Federal NAC codes

[n4jri]

Xame for McGuire VA Hosp in Richmond, VA. 293 on everything I'm hearing.

73/Allen (N4JRI)

 

[naSTI]

Just to clarify on the PL to NAC Conversion:

The NAC 156 is the Hex value not a decimal value. Use the correct list of converted NAC values below:

$067h = 0103d
$069h = 0105d
$071h = 0113d
$074h = 0116d
$077h = 0119d
$079h = 0121d
$082h = 0130d
$085h = 0133d
$088h = 0136d
$091h = 0145d
$094h = 0148d
$097h = 0151d
$100h = 0256d
$103h = 0259d
$107h = 0263d
$110h = 0272d
$114h = 0276d
$118h = 0280d
$123h = 0291d
$127h = 0295d
$131h = 0305d
$136h = 0310d
$141h = 0321d
$146h = 0326d
$151h = 0337d
$156h = 0342d
$162h = 0354d
$167h = 0359d
$173h = 0371d
$179h = 0377d
$186h = 0390d
$192h = 0402d
$203h = 0515d
$206h = 0518d
$210h = 0528d
$218h = 0536d
$225h = 0549d
$229h = 0553d
$233h = 0563d
$241h = 0577d
$250h = 0592d

Others:
$293h = 0659d
$F7Eh = 3966d

naSTI

 

[WayneH]

The NAC 156 is the Hex value not a decimal value. Use the correct list of converted NAC values below:

This is a convention I've never seen followed. If anything, it's the reverse. Take the full PL value, drop the decimal point and convert to hex. Or take the digits to the left of the decimal and use them as hex. For example, the FBI and DEA do this such as $167 or $156 (as seen above).

 

[naSTI]

This is a convention I've never seen followed. If anything, it's the reverse. Take the full PL value, drop the decimal point and convert to hex. Or take the digits to the left of the decimal and use them as hex. For example, the FBI and DEA do this such as $167 or $156 (as seen above).

Yeah, that is exactly what this list is all about. But you don't "convert" to HEX, it *is* the absolute HEX value. The other list I saw did also drop the decimal and kept the "left" (most significant) values, except the numbers were assumed DECIMAL. Converting a DECIMAL value to HEX is not the same as converting a numeric HEX to DECIMAL.

For Example:
156(decimal) = 09C(hex), which is not the same as:
156(hex) = 342(decimal).

The list I posted above is absolutely correct, and I have verified the NAC codes to be 156h for DEA, 167h (sometimes) for FBI and 100h for BATF and various other agencies in the NY/NJ/PHL area.

 

[WayneH]

The list I posted above is absolutely correct, and I have verified the NAC codes to be 156h for DEA, 167h (sometimes) for FBI and 100h for BATF and various other agencies in the NY/NJ/PHL area.

Your conversion list is correct for what or even who? What I quoted you saying above are two different things and does not validate the other. FBI, DEA and CBP don't use those hex values because they convert to a relevant decimal value (256d, 342d, etc). That was my point.

The whole hex to decimal conversion and vice-versa is complicated enough for a lot of people; I'm saying keep things simple. If you would have simply said DEA or FBI use "xxx" NAC then it would be.

The common decimal to hex list is relevant since people don't carry around calculators and agencies such as USGS and USDA use that list. When you see someone like Bureau of Reclamation using NAC $455 it makes sense why as it converts to 1109 decimal, not the other way around as your list implies.

 

[naSTI]

Your conversion list is correct for what or even who? What I quoted you saying above are two different things and does not validate the other. FBI, DEA and CBP don't use those hex values because they convert to a relevant decimal value (256d, 342d, etc). That was my point.

The whole hex to decimal conversion and vice-versa is complicated enough for a lot of people; I'm saying keep things simple. If you would have simply said DEA or FBI use "xxx" NAC then it would be.

The common decimal to hex list is relevant since people don't carry around calculators and agencies such as USGS and USDA use that list. When you see someone like Bureau of Reclamation using NAC $455 it makes sense why as it converts to 1109 decimal, not the other way around as your list implies.

Most people who would ever care about NAC codes, would likely be using a PSR scanner that filters/decodes only in hex (at least by default it does, I don't know if the latest firmware allows for either). So if people start converting decimal values to use for NAC filtering on their scanners, the squelch would never open.

Also, if you use other software that allows for displaying/entering NACs in either HEX or Decimal, it absolutely makes all of the difference. This includes Icom Receivers and LMR, Motorola LMR, etc..

On the face of this thread, trace1 had posted a quote of a list containing both values and I wanted to make sure that people were not mislead.

I just wanted to clarify that.

 

[JASII]

Federal NAC Codes

I wanted to resurrect this thread because I have been decoding some federal NAC codes lately and I wanted to to see if others are having similar experiences. I have notices several frequencies where the new NAC code does match the digits before the decimal point of the analog PL. For example, PL 136.5 now NAC $136. I am using a GRE PSR500 to decode NAC codes, but I also have a Uniden Bearcat BCD996T. I am hoping with forthcoming software upgrades that NAC decode will be added. I also found it interesting that the Motorola Quantar repeaters have a maximum number of 8 NAC code capability. HAve any other posters here had the experience of users with multiple NAC codes? I have read some posts that TSA may be using two or more NAC codes, but I don't recall any others that are using multiple NAC codes. Also, does anybody know if the software packages available today will mute P25 ENC audio when controlling the GRE PSR500/600? My Butel ARC996 PRO will do that with the Uniden Bearcat BCD996T under software control, but the Butel ARC500 is for programming only I beleive so far, thus it doesn't have that option.

 

[WayneH]

I also found it interesting that the Motorola Quantar repeaters have a maximum number of 8 NAC code capability.

The Access Code Table maxs out at 16, not 8. It's also possible to use NAC F7F to repeat whatever input NAC is used.

HAve any other posters here had the experience of users with multiple NAC codes? I have read some posts that TSA may be using two or more NAC codes, but I don't recall any others that are using multiple NAC codes.

I run two different NAC's on my 2 meter repeater; it's not difficult to setup. I've seen TSA using NAC's 001 through 004 in simplex mode. I also know of a specific FAA repeater that's setup for about four or so tones.

Also, does anybody know if the software packages available today will mute P25 ENC audio when controlling the GRE PSR500/600?

This is a factor of the radio so no it can't be done.

 

[LarryMax]

If you have the correct NAC for a digital transmission, you will hear the encrypted traffic IF YOU HAVE THE CORRECT KEY LOADED.

SO with that said, and since DATA is being sent with the appropriate key. The information needed to listen to encrypted audio is in the signal...right? The radio must have the correct key to hear and the only way that is possible is with a "handshake" between the 2 radios or multiple radios. The Key is being sent in the transmission.

I remember another thread on here about encryption and people saying it can't be broken. Well if the information is in the transmission...it can't be impossible.

There must be a way to "packet sniff" these communications.

And as always when I post to these types of threads. I know, I know, It's illegal. Yes I really know it's illegal. I don't need the Communications act of 1934 typed out for me.

 

[mikewazowski]

SO with that said, and since DATA is being sent with the appropriate key. The information needed to listen to encrypted audio is in the signal...right?

Wrong.

The key id telling the radio which preloaded key to use is sent.

 

[SOFA_KING]

BUMP: Here a NAC, there a NAC, everywhere a NAC NAC...

This is a great thread!

I hope this gets updated often as I'm about to get back into this hobby. I just found out that NAC is now in GRE scanners, but what about any other scanners? Is Uniden going to offer the NAC feature?

And am I correct in hearing that encoded P25 transmissions are not muted in the GRE scanners? If so, WHY NOT? Who would want to listen to that noise? Doesn't the newer Uniden scanners mute on ENC?


Thanks

Phil

 

[kikito]

BUMP: Here a NAC, there a NAC, everywhere a NAC NAC...

This is a great thread!

I hope this gets updated often as I'm about to get back into this hobby. I just found out that NAC is now in GRE scanners, but what about any other scanners? Is Uniden going to offer the NAC feature?

And am I correct in hearing that encoded P25 transmissions are not muted in the GRE scanners? If so, WHY NOT? Who would want to listen to that noise? Doesn't the newer Uniden scanners mute on ENC?


Thanks

Phil

Seem to me most, if not, all your questions are better suited for the GRE and Uniden forums since they will absolutely "derail" this thread into the usual Uniden vs. GRE battle. Not to mention those questions are answered on a daily basis on the Uniden and GRE forums...

 

[SOFA_KING]

Its just a little question. I want to know what people are using for P25 NAC Fed monitoring. This is a specialty part of monitoring. Most general scanner users don't care about NAC or ENC. Maybe I will start a new thread, but then someone will complain that it has been done many times and I should have searched...well I did that, and I read back several pages here. I still do not have the answers I have been looking for. :roll:

 

[DaveNF2G]

SOFA_KING, it is pretty obvious that this is your first day in RR.com. You should read all of the forums before posting repetitive demands for information. There are already answers to your NAC decoding questions in the GRE and Uniden scanner forums. They appear lower on the screen than this forum, so you haven't reached them yet.

I'm sure that, by the time I reach those forums today, you will have added to your post count there, too.

 

[SOFA_KING]

Well, Dave, you are wrong on both counts. Look at my join date. I have been around a while and have contributed good stuff (straight from actual templates) to the trunking databases. I was very active on Rich's site too. Some of the cool and unique (including NAC) features of the new GRE were suggestions I made during the Uniden development sessions. Uniden didn't think anyone wanted those features and took a pass. GRE must have been paying attention. I have talked with Lindsey about a few hot topics and features as well, so I'm NOT new here or anywhere else (Batlabs ham radio mods included).

I'm not spamming, and I get the point of staying on topic. That I apologize for. Maybe this forum is slow and that is why I'm not getting answers. Or maybe people are too snobbish (are you?) to answer a simple question or two to help someone out. Fed monitoring is not your average scanning. It is a specialty and requires more attention to advanced features as well as protocols and squelch codes. That is why I'm asking here. Perhaps a new topic is in order...And yes, I did read back many pages and read through many threads...hours worth. If I found the answer I would not have asked.

If you can get off your high horse long enough to see you do not know it all, maybe you could learn a thing or two. I have been fed monitoring since the mid 70's and I work in the communications field. A few years back I worked direct for the big M and installed many parts of these systems we love to dig out. I have done some programming on them as well. I plan on contributing much useful data on this topic as soon as I'm equiped with the new tools I need. All I needed was a little help getting updated so I could get started again since my hiatus. :roll:

Thanks for nothing, Dave!

 

[DaveNF2G]

Well, Dave, you are wrong on both counts. Look at my join date.

OK, I could have done that. Mea culpa. However, your messages sounded just like a first-timer. I did not respond until I had seen the same question from you more than once today.

And yes, I did read back many pages and read through many threads...hours worth. If I found the answer I would not have asked.

It is very difficult to distinguish those who can't find answers from those who have not looked. I apologize for lumping you into the wrong category. Perhaps a brief mention of your efforts in your message would have prevented that.

However, the NAC decode feature has been discussed extensively on RR.com, particularly in the GRE Scanners forum. There have also been queries in the Uniden Scanners forum about when or whether Uniden would catch up with GRE on this feature. Ultimately, the new product announcement thread stated right at the beginning that the new Uniden scanners due out in 2009 will have that feature. The information is here.

 

[SOFA_KING]

I'm sorry, Dave. I hate to fight. I will enjoy this area of the forums as soon as I'm back in the game. I hope I can add value to the group here.

I'm heading over to the Scanner forums!

Phil

 

[SOFA_KING]

NAC Confirmation

SE FL "B of I" is using NAC 167 on the Alpha group. I have not heard P25 on the other groups. They are still analog with 167.9.

This system must be in transition. I have all my G freqs programmed up for dual mode with P25 programmed to search NACs. I have a feeling we will be seeing mixed mode for some time.

Phil

 

[KE7JFF]

FPS in Portland, OR uses a NAC of 107

 

[daparker_nyc]

NAC Code 9C5?

Here in NYC, I have a fed frequency of 171.69 (or 171.6875 or something close) plugged in to my scanner which I thought was FBI. It's 100% P25 encrypted. I just bought a Radio Shack Pro-106 (with a NAC search function) and just started seeing the NAC code of 9C5 for transmissions on this frequency. Thus not FBI. Anyone know what Fed agency is using that NAC code?

Doug