I'm not familiar with your area at all, but after poking around the database a bit I highly suspect your Unified Fire units are operating on this system:
Utah Communications Authority Trunking System, Various, Multi-State - Scanner Frequencies
Scroll down to Salt Lake County Fire/EMS and you'll see a bunch of Tac channels for them. My guess would be their comms when responding to the call by your house were carried out on one of those Tac channels, or possibly one of the other channels in those listings for Salt Lake County Fire/EMS. If that is where they operate then I think that explains why you heard nothing on the Fire frequencies you downloaded from Sentinel, because what you downloaded were likely the VHF and/or UHF conventional frequencies listed in the database. It's likely those conventional frequencies are not in use any longer. To receive your fire units you would need to have most likely the Salt Lake Simulcast site enabled in your radio, and perhaps one or two other sites for your area. And of course be scanning the relevant talk groups. The P25 system for Unified (or was it United?) that someone linked to looks like a new system that is not online yet, but they may switch over to it at some point in the future. I would get it programmed in your radio and scan it in ID Search mode so you can keep an eye on what's happening with it.
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Utah Communications Authority Trunking System, Various, Multi-State - Scanner Frequencies
Scroll down to Salt Lake County Fire/EMS and you'll see a bunch of Tac channels for them. My guess would be their comms when responding to the call by your house were carried out on one of those Tac channels, or possibly one of the other channels in those listings for Salt Lake County Fire/EMS. If that is where they operate then I think that explains why you heard nothing on the Fire frequencies you downloaded from Sentinel, because what you downloaded were likely the VHF and/or UHF conventional frequencies listed in the database. It's likely those conventional frequencies are not in use any longer. To receive your fire units you would need to have most likely the Salt Lake Simulcast site enabled in your radio, and perhaps one or two other sites for your area. And of course be scanning the relevant talk groups. The P25 system for Unified (or was it United?) that someone linked to looks like a new system that is not online yet, but they may switch over to it at some point in the future. I would get it programmed in your radio and scan it in ID Search mode so you can keep an eye on what's happening with it.
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