikey60]

The problems programming this might be due to the hard coding Don Starr was talking about. The Pro-96 may not be able to track this system...

Mike

 

[mlevin]

When programming the freq through win96, the program rounds the freq down to 385.710, instead of the actual freq of 385.7125.

 

[DaveH]

Re: Setup for PRO 96 (DOD) system

Ok, How do I set this (new DoD 380 MHZ system) system up for a PRO 96? What is the base freq., step, offset, etc.? When I punch in .7125 it defaults to .715. que pasa Since I work near k Street in DC I thought I would try monitoring it for a few days.

Without a control channel dump or a Pro96Com capture, we don't know for sure.

You could try this...

Base 386.0
Spacing 6.25Khz
Ch lo 8192
Ch Hi 12287
Offset 8192

It's just a guess... It's likely that the Ch lo, Ch hi, and offset are what's shown, just the base and spacing (or step) sizes may be incorrect.

Mike

First, looks like Mark you have the bank step size set to 5kHz, where it should be 6.25 or 12.5kHz.

Also, do channel numbers in pure Astro systems get that large (offset 8192 etc.)?

Dave

 

[bear105]

I've been getting alot of analog traffic on 386.72Mhz and 386.77Mhz. Its really bad quality though and I haven't been able to nail down the users. I do keep hearing University Street though...Ring any bells??

 

[mikey60]

Re: Setup for PRO 96 (DOD) system

Also, do channel numbers in pure Astro systems get that large (offset 8192 etc.)?

Dave

The Pro-96 doesn't properly handle the identifier tables that are broadcast on a 9600 baud P25 system. If it did you wouldn't have to do anything to track it since all of the information it would need is broadcast by the system.

9600 P25 systems can have up to 16 frequency identifier tables, each with 4096 channels. Since the Pro-96 doesn't handle the identifier tables, you have to work in blocks of 4096 channels. 8192 would be the beginning of Identifier table #2 (0 is usually 800, 1 is usually 764).

Mike