GME TX4500S - Manual (Page 14)

PA G E 1 4 I N S T R U C T I O N M A N UA L T X 4 5 0 0 S
Net-Scan group will locate the transmission by
identifying the group’s CTCSS/DCS code and open
their Squelch allowing the transmission to be heard
across the entire group. 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 SCAN key. A
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.
USING THE PRIORITY CHANNEL
WHILE SCANNING
• If your radio is scanning in Open Scan or Net-Scan
mode and you need to use your Priority channel
(for an urgent call or an emergency), briefly press
the PRI 1 key. The scan will be cancelled and the
radio will jump straight to the Priority 1 channel.
When your conversation has finished, press the
SCAN key to continue scanning.
• If your radio is scanning in Group Scan mode
simply press the PTT. The radio will automatically
transmit on the Priority 1 channel. When your
conversation has finished, the radio will resume
scanning 5 seconds after the channel has become
clear.
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/DCS provides 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
CTCSS uses a continuous analogue sub tone while
DCS uses a digitally encoded sub tone. 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. There is no difference in performance or
function between the different tone sets. Both types
are included in the radio to maintain compatibility
with other radio systems.
CTCSS Tone Set
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.
DCS Tone Set
There are 104 DCS tones available (see the DCS tone
chart at the rear of this manual).
To Select a CTCSS or DCS Tone
1. Press and hold the MENU key until the radio
beeps. The CTCSS menu option will be displayed.
2. If ‘CTCOF’ is displayed, CTCSS/DCS tones are
currently switched off (default). To enable CTCSS
tones, rotate the Channel control to the right.
CTCSS tones will be displayed as CTC01 –
CTC50.
3. Continue rotating the Channel control to scroll
past CTCSS tone 50 to access the DCS tones. DCS
tones are displayed as DT001 – DT104.
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