What is Trunk Tracking?
Conventional scanning is a simple concept. You enter a radio frequency in your scanner’s memory
which is used by someone you want to monitor. For example, the police in your area may broadcast
on 460.500 MHz , the fire department on 154.445 MHz, the highway department on 37.900 MHz,
etc. So when your scanner stops on a frequency, you usually know who it is, and more importantly,
you can stop on a channel and listen to an entire conversation. This type of scanning is easy and
fun.
As the demand for public communications has increased, many public radio users don’t have
enough frequencies to meet their needs, and this has created a serious problem. Trunking radio
systems solve this problem.
In a trunked radio system, which contains up to 29 different frequencies, radio users are divided into
groups, often called talk groups, and these talk groups are assigned specific IDs. When someone in
a talk group uses their radio, a brief burst of data is broadcast before each transmission. The
trunking system computer uses this data to temporarily assign each radio in a talk group to an
available frequency. If the group using a frequency stops broadcasting or pauses between replies
for a few seconds, they are removed from the frequency so another talk group can use it.
Sharing of the available public service frequencies, or trunking, allows cities, counties, or other
agencies to accommodate hundreds of users with relatively few frequencies. On the other hand,
following a conversation on a trunked system is difficult, if not impossible, because when there’s a
short break during the conversation you’re monitoring, it’s possible that the talk group will be
assigned to a completely different frequency in the trunked system. This type of scanning is difficult
and frustrating.
TrunkTracker™
changes this! Not only does your new
BC895XLT
scan channels like a
conventional scanner, it actually follows the users of a trunked radio system. Once you know a talk
group’s ID, you won’t miss any of the action.
If you’re a new scanner enthusiast, you may want to read the first part of this manual and use your
scanner in conventional mode before you begin trunk tracking. Understanding scanning
fundamentals and terminology will make trunk tracking much easier. If you’re already a
sophisticated scanner operator, you may want to go to
Trunk Tracking
on page 38 now.
6
