US Marshalls freq

[SCPD]

comfirming 170.800 in Central Alabama ( montgomery) heard p25 ENC this date

 

[SOFA_KING]

comfirming 170.800 in Central Alabama ( montgomery) heard p25 ENC this date

Confirming as USM? Did you get a NAC?

Phil

 

[SCPD]

Confirming as USM? Did you get a NAC?

Phil

no nac with Pro 96, I should have my 197 in the next Month or so, waiting for an F&F discount hhe

 

[SCPD]

no nac with Pro 96, I should have my 197 in the next Month or so, waiting for an F&F discount hhe

at least I thought it was what was posted here as being for USMS

 

[SOFA_KING]

at least I thought it was what was posted here as being for USMS

Roger on the 197. Good scanner with an FM broadcast band filter in line.

I have heard USM use this a long long time ago here in FL. I believe it was the input to 162.7125, but this is also a place where some Prison stuff is as well as ICE, and every location may be different, so you need a little more to go on. The NAC helps.

Phil

 

[SCPD]

Roger on the 197. Good scanner with an FM broadcast band filter in line.

I have heard USM use this a long long time ago here in FL. I believe it was the input to 162.7125, but this is also a place where some Prison stuff is as well as ICE, and every location may be different, so you need a little more to go on. The NAC helps.

Phil

ok, I got from here & I thought someone had already verified as b USMS?? oh well

Paul

 

[BalunKnot]

if i remember correctly someone told me they used the INS systems, which may have been what was also referred to above asDOJ system.

 

[sflmonitor]

if i remember correctly someone told me they used the INS systems, which may have been what was also referred to above asDOJ system.

The following pertains to Florida only: While the USM did have some INS frequencies programmed in their radios, it was only for task force activities (INS agents also had some USM frequencies in their radios as well). The INS system was not their primary one.

 

[rvictor]

I'm new to digital scanning, having just gotten a 396XT this week. I've programmed in a number of the frequencies mentioned in this thread and set them for "All" audio. From time to time throughout the day, the scanner will stop on one of the frequencies and I will hear a sound like an open squelch, but no intelligible transmission.

Is this because the frequency is in use but encrypted, or am I doing something wrong in my setup which prevents me from hearing these transmissions?

I don't mean to hijack the thread, so if this requires more than a quick answer, just let me know and I'll start a separate thread.

Thanks.

Dick

 

[SOFA_KING]

I'm new to digital scanning, having just gotten a 396XT this week. I've programmed in a number of the frequencies mentioned in this thread and set them for "All" audio. From time to time throughout the day, the scanner will stop on one of the frequencies and I will hear a sound like an open squelch, but no intelligible transmission.

Is this because the frequency is in use but encrypted, or am I doing something wrong in my setup which prevents me from hearing these transmissions?

I don't mean to hijack the thread, so if this requires more than a quick answer, just let me know and I'll start a separate thread.

Thanks.

Dick

No problem, and congrats on the new scanner!

What freqs are you hearing this on? How strong is the signal (bars?) Collect and present any PL or NAC you get so we can have something to go on. That info is the stuff to grab!

It is possible your squelch is opening due to being set too low. It is also possible you are picking up analog encryption. Analog encryption (DES-XL) has a high pitched squeel at the end of the transmission, so if you are hearing that, you know what it is.

Give us more info! I wonder if USM has any analog left in any area of the country.

EDIT: I'm in the midle of a screaming band opening to my south! Outragous strong signals and quiet noise floor. Even DTV DX is good! Lots of new stuff to follow.

Phil

 

[rvictor]

No problem, and congrats on the new scanner!

What freqs are you hearing this on? How strong is the signal (bars?) Collect and present any PL or NAC you get so we can have something to go on. That info is the stuff to grab!

It is possible your squelch is opening due to being set too low. It is also possible you are picking up analog encryption. Analog encryption (DES-XL) has a high pitched squeel at the end of the transmission, so if you are hearing that, you know what it is.

Give us more info! I wonder if USM has any analog left in any area of the country.

EDIT: I'm in the midle of a screaming band opening to my south! Outragous strong signals and quiet noise floor. Even DTV DX is good! Lots of new stuff to follow.

Phil

Thanks, Phil.

I noted this again today on 167.2125, 167.375, 167.725, and 170.7125. I had the squelch set to maximum to make sure that wasn't the problem. I didn't notice any high pitched squeal at the end of the transmissions. I was unable to note either NACs or PL codes since in the "All" setting for the audio neither can be searched on my scanner. When I reset these frequencies to Digital and NAC search, I no longer heard the noise that I described. The frequencies were then silent all afternoon.

The only thing that I've heard on any of the "federal" frequencies today other than this open squelch sound was on 165.375 on which I heard a warbling sound for perhaps 30 seconds.

Thanks for your help.

Dick

 

[Squad10]

Thanks, Phil.

I noted this again today on 167.2125, 167.375, 167.725, and 170.7125. I had the squelch set to maximum to make sure that wasn't the problem. I didn't notice any high pitched squeal at the end of the transmissions. I was unable to note either NACs or PL codes since in the "All" setting for the audio neither can be searched on my scanner. When I reset these frequencies to Digital and NAC search, I no longer heard the noise that I described. The frequencies were then silent all afternoon.

The only thing that I've heard on any of the "federal" frequencies today other than this open squelch sound was on 165.375 on which I heard a warbling sound for perhaps 30 seconds.

Thanks for your help.

Dick

I suspect that you are receiving FBI voice encrypted transmissions. It is most likely Motorola (DVP/DES or varient) Securenet voice privacy, from what you describe. The body of the message sounds like open squelch on a radio that is not connected to an antenna. The tell tale high pitched squeal at the end of the transmission that Phil mentioned is only a few hundred milliseconds long so you may have missed hearing it. The high pitched squeal tells the receiving radio that it is the end of transmission.

Your scanner will only output audio for this type of signal if in a mode that will only pass carrier squelch.

Listen to http://www.kb9ukd.com/digital/des.wav If you listen carefully, you can hear the high pitched tone at the end of the audio sample.

165.375 is a well known Secret Service frequency.

 

[rvictor]

I suspect that you are receiving FBI voice encrypted transmissions. It is most likely Motorola (DVP/DES or varient) Securenet voice privacy, from what you describe. The body of the message sounds like open squelch on a radio that is not connected to an antenna. The tell tale high pitched squeal at the end of the transmission that Phil mentioned is only a few hundred milliseconds long so you may have missed hearing it. The high pitched squeal tells the receiving radio that it is the end of transmission.

Your scanner will only output audio for this type of signal if in a mode that will only pass carrier squelch.

Listen to http://www.kb9ukd.com/digital/des.wav If you listen carefully, you can hear the high pitched tone at the end of the audio sample.

165.375 is a well known Secret Service frequency.

Squad10,

Thanks very much. That's extremely helpful. The wav file sounds like what I've been hearing and I had to listen to it a number of times before I even heard the high pitched squeal. Perhaps my high frequency hearing ain't what it used to be I could certainly have missed hearing it on the radio. Now that I know what it sounds like I can specifically listen for it to confirm that's what I'm hearing.

That also explains why when I reset the Audio to "Digital" the sound no longer shows up since, as I understand it, it is no longer looking only for just a carrier but also a digital signal that it can decode.

So would I be correct that I should set these "federal" frequencies on which I hear this sound to digital and the NAC to search to maximize hearing any transmissions that might be in the clear and yet to avoid hearing the open squelch noises? I guess I should leave others on All in case they are still using analog. Is this the best bet?

Thanks!

73
Dick

 

[FFPM571]

Chicago USMS field office uses mostly Nextel for day to day communicatons. They will use XTS5000's for tactial use

 

[mike_s104]

Where I am, the US Marshals use the statewide P25 trunked system.

 

[MOTOROLANUT]

Usms Wvirp

Hi Mike,
Where sections/locations in the state on the WVIRP are you hearing the USMS activity?

P.

 

[SOFA_KING]

Hint

Squad10,

Thanks very much. That's extremely helpful. The wav file sounds like what I've been hearing and I had to listen to it a number of times before I even heard the high pitched squeal. Perhaps my high frequency hearing ain't what it used to be I could certainly have missed hearing it on the radio. Now that I know what it sounds like I can specifically listen for it to confirm that's what I'm hearing.

That also explains why when I reset the Audio to "Digital" the sound no longer shows up since, as I understand it, it is no longer looking only for just a carrier but also a digital signal that it can decode.

So would I be correct that I should set these "federal" frequencies on which I hear this sound to digital and the NAC to search to maximize hearing any transmissions that might be in the clear and yet to avoid hearing the open squelch noises? I guess I should leave others on All in case they are still using analog. Is this the best bet?

Thanks!

73
Dick

Dick,

Those analog FBI channels use a PL (CTCSS same thing) of 167.9 for "in the clear" transmissions, so program those channels for that tone and you will hear the unencrypted stuff just fine.

As for P25 Digital, you may want to put each channel in twice (I do) to catch either analog or digital. If the system is now analog, put the first of the two channels as analog. If it is digital, do the reverse. This way the scanner locks onto the primary mode of operation first and will eliminate any added delay of the scanner looking for the tone or code on the wrong mode.

And this brings up the whole question of dual mode operation...I have a nice old list of PL tones to go with my recently converted P25 channels so I can program BOTH digital and analog in for each freq, but what about recent finds of new P25 freqs where you have no analog information to go by? What do you do? You could potentially miss traffic IF they were to switch over to analog and you were only programmed for P25 digital, right?

This is what I do...I take the whole list of my fed stuff and "copy" it to the clipboard. Then I "paste" it to my open memory blocks (just add them as new objects) and weed out the duplicates. Then I change all of them to "Search" under "Squelch Mode" with "Mod" set to "Auto". All of these are assigned to the "Skywarn" list. Now I have a way to listen to my regular fed channels without any filter (CSQ Mode) and search for new PL/DPL/NAC codes at the touch of two buttons (FUNC and WX). This is pretty cool!

Of course this is a GRE scanner, so that doesn't translate 100% to the Uniden owners, but I would bet they could do something similar. The concept could be the same.

Phil

 

[rvictor]

Phil,

Your suggestion of programming them twice--once in analog and once in digital--is super. Then I can search for PLs on the analogs and search for NACs on the digital. Until I get a feel for what there is to be heard on those freqs around here, I think this will work well.

I've generally not set PLs on my frequencies (analog only) in the past unless I had interference of some kind on the channel. Then I would either set the PL of the desired user or lockout the PL of the undesired. The lockouts seem to work particularly well at eliminating 2m ham intermod on the Coast Guard freqs. Any reason to set PLs (or NACs) on these FBI, USM, etc. frequencies? Perhaps I'm missing something in the interaction between the analog and digital.

Thanks again for taking the time to help out.

73,
Dick

 

[SOFA_KING]

Phil,

Any reason to set PLs (or NACs) on these FBI, USM, etc. frequencies? Perhaps I'm missing something in the interaction between the analog and digital.

Thanks again for taking the time to help out.

73,
Dick

Yes, one big reason...so you do not hear DES-XL analog encryption.

A few agencies still use it when they are analog. Putting the PL on will filter out the "noise".

As far as NAC goes, I listen them in NAC search mode so I hear anything digital.

Good luck!

73

Phil

 

[CqDx]

Found a new one today!

170.7125 P25 NAC 293 - Courthouse Opeartions in Newark, NJ