Omaha Trunking system

[KG4WHM]

I got my BCD396XT this week. Works great on the ORIN system.
I put the frequenies in as conventional, aswell as P25 standard. I programmed them as conventional in case the system fails then they will use them in conventional mode. I set the NAC to search and got NAC140. What my question is would this be the same NAC when they use them in conventional mode if the system fails.

[SquierStrat]

the system doesnt quite work like that. they dont use frequencies, they use talkgroups.

i would assume if they're system failed, they would no longer be using digital at all, (or any kind of trunking) and if theres no p25, theres no NAC.

the only "backup" frequencies that i know of are analog and use a ctcss tone of 156.7

[KG4WHM]

Originally Posted by SquierStrat

i would assume if they're system failed, they would no longer be using digital at all, (or any kind of trunking) and if theres no p25, theres no NAC.

P25 (IMBE) is not just trunking you can use it in conventional mode, Cass County does. If the system fails it can send out a failsoft signal and the radio will revert to a pre programmed frequency, if they are programmed that way. If the system would fail the repeaters that the trunking system used would become converntional repeaters. I am wondering if anyone knows if the NAC on the repeaters now would be the same or not.

Originally Posted by SquierStrat

the only "backup" frequencies that i know of are analog and use a ctcss tone of 156.7

Those are interop frequencies not back up.

Side not if the system would fail the county fire departments would revert to the old UHF channels.

[Astrak]

I would imagine they would keep the same NAC, I guess there is no way to really know unless you talk to a radio tech or it actually happens. I'd just keep the scanner searching for a NAC on the ones you programmed in for failsoft mode. Unless maybe they figured that coverage issues might happen in which case maybe the failsoft is a just an analog frequency

[IrvingtonVFD43]

ORION has 2 different fail-safe modes.

Site Trunking-Each until is assigned a talkgroup, if there is a system failure, the units are reassigned to certain banks of frequencies within the ORION system, the units will continue trunking, but minus the safety features inbeded into the radios.

Conventional-Each radio will function as if it was operating over a conventional repeater, no trunking, each units are assigned a bank of frequencies. Such as Irvington may have 4 of 20 ORION channels assigned to them vs. where Omaha Police may have 10 frequencies assigned to them within the 20 ORION Frequencies.

I believe all communications remain in CPQSK (P-25) Modulation in both fail safe modes. However I am not certain on that.

[KG4WHM]

Thanks for the info. I thought that the radios would go to conventional mode. Didn't know the system could do site trunking.

[NeFire242]

One would think it would be conv analog especially if its going to be more like a "community repeater" of sorts.

Yup the radio even reads "STRUNK" on it when this happens.

[KG4WHM]

Originally Posted by NeFire242

One would think it would be conv analog especially if its going to be more like a "community repeater" of sorts.

Why?????