Uniden UBCD396T Scanner User Manual


 
Understanding Scanning
22
each group operates on...and this frequency selection
is made each time a user transmits. So, while on a
conventional system queries, replies, and follow-ups
are all on a single frequency, they could each be on
completely different frequencies on a trunked system.
This semi-random frequency assignment made
monitoring such a system impossible prior to Uniden’s
invention of the TrunkTracker scanner.
Not only does your UBCD396T 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 are a new scanner enthusiast, you might 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 are already an experienced scanner operator, you
might want to go to “Programming Motorola Systems”
on Page 59, “Programming EDACS Systems” on
Page 63, or “Programming LTR Systems” on Page 66
now.
Trunking systems divide a few frequencies among
many different users, but the way that each system
does this is slightly different. This section describes
some of the technical data behind Motorola, EDACS,
and LTR trunked radio systems.
While there are different types of Motorola trunking
systems, they all use the same basic trunking method.
The system consists of one control channel (or as
many as 4 per system but only one is active at any
one time), plus one or more voice channels (typically
10, 20, or 28 total channels). When a user presses
Push To Talk (PTT) to transmit, their radio first sends
their talk group information to the control channel.
Types of Trunking Systems
Motorola Trunking