System Discovery Noob

[KI5IRE]

I am pretty new at discovering news systems to scan that haven't yet been posted in the database but I am really interested in learning how it is done.

When looking for the active frequencies for a system, how is this done? There are so many listed under the ULS listing that I don't know if I need to plug all the frequencies listed in or if doing that could have a negative effect.

Specifically, I am trying to discover a few new local DMR systems. For example, this is one of the ones I am trying to discover. This system IS already active and is not outdated as this is a brand new arena. I've only had 1 LCN found so far. ULS License - Industrial/Business Pool, Trunked License - WRCR694 - MULTIPURPOSE ARENA FORT WORTH

I have only been going to the map on the ULS and putting the transmitter frequencies in to my scanner, as shown below.


However I see multiple locations with way more frequencies when I mouse over the circle. Do I need to put these in to the scanner as well? Do I need to try to find LCNs for all of these? Will putting all of them in either negatively or positively effect the programming?

 

[rattlerbb01]

Location 1 should be the 5 possible transmitter frequencies for the DMR system. Those are the LCNs you are looking for and where you focus your efforts.

Location 2 is just the 5 pairs in mobile/portable form to allow user radios to be licensed.

Location 3 is the repeater inputs from the fixed base.

Location 4 is likely direct, non repeated portable channels that can either be for normal ops or chit chat, or serve as a backup to the system should it go down during an event. You would have to be very close to the arena to hear these and identify anything on them.

 

[hiegtx]

I would agree that Location 1 is the site you need to use for verification. But there are several things that muddy the waters for you. First, here in the DFW metro area, these frequencies are usually licensed to multiple users. For the first frequency at location 1, 461.825, there are more than six other users listed in Tarrant County. That page is a little deceiving. For each user, there may be more than one emission code licensed. That page has one listing, for each user, for each emission code. So, a license with both an analog, as well as a DMR authorization, would be listed at least twice. There's not as many for 462.500, but still more than one licensed for DMR. Here's 463.225. If you searched the rest of them, and also checked Dallas County and Denon, you'd likely find other possibles.

I've run into the same thing trying to locate undocumented systems in Dallas County. I was trying to see if I could hear the Southwest Airlines system at Love Field, which is in the database. I could not receive it at home, even though Love is less than 10 miles from me. However, I did stumble upon another, unlisted, system, in Desoto, used at an e-Commerce facility. One of the SWA frequencies is used in the Desoto system. What I've ended up doing, when I want to identify usage, is program the frequencies as conventional, with search for the color code. Then, review the recordings, grouped by Color Code, to see if I can determine what type of operation is using the frequency. Once I narrow down likely users for a given color code, then I'll set it up as a DMR system (if licensed for trunking, though some are not licensed as a TRS, but are using the frequencies that way). Once I think I have a DMR system created, then I'll run LCN Finder ans System Status.

Identifying LCNs can be hampered by the amount of usage. If very low activity, then you may not find all the included LCNs, a only the first couple of frequencies are used. If you have too much activity, then that also may affect the LCN Finder.

Once you're confident that the LCNs are correct, then run System Discovery, which will collect audio files of transmissions for each active TGID found. Listening to a string of recordings, for the same TGID, can be more helpful than bouncing back and forth, listening to all the talkgroups.

 

[fwradio]

Were you seeing CH 3/4 on 462.5000? That's what I see when I park across the street from it at the Dairy Queen.

 

[fwradio]

https://www.radioreference.com/apps/db/?sid=10529

Also seeing a Channel 1/2 pop up but never caught which frequency it is on. TG 12 was popping up on it and it was being reported on the 3/4 channel.

 

[KI5IRE]

I'm back to trying to discover new systems. Just want to clarify, in the FCC ULS Database, when trying to plug in a a new system in Sentinel, for conventional and for trunked, all I need is the frequencies from the fixed location, correct?

 

[jason51]

There are tons of DMR systems in both Dallas and Ft Worth that are not in the database. I find them with a limit search, once I have all the info, I plug it into LCN finder. Works well. Also, there are several capacity plus trunked systems in the area with one channel. for The system talked about above, do an LCN search during a busy time in the system, otherwise it will take a very long time.