GME TX3420 - Manual (Page 6)

PA G E 6 i n s t r u c t i o n m A n uA l t X 3 4 2 0
cTcss
ctcss (continuous tone coded squelch system) is a
squelch quieting system that allows several groups of users
to share the same channel without disturbing each other .
it uses a preset sub-audible (very low frequency) tone to
open and close the squelch on your radio . there are up to
50 tones available in two optional tone sets . the system
applies a continuous low-level tone to your transmission
and uses a matching tone decoder to control your receiver’s
squelch . With ctcss enabled, the channel remains quiet
to all incoming signals unless they carry the correct tone .
When a transmission with the correct tone is received, the
squelch opens and remains open for as long as the signal is
present . When the transmission ends, the channel becomes
quiet again . transmissions that do not use the correct tone
will not be heard .
the tX3420 allows ctcss to be enabled or disabled on
individual channels .
Note: the ctcss tone you select will be used for all ctcss
enabled channels in your radio .
moNitoriNg the chaNNel
it is useful to be able to temporarily open your radio’s
squelch to allow you to listen for signals from other ctcss
users outside your group . because their ctcss tone is
different to yours, your squelch would normally remain
closed, preventing you from hearing them . you can use
the sQl key to open the squelch and listen to the channel
to check that it is clear before transmitting . this will help
prevent you from accidentally transmitting over the top
of another transmission .
to monitor the channel
Press the sQl key . if there are no signals present, you will
hear the usual hiss of an empty channel . Press the sQl key
again to restore the squelch to its previous setting .
selectiNg the toNe set
there are two standard tones sets available, one comprising
50 tones and the other comprising 38 tones . both tone sets
are included in the tX3420 to provide compatibility with
other GmE radio systems .
selectiNg the reQuireD ctcss toNe
to pre-select the ctcss tone on your radio, please refer to
the meNu settiNgs on page 16 .
eNabliNg ctcss oN a chaNNel
if a ctcss tone has been selected, it can be enabled on
individual channels .
1 . rotate the channel knob to select the required channel .
2 . Press and hold the sQl key . A high beep will be heard
and ‘silEnt’ will appear on the display .
you may activate ctcss on as many channels as you wish
except channel 5 which is designated for emergency use .
DisabliNg ctcss oN a chaNNel
repeat steps 1 and 2 above . A low beep will be heard and
‘silEnt’ will disappear from the display .
Note: you will not be able to activate ctcss if the ctcss
tone is set to ‘of’ .
Please see the ctcss tone Frequency chart on page 21
scANNING
the tX3420 has a scAn function that allows groups of user
programmable channels to be scanned for signals . channels
can be scanned at 20 channels per second . When a signal
is found, scanning will pause on that channel to allow the
signal to be heard, then resume scanning when the channel
is clear again .
scaN grouPs
the tX3420 features two scan groups - open scan and
Group scan .
open scan
Allows any of the installed channels to be scanned for
activity . if a busy channel is found, scanning will pause to
allow the signal to be heard . once the channel has been
clear for 5 seconds, scanning will resume automatically .
e .g . scanning channels 1-8 in open scan
group scan
Also allows any of the installed channels to be scanned
for activity, but in addition, it also inserts your Priority
channel into the scan sequence . this means that your
Priority channel will be monitored regularly while scanning
to ensure that no calls are missed . Any signals received on
your Priority channel will take precedence over any signals
received on the other channels .
e .g . scanning channels 1-8 with Priority channel 20
in Group scan
2 1 3 4 5 6 7 8
2 1 3 4 20 5 6 7 8 20