T X 3 5 5 0 S
I N S T R U C T I O N M A N UA L
PA G E 1 9
CTCSS AND DCS
The standard Squelch system is fine for quieting the radio
in most applications. However, it operates solely on signal
strength which means that it will always open to any signal
that is strong enough. If the channel is busy with other
stations the Squelch will be constantly opening making it
difficult to determine which calls are meant for you.
CTCSS (Continuous Tone Coded Squelch System) and DCS
(Digital Coded Squelch) are similar Squelch quieting systems
that provide selective audio muting using sub-audible
signalling. When enabled, only signals with a matching
sub-tone will be heard in the speaker. This effectively creates
a channel that is silent to all traffic except those you wish
to hear.
Choosing CTCSS or DCS
The CTCSS system uses 1 of 50 low frequency tones to open
and close the Squelch on the radio. The DCS system is similar
to CTCSS but uses 1 of 104 digital codes to control the
Squelch. There is no difference in performance or function
between the different tone sets so choosing which tone
system to use will largely depend on the other radios you talk
with. If others already use CTCSS or DCS, you should select
the tone system that matches theirs. If the users you talk to
don’t currently use CTCSS or DCS then you can make your
own choice. Both types are included in the radio to maintain
compatibility with other radio systems.
CTCSS Tone Set Compatibility
The GME CTCSS tone set comprises a table of 50 tones made
up of the standard CCIR-38 Tone Set plus an additional 12
tones added to the end. If communicating with other brands
of radios that only use the CCIR-38 tone set, please select
from one of the first 38 tones to ensure compatibility with
these radios.
If communicating with other GME radios, you may choose
from any of the 50 tones. However, please refer to the
tone set tables listed in each radio’s Instruction manual
for compatibility because, although the same 50 tones are
available in all GME radios, the tones used in older GME
models may be listed in a different order to those in
your radio.
To select a CTCSS or DCS code
1. Press
MENU
to enter the menu. ‘CTCxx’ or ‘DTxxx’ will be
displayed.
2. Press the or to enable CTCSS/DCS and select a
suitable CTCSS or DCS code.
• To select a CTCSS tone, select from ‘CTC01’ to ‘CTC50’
(CTCSS tones 01 to 50).
• To select a DCS code, scroll past CTC50 to select from
‘DT001’ to ‘DT104’ (DCS codes 001 to 104).
• To switch CTCSS/DCS off, select ‘CTCOF’.
Press
CTCSS Off
CTCSS Tone 50
DCS Tone 104
Press
3. To see the actual sub tone instead of the tone table,
briefly press
LEVEL
key. For CTCSS tones the tone
frequency will be displayed in Hz. For DCS codes the code
will be displayed. Press the
LEVEL
key again to return to
the CTCSS/DCS label (refer to the CTCSS and DCS tone
charts later in this manual).
CTCSS
Label
CTCSS Sub Tone
Frequencey
When finished briefly press the
PTT
to exit the menu.
NOTE:
The tone you select will be used for all channels that
have ‘Silent’ enabled.
