Unit IDs

If you have a newer Uniden scanner, like the BC346XT or the BCD396XT and have upgraded to the latest firmware, you can enable the scanner to show Unit IDs on trunked and P25 systems. Here's what that means:

Trunked systems are essentially computer controlled, and every time a user keys their radio, information is transmitted throughout the system, including an ID associated with that specific radio. Newer scanners can decode that information and display it. Knowing what radio is being used can be amazingly helpful while scanning. A few of the systems that you can see this on in the Boston area include the Massachusetts State Police, Cambridge PD/FD, and MassPort.

All of the marked and semi-marked MSP cruisers have an ID number on the license plate, and on the fender of the marked cruisers. If you're listening to them on the scanner, this is the "call sign" that they are using, for example "2133 to Station A" would be the trooper operating this car:

For troops A, C, D and H (and maybe B), this number is also used as the ID (prefaced by a "5") for the radio installed in the car itself. So, while I'm hearing that transmission, my scanner is also displaying UID:i52133. So even if I didn't hear the beginning of the transmission, I can still see that and know which unit is calling. Each trooper also has an ID number, which is separate from his cruiser number. Sometimes you'll hear them use their ID number on the radio when they are calling in to book a report, and they always give it at roll call. These numbers are used as the ID (prefaced by a "4") for the portable radio (the "walkie talkie" that the trooper carries on his belt. If the trooper above, whose ID is 2588, gets out of his car and uses his portable, the display on my scanner shows UID:i42588. Since I don't want to be looking up 2588 every time, I can program that ID into the scanner so it displays something simpler, like "Cruiser 2133".

E Troop (Mass Pike) cruiser numbers are 2 or 3 digits followed by an "E", for example, 120E. The ID numbers for the radios installed in the cruisers all start with a 3, and do not correlate to the cruiser number. For example, 120E is i35946. The portable radios follow the same convention the other troops use, though, so 120E is operated by trooper ID 1670, with portable radio ID i41670.

F Troop (Logan Airport) very rarely operates on the MSP trunked system, and are actually dispatched on the Massport system.

It can take a lot of listening to put together a thorough list of unit IDs for a single system. Besides the multiple radios used by each officer, you have the radios at the barracks, on air wing units, marine units, DCR Rangers, MEMA, etc. It can be very rewarding, though, especially if you like to know a little more detail about what is going on. 

If this is the sort of thing that you think might interest you, the Uniden BC346XT and BCT15X are good units that are priced towards the lower end of the spectrum. If you pick up one of these scanners, or if you have had one and just need help programming it, let me know and I'll gladly put together a programming file for you.

As always, post questions, comments, and concerns and I'll get back to you.