OPP P25 simplex NAC's

[ocscan]

Recently I have noticed that the NAC $D1C seams to be the standard NAC used by OPP for simplex use on both UHF and VHF, at least in Eastern Ontario. Has anyone logged any other NAC's used by the OPP or CISO? FWIW most of the transmissions are encrypted as well.

 

[mikewazowski]

D1C for the OPP and C15 for the CISO channels.

 

[ocscan]

Wirelessly posted (BlackBerry8530/5.0.0.654 Profile/MIDP-2.1 Configuration/CLDC-1.1 VendorID/398)

Thanks, that confirms a couple of suspicions on P25 users in eastern Ontario (VHF simplex).

 

[IdleMonitor]

Just curious. What difference does it make knowing the NAC anyways? To me all that matters whether or not I can listen if it's P25 digital as compared to P25 ENC.

In which case, the SIM channels would have both I suppose as I've heard regular P25 and have seen ENC show up from time to time.

 

[Jay911]

One thing that makes NAC codes useful is the "rule" regarding NAC code on a trunked voice channel. Generally, NAC on a trunked voice channel is the last two digits of the sysid plus a single digit identifying connect tone (essentially a PL code used by the trunking controller). So if you stumbled across a P25 signal and found it had a NAC of 2F1, odds are half-decent that you're listening to a voice channel on Fleetnet Zone 2.

NAC also behaves much like CTCSS or DCS as far as scanners go - if you set your scanner to receive a signal with NAC 293, then if I set my radio up on that same frequency to send NAC 050, you're not going to pick me up. So, in that regard, it's just as useful to know NAC as it is to know CTCSS/DCS.

 

[mikewazowski]

Just curious. What difference does it make knowing the NAC anyways?

Same difference as knowing the ctcss/dcs for the frequency.

 

[exkalibur]

And don't forget it can help you to identify users. Awhile ago I picked up some activity on a CISO simplex frequency with a NAC I didn't recognize. For kicks, I punched in an NRPS frequency. Sure enough, the guys I heard had the same NAC as NRPS. They were both encrypted so it didn't help much, but at least I was able to identify them.

 

[ecps92]

Jay, that rule-of-thumb is only valid on the older [3600] systems, not any of the newer [9600] systems.

One thing that makes NAC codes useful is the "rule" regarding NAC code on a trunked voice channel. Generally, NAC on a trunked voice channel is the last two digits of the sysid plus a single digit identifying connect tone (essentially a PL code used by the trunking controller). So if you stumbled across a P25 signal and found it had a NAC of 2F1, odds are half-decent that you're listening to a voice channel on Fleetnet Zone 2.

NAC also behaves much like CTCSS or DCS as far as scanners go - if you set your scanner to receive a signal with NAC 293, then if I set my radio up on that same frequency to send NAC 050, you're not going to pick me up. So, in that regard, it's just as useful to know NAC as it is to know CTCSS/DCS.

 

[Forts]

A few others I've picked up around the London area, if anyone is interested...

RCMP - $100 & $FED
Sarnia Police - $5BE
FBI (Port Huron, MI) - $160
US Customs & Border Patrol - $001 and $351
Stratford Police - $561
Woodstock Police - $228

 

[Jay911]

Jay, that rule-of-thumb is only valid on the older [3600] systems, not any of the newer [9600] systems.

Fair enough, thanks. Now I have my one thing learned out of the way for today and I can relax

 

[ecps92]

Found out the hard way, when I thought they were all formatted the same Have a Cold One or Two and relax

Fair enough, thanks. Now I have my one thing learned out of the way for today and I can relax

 

[ecps92]

Curious which US CBP Freq's are using $001 & $351 as well as the $160 for the FBI which is usually $167

A few others I've picked up around the London area, if anyone is interested...

RCMP - $100 & $FED
Sarnia Police - $5BE
FBI (Port Huron, MI) - $160
US Customs & Border Patrol - $001 and $351
Stratford Police - $561
Woodstock Police - $228

 

[Forts]

I had US CBP on 163.6750 and FBI on 167.7400 and 170.6250. I also had traffic on 162.8250 with a NAC of $210 which I have tagged as US CBP.... I certainly could be wrong with these, but from the occasional clear activity I've heard on them, the descriptions seem to fit.

 

[ecps92]

167.7400 would be 167.7375

162.8250 is likely BP or ICE and that freq is typically an input

Good Finds.

I had US CBP on 163.6750 and FBI on 167.7400 and 170.6250. I also had traffic on 162.8250 with a NAC of $210 which I have tagged as US CBP.... I certainly could be wrong with these, but from the occasional clear activity I've heard on them, the descriptions seem to fit.

 

[Forts]

Thanks for the info! I will update 167.7400 to the proper frequency.

 

[mikewazowski]

Jay, that rule-of-thumb is only valid on the older [3600] systems, not any of the newer [9600] systems.

Around here the rule-of-thumb is still valid unless the tech's are just programming it up that way.