Scanning a trunk systems and PL tones

[NWI_Scanner_Guy]

Seems to me I've seen this question asked somewhere here on RR before, but for the life of me, I can't find a thread along those lines, so I guess I'll toss this question out....

Do trunking systems utilize CTCSS / DCS tones? I'm thinking they don't, but would like to know for sure.

Thanks in advance for any information provided.

 

[oracavon]

No, trunked systems don't use tones. CTCSS and DCS are used on conventional analog channels. Conventional (i.e., non-trunked) P25 digital channels use NAC instead of tones. Trunked systems of either type (analog or digital) don't use tones or NAC.

 

[nd5y]

P25 trunked systems do use NAC on both control and voice channels.
Motorola analog trunked systems use a connect tone on the voice channel inputs only and have a subaudible data on the outputs.
EDACS analog systems have subaudible data that contains an access code on the voice channels.

 

[NWI_Scanner_Guy]

P25 trunked systems do use NAC on both control and voice channels.
Motorola analog trunked systems use a connect tone on the voice channel inputs only and have a subaudible data on the outputs.
EDACS analog systems have subaudible data that contains an access code on the voice channels.

So then, are connect tones and access tones the same as CTCSS/DCS tones?

Sent wirelessly from somewhere behind the Iron Curtain.

 

[nd5y]

No. They are different and irrelevent to scanner users.

 

[NWI_Scanner_Guy]

No. They are different and irrelevent to scanner users.

Cool. Thanks for the clarification.

And a thank you to oracavon for your reply as well.

I appreciate the information.

 

[poltergeisty]

LTR will use sub tones I believe.

 

[nd5y]

LTR uses subaudible low speed data, not tones.

 

[poltergeisty]

Why is it that I can program tones in a two way that is for LTR?

 

[DaveNF2G]

Probably because the repeaters are dual-mode LTR and conventional.

Or maybe the low-speed data averages to whatever tone frequency you have programmed.

The connect tones on a Motorola trunked system work the same way as CTCSS. The frequencies are non-standard and have lower tolerances.