User's Manual

20-466 Owner’s Manual
Page 10
You can set your scanner to change the way it receives signals. These settings, called open mode and
closed mode, affect how the scanner receives signals from communications systems that use some type
of closed squelch (such as MOT, and ED systems).
You can set each of the scanner’s channel storage banks to open or closed mode.
In open mode, the scanner scans signals transmitted in all systems. In closed mode, the scanner scans
signals transmitted only under the following conditions:
. When the signals are in the FM mode.
. When the signals are in the MO, or ED mode and the signal’s ID code matches the programmed ID code.
You can also select the users or talk groups you want the scanner to receive in closed mode.
When you set a channel storage bank to open mode, + (open) appears under the bank’s number while
scanning. When you set a channel storage bank to closed mode, - (closed) appears under the channel
storage bank’s number while scanning. Or, OPEN or CLOSED appears while the scanner is in manual
mode or while the scanner is receiving a signal during scanning.
See “Changing the Open/Closed Mode” on Page XX for more information about setting the open and
closed modes.
AM Mode
This sets the scanner to receive transmissions using amplitude modulation (AM). AM is used for aircraft,
military, some amateur radio, and some government transmissions. When the scanner receives a
transmission on a channel set to the AM mode, it always stops on the transmission.
FM Mode
This sets the scanner to receive transmissions using frequency modulation (FM). FM is used for most
public safety transmissions, as well as broadcast, business, and amateur radio transmissions. When the
scanner receives a transmission on a channel set to the FM mode, it always stops on the transmission.
Motorola Mode
You can set your scanner so it decodes the talk group IDs used with Motorola trunking systems. This
setting is called the Motorola mode.
Motorola systems are trunking systems used primarily by business and public safety groups to efficiently
allocate a small number of frequencies (as few as 5) to many groups of users (as many as several
thousand). To do this, each group of users in the system is assigned to a specific talk group. For example,
the east side patrol officers might all be assigned to talk group 2160. One channel in the system is
continuously transmitting data that identifies which talk groups are active on which channel. In addition,
this talk group information is also transmitted as subaudible data on each active channel.