NAC

[TedTobias]

Hi,
What is NAC, I noticed it in my SDS 200 settings And what is it used for?

Thanks so much!
Theodore

 

[sonm10]

It is like ctcss or dcs tones on analog only for p25. Nxdn will have ran or area and dmr will have color codes

If unfamiliar with these codes, they allow multiple users access to the same frequency and mode of operation using different codes. There will still be interference, though.

 

[TedTobias]

Thank so much. where do you get the codes from?

Theodore

 

[bobruzzo]

Thank so much. where do you get the codes from?

Theodore

If you have an SDS200 (like me) it will automatically display NAC code when scanner stops on a P25 transmission. To make sure, go to SETTINGS>Site NAC Operation>Use site NAC
If you use Sentinel or whatever software to program scanner you can also set individual NAC's for stand alone (Not trunked) P25 freqs. For example my state (RI) is on a P25 simulcast system. But my hometown Police doesn't use it. They are on their own 482 Mhz P25 system. So the NAC on their frequencies is different from the state system.

 

[n1chu]

Sonm10’s comment “There will still be interference, though.” relates to the use of the same frequency. Although differing NAC’s may be used, a signal can be present but ignored by your scanner because it’s not using the same NAC as your scanner. This signal, although intelligible with the proper NAC, will have the same effect as a high noise floor on the frequency. What this means to us is this... there may be times when we don’t receive a transmission as clearly as usual, and start thinking there is something wrong with either the transmission or our scanner, when all it amounts to are two signals using the same frequency at the same time.

Thanks to Somn10 for mentioning this. It’s another instance (there are a few) that can create confusion, especially with a newbie who just plunked down hundreds of dollars on a state-of-the-art scanning receiver only to find it’s not performing as advertised, at least in their minds... when all it was is just another instance of a lack of knowledge on how things work. There is nothing wrong with the scanner in situations such as this.

 

[sonm10]

Thank so much. where do you get the codes from?

Theodore

Depends on type of system. For conventional frequencies it will be in the tone column. For trunk systems it is a little more hidden and in the site information. Click on the site name will reveal site information

 

[fxdscon]

Hi,
What is NAC, I noticed it in my SDS 200 settings And what is it used for?

Thanks so much!
Theodore

NAC - The RadioReference Wiki

wiki.radioreference.com