User's Manual

20-496 Owner’s Manual Draft Page 53/78
allocated system channels in that trunking system and announces the start of the call on the control
channel. Your scanner uses the control channel data to follow activity on the talkgroups you wish to
monitor.
Traditional conventional radio systems operate using a single radio frequency for each group of radio users,
and in some cases, multiple groups sharing the same radio channel in the same geographical area. This
frequently results in heavy traffic and often requires that radio users wait long periods for the frequency to
clear before they can place their calls. Trunked systems allow large groups of radio users to use radio
frequencies more efficiently. Instead of selecting a specific frequency to transmit on, a trunked system
chooses one of several frequencies when the 2-way radio user transmits. The system automatically
transmits the call on that frequency, and also sends a code that identifies that 2-way radio user’s
transmission on a control channel.
Notes: To receive trunking signals from a trunked radio system, you must:
. Store all the trunking control frequencies for Motorola or APCO-25 systems in one channel storage bank,
or
. Store all the trunking system frequencies for EDACS in one channel storage bank, and
. Configure the channel storage bank ID list for the type of trunking system being monitored, and
. Enter ID codes into the ID memory for the bank
. For detailed trunked system programming instructions, see “Programming Trunked Systems” on Page XX
and “Storing Talkgroup IDs” on Page XX.
Your scanner lets you easily hear both the call and response transmissions for that 2-way radio user and
therefore follow the entire conversation. For Motorola, APCO-25 and EDACS trunking systems, the
scanner monitors the control channel between each transmission to determine active talkgroups.
Your PRO-2096 automatically calculates Motorola and APCO-25 trunking system voice channel
frequencies while decoding the control channel. This eliminates the need to enter all the Motorola system
frequencies.
The control channels for some Motorola trunked radio systems may change on a day-to-day basis. To
ensure that you will not miss traffic when the control channel changes, enter all the known control channel
frequencies into the channel storage bank. If the control channel changes, your scanner will automatically
lock on to the new control channel. If you do not know which system channels are used for the control
channel operation, we recommend that you enter all the system frequencies into the same bank.
Note: Frequency fleet map and talkgroup information are also widely available on the Internet. For example,
at www.trunkscanner.com.
When the scanner decodes the Motorola control channel and finds talkgroup activation on a voice channel,
the scanner displays the control channel memory location on the top line, the received frequency with VC
(voice channel) on the second line, the bank and control channel memory location number on the third line
and the Motorola talkgroup ID number on the bottom line.