Draft 02 - Sep 1 2015
Viking Mobile Radio Operating Manual
5-5
Conventional Mode Features
5.4.4
Disable Call Guard
The Disable Call Guard feature option lets the radio disregard any CTCSS/DCS or NAC/
Talkgroup information on the current channel. This programmable feature is best
described as a monitor mode with no white noise. In analog it is functionally the same as
turning the squelch mode to “normal.” In digital mode it is analogous to checking the
“digital squelch” box when programming the radio. The function can be programmed to
any button and the menu. The mode will stay active though channel changes (between
conventional channels) and during scan. While the feature is active the monitor icon will
be displayed.
5.4.5 Conventional Squelch Adjust
Squelch settings on a conventional analog channel can be changed by the user from -7 to
+7. A menu item or function button can be programmed for squelch adjust. While on a
conventional analog channel without emergency or scan active, the user can select the
programmed button or menu item for squelch adjust. The current squelch setting will
show on the display.
Using the up and down navigation buttons on the mobile radio, or turning the rotary knob
clockwise or counter-clockwise, the user can adjust the squelch setting to a desired level
from -7 to +7. Increasing the value t7 causes the squelch to open sooner for
weaker signals while decreasing towards -7 has the opposite effects. Pressing the select
button will store the new squelch setting and return the user to the main display.
5.4.6
Selective Squelch Code Select (CTCSS / DSC / NAC)
This feature allows the normal transmit and receive Call Guard (CTCSS/DCS/NAC)
programming to be temporarily overridden with a code selected from a preprogrammed
list. It is available if the Squelch Select List option switch and a CTCSS/NAC code list
have been programmed. It is also selectable via the menu and soft buttons (Lightning
Control Head only).
In addition, with the Digital Keypad Microphone, conventional systems can be
programmed for the Keypad CTCSS/DSC feature. Codes can then be selected directly
from the table by pressing the key for the code. For example, to select code 3 from the
table, simply press the “3” key. No other conventional mode functions can then be
assigned to these keys.
The CTCSS/DCS/NAC list is programmed with up to 255 tone (CTCSS) or digital (DCS)
Call Guard codes. Different codes can be programmed for the transmit and receive modes,
and carrier squelch (selective squelch disabled) can be programmed if desired. In addition,
each position can be programmed with an NAC code for use with P25 operation.
