Ctcss & Dcs - GME TX3120S Instruction Manual

when the transmission ends, all radios in the group
will immediately resume scanning.
If a member of the group responds to the initial
transmission, they will automatically re-use the
same channel as long as the channel remains free
of other signals. this allows the radios in the group
to respond more quickly to further transmissions
from others in the group.
If at any time, a signal from outside your net-scan
group appears on the channel (either with no code
or the wrong code), the channel will be discarded
and a new clear channel will be selected at the
next transmission. the other radios in the group
will then locate the new channel allowing the
conversation to continue seamlessly without any
input from the user.
Ending the Scan
to stop scanning, briefly press the
low beep will be heard and the animated
icon will stop. As long as the radio was not on a
busy channel, it will return to the last channel you
selected, otherwise it will stay on the busy channel.
CtCSS & 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
PA G E 2 4
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
key. A
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. 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 and hold the Channel control to enter the
menu. the display will show the current squelch
level setting.
I n s t r u c t I o n m A n u A l t X 3 1 2 0 s