You can see into several states, but you may be hearing a system in only one state or wide area. I have never heard of a system that covers several states or known agency areas. Those sound like D of J pool freqs to me, but it could be any one of them. Maybe Marsh by the upper freqs, but could also be "B of I" by the lower. Two of the lowers were confirmed analog "B of I" in my database at one time when I lived up there. RA's used many freqs in the upper portion. The NAC is interesting as it doesn't follow what others are reporting.
I was BIG into searching and database recording this stuff in upstate NY and NYC area in the late 90's and the S. FL area from 92 to 97, and 99 to just a couple of years ago. Things are changing here in FL. As agencies are moving to digital, and some old systems have either moved or are combined. I have a lot to catch up on. I came here looking for advice on a possible new scanner that has NAC. (I could use some advise here...help me out!) Is it only GRE at this point? If so...how good is it? Software for logging NAC hits???
What I do know is that the "B of I" did go P25 here not long ago, and it looks like the system channels did change. They are doing P25 multi-cast on different channels in different areas just as they have always done (A1, A2, A3...). Here in S. FL they had core freqs in the main 167 portion, and then rural RA freqs outside usually up in 168 area and above. They also used to use UHF fixed links here in FL and in NY, but I work at tower sites and T1 equipment carries the encrypted link data now here in FL. What I have also found over the years is that there is a pool of freqs that "D of J" agencies use at their choosing in different areas of the country. What may be "B of I" in one area could be "Marsh" or "I and NS" in another. The PL tones and protocals, as well as radio system design (OTAR or other unique features like MDC1200) would confirm who was who, as well as the rare call sign usually only now using the callsign numbers (ie 300) without letters.
A few years ago my database freq list was nearly full and VERY accurate! I created 1000 channel scan lists and I was just listening to empty channels with software PL tracking looking for ANYTHING new or unknown. We get a lot of tropo openings here in FL, so I really raked em in. I got tapped out with nothing new to discover! The "SS" was the first to go P25 here. No channel changes I could see. Then "AT & F" went, and although they are still on the main channel, I do not know if they have changed others. The old "Marsh" analog went dead a couple of years ago. Some big P25 RPTR is now active on one of the old inputs in the Miami area (170.7500), so that might be them, however and I have not heard much else. I'm sure they're on some other channels as well, but I got too busy at work to continue the hobby. Someone "in the know" mentioned they use "the new D of J system", so that may be it. And what about "D of HS"? Where are they?
I'm getting interested again with all these new changes, but I need better equipment. With the "B of I" now P25, I would like to set up a new software controled system that can capture NAC, PL, DPL, and do the "fill the blanks" type of database thing again. No doubt, things have changed and I need to look at new possible freqs. "Cust" is still analog, but for how long? I don't hear any trunking control channels other than the old UHF stuff up around the Cape. Maybe I should look around more here on this forum and see what I'm missing.
BTW - When comparing info that other people have reported, I find so many errors that I can't believe some people can be so far off. A lot of it is VERY old data that had errors to begin with. These obvious errors keep getting passed onto other lists, and some of it is SO wrong that I discount the whole list. The business of cross user/task force freqs is not to be considdered IMO. What you need to focus on is WHO built the system you are listening to. Who hosts it? And understanding the system is key. I know first hand that cross-agency is always going on. Who cares? You just need to tie the systems together. This hobby is fun when you get it right and understand the systems and how they work. Getting mobile to mobile simplex freqs tied to a system is tough when not on a known output, but that is where NAC and PL come in handy as well as formats and ID's.
That is the hard part, but what a feeling when you "got 'em all".
Then you use one scanner to listen to the "knowns" and another to listen to the "empties".