Tone Frequency Selection; Tone Squelch (Ctcss) - Kenwood TM-221A Instruction Manual

4-7. TONE FREQUENCY SELECTION
(TM-221A/321A/421A/521A only)
1. To select the Tone Frequency press the M.IN key
and then the TONE key. The Display Panel will
indicate a Tone Frequency. Whenever the M.IN
key is pressed, the M indicator will turn on. You
must complete the desired action within 5
seconds, or the M indicator will turn off. If the in-
dicator goes off, you must press the M.IN key
again.
2. Select the desired Tone Frequency using the
UP/DWN switches on the microphone or the
TUNING control.
Available CTCSS Tone Frequencies
Hz Hz Hz
67.0 114.8 192.8
71.9 118.8 203.5
74.4 123.0 210.7
77.0 127.3 218.1
79,7 131.8 225.7
82.5 136.5 233.6
85.4 141.3 241.8
88.5 146.2 250.3
91.5 151.4
94.8 156.7
97.4 162.2
100.0 167.9
103.5 173.8
107.2 179.9
110.9 186.2
3. Press any key or the PTT switch on the
microphone to return to the receiver frequency
display. A tone will be transmitted whenever the
PTT switch is depressed.
4-8. TONE SQUELCH (CTCSS)
(TM-221A/321A/421A/521A only)
4-8-1. Tone Squelch Operation Initiated by the Dis-
tant Station.
Note:
This function requires the use of the optional TSU-5
Programmable Tone Decoder Unit.
This function allows you to remain squelched until
the proper Tone Frequency is received. If you are on
a busy repeater this can be quite an aid.
1. Press the CTCSS key. The CTCSS indicator will
light in the Display Panel.
2. Your radio will now remain squelched until the
proper code is received. You should ensure all
the stations you wish to communicate with use
the same Tone Frequency. Please note that the
97.4 Hz Tone does not function for decode pur-
poses. Please see Section 4-7 TONE FREQUEN-
CY SELECTION for programming the CTCSS
Tone Frequency.
3. To release the Tone Squelch function (normal
noise activated squelch), press the CTCSS key
again. The CTCSS indicator should go out on the
Display Panel.
4-8-2. To Open the Tone Squelch of a Distant Sta-
tion
Even if the optional TSU-5 Programmable Tone
Decoder Unit is not installed, your radio can open the
Tone Squelch of a distant station.
1. Press the CTCSS key. The CTCSS indicator will
light in the Display Panel.
2. Select the same Tone Frequency between the
stations you wish to communicate. See Section
4-7 TONE FREQUENCY SELECTION.
Press the microphone PTT switch.
To release the Tone Squelch function, press the
CTCSS key again. The CTCSS indicator should
go out on the Display Panel.
PS