![background image](http://html.mh-extra.com/html/icom/ic-440/ic-440_instruction-manual_612149030.webp)
26
6
TONE SQUELCH OPERATION
■
Tone squelch operation
The transceiver is equipped with 51 CTCSS tone frequencies,
104 DTCS codes. CTCSS/DTCS operation provides com-
munication with silent standby since you will only receive calls
from group members using the same CTCSS tone frequency/
DTCS code.
NOTE:
Channels 5 and 35 are used for the emergency
channels, and CTCSS/DTCS operation is not available on
these channels.
D
Setting CTCSS tone frequency/
DTCS code
q
Select the desired channel except for channels 5 and 35.
(p. 14)
w
Push and hold
F
SET
(Set Mode)
for 2 sec. to enter set mode.
e
Push
F
SET
* or
MONI
T SQL
* several times until “
C
” appears.
r
Push
SCAN
TAG
*
to toggle the CTCSS tone frequency/DTCS
code setting mode.
t
Push
or
to set the desired CTCSS tone fre-
quency/DTCS code.
y
Push and hold
for 2 sec. to turn the power OFF, or
push and hold
F
SET
(Set Mode)
for 2 sec. to exit set mode.
*Regardless of the assigned key function.
• Available CTCSS tone frequency list
(Hz)
NOTE:
The transceiver has 51 tone frequencies and con-
sequently their spacing is narrow compared with units
having 38 tones. Therefore, some tone frequencies may
receive interference from adjacent tone frequencies.
[
CTCSS tone setting mode
DTCS code setting mode
DTCS code
CTCSS tone freqnency
List number (grey line)
List number (grey line)
Freq.
67.0
69.3
71.0
71.9
74.4
77.0
79.7
82.5
85.4
88.5
91.5
No.
01
02
03
04
05
06
07
08
09
10
11
Freq.
94.8
97.4
100.0
103.5
107.2
110.9
114.8
118.8
123.0
127.3
131.8
No.
12
13
14
15
16
17
18
19
20
21
22
Freq.
136.5
141.3
146.2
151.4
156.7
159.8
162.2
165.5
167.9
171.3
173.8
No.
23
24
25
26
27
28
29
30
31
32
33
Freq.
177.3
179.9
183.5
186.2
189.9
192.8
196.6
199.5
203.5
206.5
210.7
No.
34
35
36
37
38
39
40
41
42
43
44
Freq.
218.1
225.7
229.1
233.6
241.8
250.3
254.1
No.
45
46
47
48
49
50
51
IC-440-1.indd 26
IC-440-1.indd 26
2008/06/25 15:59:38
2008/06/25 15:59:38