53SL ES Series Mobile Radio Operating Manual April 2009
6-5
Call Guard Squelch
Section 6 - Conventional Mode Features
6.4.4
Disable Call Guard
A programmable feature lets the radio disregard any CTCSS/DCS or NAC/Talkgroup
information on the current channel. This 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 in
PCConfigure. 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.
6.4.5
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 SQ LIST option switch and a CTCSS/NAC code list have been
programmed. It is also selectable via the menu.
Note
Call Guard codes may be permanently reprogrammed by keypad programming (see
Section 6.14).
In addition, with the Handheld Control Unit (HHC) only, 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 64 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.
When the Call Guard code is changed using this feature, it remains selected even if other
channels are selected. However, if radio power is cycled or a talk-around channel is
selected, the normal codes are reselected. When scanning, the selected code also applies to
all scanned channels. Each channel can also be programmed to always ignore the code
selected from this list and use the default code instead.
If both analog and digital (Project 25) channels can be selected or scanned, the CTCSS/
DCS code for the selected position is used for analog channels and the NAC code for the
selected position is used for P25 channels. If a channel is programmed for mixed mode
operation, the selective squelch type (analog or digital) programmed for the transmit mode
determines the selective squelch type used.
Proceed as follows to select a code using the SQ LIST option switch:
1
Press the SQ LIST option switch and then rotate the Select switch to select the desired
position. The display indicates “SEL SQ xx” where, “xx” is the selected code from 1-
