frequency so another talkgroup 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. Following a conversation on a trunked system
using a scanner is difficult, if not impossible. Because when
there's a short break during the conversation you're
monitoring, it’s possible that the talkgroup will be assigned
to a completely different frequency in the trunked system.
This type of scanning is difficult and frustrating.
TrunkTracker III changes this! Not only does your new
BC250D scan channels like a conventional scanner, it actually
follows the users of a trunked radio system. Once you know
a talkgroups 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 its terminology will make trunk
tracking much easier. A glossary of other commonly used
terms is provided in the back. (Refer to the "Glossary of
Terms" section.) But if you're already an experienced scanner
operator, you may want to skip to Programming and
Receiving Digital and Trunked Systems on page 49.
What is APCO Project 25 Digital
Communications?
APCO Project 25 is a modulation process where voice
communications are converted into digital communications.
This conversion is similar to the technology used with digital
mobile phones. There are several types of project 25 systems
available!
- Conventional – one frequency with digital voice.
- Trunked with analog control channel and digital voice –
control channel operates at 3600 baud.
- Mixed Mode – trunked system with an analog control
channel alternating/mixing analog and digital voice
communications.
- Trunked with digital control channel and digital voice.
Control channel operates at 9600 baud. (This type of APCO
P-25 System is not supported with this radio.)
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