TONE CODED SQUELCH SYSTEMS
TONE CODE FREQUENCY CROSS-REFERENCE
Radio equipment manufacturers use different names or code identifiers to describe the
continuous tone coded squelch systems (CTCSS) used in radio communications equipment. The
various names and code plans sometimes make it difficult for a user to identify his own tone
frequency. For example, Motorola Communications has trademarked the name "Private Line" or "PL"
to describe their tone squelch system and General Electric uses the name "Channel Guard" or "CG."
The tone systems are generally compatible if the tone frequency is the same.
The tone frequencies listed within this booklet are in Hertz (Hz). By using the cross-reference
to convert your tone to hertz, you can determine if your radio is compatible with that of a different
system.
For example, if you operate a Motorola radio and know your Private Line (PL) is "2A" your
actual tone frequency is 114.8 Hertz. You can therefore communicate with any radio system with
the same CTCSS tone.
Code
1
1A
1B
1Z
2
2A
2B
2Z
3
3A
3B
3Z
4
4A
4B
4Z
5
5A
5B
5Z
6
6A
6B
6Z
7
7A
M2
Tone
Code
Tone
100.0 Hz
103.5 Hz
107.2 Hz
100.0 Hz
110.9 Hz
114.8 Hz
118.8 Hz
110.9 Hz
123.0 Hz
127.3 Hz
131.8 Hz
123.0 Hz
136.5 Hz
141.3 Hz
146.2 Hz
136.5 Hz
151.4 Hz
156.7 Hz
162.2 Hz
151.4 Hz
167.9 Hz
173.8 Hz
179.9 Hz
167.9 Hz
186.2 Hz
192.8 Hz
210.7 Hz
7Z
8
8Z
9
9Z
0
0Z
A
AZ
B
BZ
C
CA
CB
CZ
D
XA
XB
XZ
YA
YB
YZ
ZA
ZB
ZZ
M1
186.2 Hz
206.5 Hz
206.5 Hz
229.1 Hz
229.1 Hz
254.1 Hz
254.1 Hz
281.8 Hz
281.8 Hz
312.6 Hz
312.6 Hz
346.7 Hz
358.9 Hz
371.5 Hz
346.7 Hz
384.6 Hz
71.9 Hz
77.0 Hz
67.0 Hz
85.4 Hz
88.5 Hz
82.5 Hz
94.8 Hz
97.4 Hz
91.5 Hz
203.5 Hz
NC UHF MED TONE DESIGNATORS
Code
Tone
A
B
C
D
No Tone
203.5 Hz
103.5 Hz
192.8 Hz
Code
E
F
G
H
I
Tone
127.3
107.2
186.2
167.9
110.9
Hz
Hz
Hz
Hz
Hz