User's Manual

20-527 Owner’s Manual Draft
Page 39 of 60
but the display will alternate between all active IDs.
• Frequency fleet map and talk group information are also widely available on the Internet, (for example, at
www.trunkscanner.com).
Understanding Trunking
In the past, groups that transmit frequently, such as police departments, could transmit on only a few
frequencies. This resulted in heavy traffic and often required 2-way radio users to wait for a specific
frequency to clear before transmitting. Trunked systems allow more groups of 2-way radio users to use
fewer frequencies. 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.
Your scanner lets you easily hear both the call and response transmissions for that 2-way radio user and
therefore follow the conversation. For EDACS and Motorola (above 406 MHz range), the scanner
monitors the control channel between each transmission to identify talk groups. For some Motorola (under
512 MHz range) and LTR systems, the scanner uses the subaudible data sent with each transmission to
identify talk groups.
Setting Squelch for the Trunking Mode
Your scanner automatically mutes the audio during trunk scanning when it decodes control channel data.
However, we recommend you turn SQUELCH clockwise and leave it set to a point just after the hissing
sound stops. This lets the scanner quickly acquire the data channel.
Programming Trunking Frequencies
You program trunking frequencies the same as non-trunked frequencies, except that you must store the
appropriate mode (MO, ED, or LT) with each frequency.
Notes:
• You can scan only one type of trunked frequency, either EDACS, Motorola, or LTR in a bank at one time.
You can, however, mix conventional channels and frequencies in a bank.
• If you are programming trunked frequencies for Motorola Type I and hybrid systems, you must first
program the fleet map (see “Programming Fleet Maps” on Page XX).
• If you are programming frequencies for an EDACS system you must store them in the Logical Channel
Number order (usually listed as LCN#). For example, LCN1 would go into channel 01 for the current bank,
and LCN2 would go into channel 02.
• If you are programming frequencies for an LTR system you must store them in the home repeater order.
For example, home repeater order 1 would go into channel 01 for the current bank, and home repeater
order 2 would go into channel 02.