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channel selector is always disabled regardless of the 
Permanent Lockout or Keypad Lock status. Chan-
nels can then be selected only by direct channel 
select (see Section 3.3). 

•

The volume control is permanently disabled if a 
Volume Up/Down option switch is programmed 
regardless of the Permanent Lockout or Keypad 
Lock status. Refer to Section 3.1.3 for more 
information.

•

There is the option to enable the backlight when a 
key is pressed in the Keypad Lock mode. There is 
also the option when programming conventional 
channels to disable DTMF dialing. 

This radio does not have a squelch control. The 

squelch level is preset during alignment. If the keypad 
programming feature is available (see Section 5.18), 
the squelch level can be changed by the user on each 
conventional analog channel. 

Transmitting can be disabled on each conven-

tional, SMARTNET, SmartZone, and P25 Trunked 
channel so that the channel is monitor-only. When 
transmitting is attempted on a receive-only channel, 
“Rx Only” is displayed and an error tone sounds. 

3.9.1  GENERAL

Each selectable channel can be programmed for 

the conventional (analog or APCO Project 25 digital), 
SMARTNET/SmartZone, or APCO Project 25 digital 
trunked operating mode. For example, Zone 1/Channel 
1 could be a conventional channel, Zone 1/Channel 2 a 
SMARTNET channel, and so on. More information on 
these modes follows.

3.9.2  CONVENTIONAL MODE

This is a non-trunked operating mode which 

accesses independent radio channels. There is no auto-
matic access to several channels. Selecting a conven-

tional channel selects a transmit and receive frequency 
and other channel parameters such as squelch control 
coding. 

Conventional channels can be either standard 

(analog) or Project 25 (digital). With digital operation, 
the DSP (Digital Signal Processor) converts the audio 
signal to digital data which is sent over the air as 
complex tones. Another difference is that analog chan-
nels use Call Guard (CTCSS/DCS) squelch control 
and Project 25 channels use a NAC (Network Access 
Code) and talk group ID codes. 

With Project 25 operation, a NAC is transmitted 

and it must match the NAC programmed in the base 
equipment and the radio(s) being called for communi-
cation to occur. In addition, to receive standard group 
calls, the receiving radio must be programmed to detect 
the transmitted talk group ID code. 

With conventional operation, a busy channel 

condition is detected automatically if the busy channel 
lockout (transmit disable on busy) feature is 
programmed. Otherwise, it must be detected manually. 
An out-of-range condition is not indicated by special 
tones or messages as with SMARTNET operation 
because there is no initial data exchange with the 
repeater that allows this condition to be detected. 
Operating features unique to conventional channels 
are described in Section 5.

3.9.3  SMARTNET/SMARTZONE MODE

This is a trunked operating mode in which auto-

matic access is provided to several RF channels. ID 
codes are used to select what radios are being called 
and what calls are received. Monitoring is performed 
automatically and special messages and tones indicate 
busy and out-of-range conditions. 

SMARTNET and SmartZone operation and 

programming is very similar. Basically, SMARTNET 
operation is limited to a single repeater site and Smart-
Zone operation allows automatic roaming between 
sites. Enhanced SMARTNET/SmartZone features 
include roaming (SmartZone only), telephone, private, 
and emergency calls, Call Alert

™

, and messaging. 

Either analog or digital signaling may be used (digital 
is optional).