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are taken and then the bits are rotated to determine if a 
valid code was received. 

5.5.5  SELECTIVE SQUELCH CODE SELECT 

(CTCSS/DCS/NAC)

NOTE: Call Guard codes can be permanently repro-
grammed by keypad programming described in 
Section 5.18.

This feature allows the normal transmit and 

receive Call Guard (CTCSS/DCS/NAC) program-
ming to be temporarily overridden with a code 
selected from a preprogrammed list. It is available if 
the Squelch Select List option switch or menu param-
eter and a CTCSS/NAC code list have been 
programmed. 

In addition, 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 (selec-
tive 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 rese-
lected. 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 

Squelch Select List option button or menu parameter:

1. Press the Squelch Select List option switch or select 

the Sqlch Code menu mode parameter. Then press 
the Up/Down switch to select the desired code. The 
display indicates “SEL SQ xx” where, “xx” is the 
selected code from 1-64. The code number and 
actual code are alternately displayed (NACs are 
displayed in hexadecimal).

2. To select the displayed code and return to the normal 

display, press the F2 (Select) key or the Squelch 
Select List switch again. 

3. To check which code is selected, press the Squelch 

Select List switch once to display the current selec-
tion and then again to return to normal operation.

4. To return to the normal selective squelch codes, 

select “DEFAULT” in this mode. As previously 
described, the normal codes are also automatically 
reselected whenever radio power is cycled or a talk-
around channel is selected.

A penalty timer may be programmed on conven-

tional systems to prevent transmissions for the 
programmed time after the time-out timer disables the 
transmitter (see Section 4.3). The penalty timer can be 
programmed for the same times as the time-out timer, 
and timing starts when the PTT switch is released. If 
the PTT switch is pressed during the penalty time, the 
time-out indication occurs again and the transmitter 
remains disabled. When the penalty timer expires, a 
beep sounds and the transmitter can be keyed.

A conversation timer can be programmed on 

conventional systems in addition to the time-out timer 
(see Section 4.3). This timer limits the total length of a 
conversation rather than just the length of each trans-
mission as with the time-out timer. The following is 
more information on this timer.