Kenwood TM-451A - Manual (Page 81)

USING CTCSS
CONTINUOUS TONE CODED SQUELCH SYSTEM (CTCSS)
The CTCSS feature is available only when the TSU-8
CTCSS unit is installed.
CTCSS functions by using subaudible tones that are
superimposed by a transmitter on a transmitted signal to
control a receiver’s squelch. When used in combination
with the noise squelch, CTCSS provides a simple
method to selectively choose which stations will be
heard. This transceiver offers a total of 38 standardized
CTCSS frequencies.
Monitoring is less tiring when using CTCSS since you
hear only those stations on a particular frequency that
are transmitting the CTCSS tone that you have selected.
SELECTING CTCSS FREQUENCIES
Refer to the chart of frequencies available and the
procedure for selecting the desired frequency on
page 52.
To switch ON CTCSS, repeatedly press [TONE/CTCSS]
until "CTCSS" appears on the Display. Each press of
[TONE/CTCSS] changes the Display as below:
No indicator -► TONE -► CTCSS
No indicator
Subaudible tone not transmitted
and tone squelch not functional.
TONE Subaudible tone transmitted.
CTCSS Subaudible tone transmitted and
tone squelch functional. This
indicator does not appear if the
CTCSS unit is not installed.
Note:
► When using DTSS or Page with CTCSS, the squelch opens only if
the correct CTCSS tone is received and the received DTSS or
Page code matches the code stored in your transceiver.
If CTCSS and Tone Alert are ON, there is no speaker output
except the alarm tone even if a signal is received with the
correct CTCSS frequency.
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