GME TX4500 User manual

INSTRUCTION MANUAL
DIN size fully featured 5 watt
UHF CB radio

PAGE 2 INSTRUCTION MANUAL TX4500
ACCESSORIES SUPPLIED..............................................3
INTRODUCTION ..........................................................3
IMPORTANT INFORMATION CONCERNING
UHF CB RADIO............................................................3
Possible Issues.....................................................3
Emergency Channels............................................3
Telemetry Channels .............................................4
FEATURES...................................................................4
GENERAL OPERATION.................................................5
Front Panel Controls ............................................5
LCD Panel ...........................................................5
Rear Panel...........................................................5
Microphone.........................................................6
Keypad Functions ................................................6
Volume ...............................................................6
Selecting Channels ..............................................6
Squelch ...............................................................6
Signal Meter........................................................6
Transmitting ........................................................7
Time-Out Timer....................................................7
Backlighting ........................................................7
Bandwidth Filter Settings.....................................7
Dynamic Volume Control......................................8
Voice Scrambler...................................................8
Repeaters and Duplex Mode................................8
Priority Channel...................................................9
Scanning .............................................................9
CTCSS & DCS ....................................................11
Selective Calling ................................................13
Using Selcall......................................................13
Quiet Mode.......................................................15
Group Calling....................................................16
Receive (RX) Only Channels ...............................17
Configuration Menu ..........................................20
INSTALLATION ..........................................................21
Installing the DIN Bracket ..................................21
DC Power Connection........................................22
Microphone.......................................................22
Antenna Installation ..........................................23
Wiring Diagram .................................................23
NOISE SUPPRESSION.................................................23
CTCSS TONE FREQUENCY CHART..............................24
DCS TONE CHART......................................................24
UHF CB OPERATING FREQUENCIES ...........................25
SPECIFICATIONS .......................................................26
SC CONTRACT WARRANTY AGAINST DEFECTS..........27
Contacts................................................back page
CONTENTS

TX4500 INSTRUCTION MANUAL PAGE 3
ACCESSORIES SUPPLIED
TX4500
TX4500 radio
DIN mounting kit
Instruction manual
Microphone
Microphone clip
DC lead
Screw pack
INTRODUCTION
Your GME TX4500 80 channel radio is Australian
designed and built and is the most advanced UHF
Citizen Band radio available. Combining the very
latest in electronic hardware with the most up-to-date
computer aided design and manufacturing techniques
has resulted in a mobile radio with outstanding
specifications and performance.
The TX4500’s DIN sized case allows convenient
installation into a dashboard or console and its strong
die-cast aluminium chassis makes it the most robust
radio of its kind. With just three rotary controls and five
touch keys, the TX4500’s extensive features are easy
to operate.
IMPORTANT INFORMATION
CONCERNING UHF CB RADIO
The use of the Citizen Band radio service is licensed
in Australia by the ACMA Radio communications
(Citizens Band Radio Stations) Class Licence and
in New Zealand by the Ministry of Economic
Development New Zealand (MED). A General User
Radio Licence for Citizens Band radio and operation
is subject to conditions contained in those licences.
The class licence for users and equipment operating
in the CB/PRS 477 MHz band has been amended.
This radio meets the new 80 channel standard.
In simple terms the same amount of spectrum is
available; however, radio transceivers can now
operate in a narrower bandwidth and hence use less
spectrum. These radios are generally referred to as
narrowband or 12.5 kHz radios. By using 12.5 kHz
channel spacing instead of 25 kHz, the 40 channels
originally allocated can now be expanded to 80
channels thereby doubling the channel capacity and
relieving congestion in the UHF CB/PRS band.
Original 40 channel wideband Radios will continue
to operate on the original 40 channels, however they
will not be able to converse on the newer channels
41 – 80. The newer narrowband radios will be able to
converse with all older 40 channel wideband radios
on all channels 1 to 40 as well as the newer channels
allocated from 41 to 80.
The mixing of narrowband and wideband radios in
the same spectrum can cause some possible
operating issues of interference and varying levels of
received volume.
POSSIBLE ISSUES
When a new narrowband radio receives a transmission
from an older wideband radio the speech may sound
loud and distorted – simply adjust your radio volume for
best performance.
When an older wideband radio receives a signal from a
new narrowband radio, the speech may sound quiet –
simply adjust your radio volume for best performance.
Depending on how close your receiving radio is to
another transmitting radio, there can be interference
from the transmitting radio if it is using a channel
adjacent to the channel you are listening to. Simply try
going up or down a few channels from the currently
selected channel.
The above situations are not a fault of the radio but
a symptom of operating wideband and narrowband
radios in the same bandwidth. This possible interference
will decrease over time as the population of wideband
radios ages and decreases.
Further information and updates are available from
the Australian Communications and Media Authority
(ACMA) at www.acma.gov.au and the Ministry of
Economic Development (MED), Radio Spectrum
Management at: www.rsm.govt.nz
EMERGENCY CHANNELS
The ACMA has allocated channels 5/35 for emergency
use only. Channel 5 is the primary Simplex Emergency
Channel. Where a Channel 5 repeater is available, you
should select Duplex on CH 5.
NOTE: Channel 35 is the input channel for the Channel
5 repeater therefore Channel 35 should also not be
used for anything other than emergency transmissions.

PAGE 4 INSTRUCTION MANUAL TX4500
TELEMETRY CHANNELS
ACMA regulations have allocated channels 22 and 23
for telemetry only applications and have prohibited the
transmission of speech on these channels. Consequently
your radio has a transmit inhibit applied to channels
22 and 23.
In the event additional telemetry/telecommand channels
are approved by the ACMA, these channels shall be
added to those currently listed where voice transmission
is inhibited. Currently transmissions on channels 61,
62 and 63 are also inhibited and these channels are
reserved for future allocation.
FEATURES
•
Microprocessor Controlled Frequency
Synthesiser: Allows user programmable control of
scanning, channel memories and selected
feature options.
• Full Spectrum Backlighting: User adjustable,
totally customisable colour backlight settings to
match the vehicle’s dashboard lighting or
drivers preference.
•Digital Signal Processing: Measures, filters and
compresses
standard analogue audio signals and
converts them into digital format. Allows advanced
RF and audio processing techniques to be applied to
maximise the radio’s performance.
•
Advanced Signal Management (ASM): Identifies
interference caused by strong local signals on
adjacent channels and prevents it from opening your
Squelch. ASM also minimises distortion on reception
by fine tuning the receiver frequency to match that of
the incoming signal. This prevents your Squelch from
opening to unwanted interference and ensures that
incoming signals remain clear and undistorted even
when they are slightly off-frequency.
• Dynamic Volume Control (DVC): Automatically
compensates for variations in received audio level
resulting in a constant audio output level to
the speaker.
• Voice Inversion Scrambler
When activated, scrambles your voice so that
communications are only intelligible to others using
the same scrambler technology.
• Programmable Scan Function: Scans the selected
UHF CB channels with both Group and Open Scan
functions available.
• Individually Programmable DUPLEX function:
User selectable for only those individual channels in
your area that have repeaters, leaving the others free
for use as extra simplex channels.
• Priority Channels: Two user programmable Priority
channels allow your working channels to be instantly
recalled at the press of a key.
•
High Contrast Liquid Crystal Display: Fully
detailed LCD provides a visual indication of the
selected channel and all selected functions at
a glance.
•User Programmable Receive-Only Channels:
Use the radio’s front panel controls to program up to
95 of your own receive-only channels (in 5 banks of
19 channels) within the 403-520 MHz
frequency range.
•In-Built CTCSS & DCS: User selectable Continuous
Tone Coded Squelch and Digital Coded Squelch
System option provides silent channel operation on
individual channels.
• In-Built Selcall with Quiet Mode: Provides
selective calling of individuals or groups with fully
user-adjustable 5 tone transmitted Selcall Ident. Also
allows alphanumeric naming of up to 10 Idents for
easier caller identification.
•User selectable Wide/Narrow Receive Filter
•Dual Microphone Input Sockets: Front and
rear microphone sockets to match most installation
needs. Both sockets can be used independently or
simultaneously.
•Overvoltage Protection: Special overvoltage
detection circuitry protects the radio and warns of
excessive voltage conditions by flashing the display.
•Surface Mount Technology: The very latest
surface mount component types, design and assembly
techniques and quality control procedures are used to
ensure the highest performance and reliability.
• Designed and Manufactured in Australia:
Totally designed and manufactured in Gladesville to
meet the demanding needs of the
Australian community.

TX4500 INSTRUCTION MANUAL PAGE 5
REAR PANEL
FRONT PANEL CONTROLS
GENERAL OPERATIONS
Volume Control
Liquid Crystal Display
Channel Switch
Speaker
Squelch
Control
Menu/
Function
Scan/
OS-GS
Priority 1/
Priority 2
Duplex/
Alpha
Silent/
Quiet
Front Mic
Socket
SILENT
QUIET
DUP
ALPHA
VOLUME
SQUELCH
CHANNEL
PRI 1
PRI 2
SCAN
OS/GS
MENU
F
LCD PANEL
Scan
Quiet Busy Transmit
Channel Display
Selcall/Alpha Display/
Signal Meter/Battery
Repeater
(Duplex) Quiet
Tag CTCSS/DCS
Selcall RXSelcall TX
13.8V
DC
ANTENNA MIC SPK
Extension Speaker
Socket
13.8 V DC Socket
Antenna Socket Rear Mic Socket

PAGE 6 INSTRUCTION MANUAL TX4500
KEYPAD FUNCTIONS
All controls on the TX4500 front panel have multiple
functions. The primary functions are labelled in BLACK,
while the secondary functions are labelled in RED. To
access a primary function simply press the required key.
To access a secondary function, briefly press the Fkey
followed immediately by the required key.
NOTE: When using the Fkey to access other functions,
Fis displayed to indicate that ‘Function’ mode is
activated. If the required function is not selected within
5 seconds the Fkey selection will time out with a low
beep and Fwill disappear from the display.
More detailed descriptions of these key functions are
included in this ‘General Operation’ section.
VOLUME
Rotate the Volume control clockwise past the click to
turn the radio on. Rotate the Volume control left or
right to adjust the volume.
If no sound is heard, rotate the Squelch knob fully
counter clockwise to un-mute the radio then adjust the
volume while listening to the background noise. When
finished, readjust the Squelch knob to re-mute
the radio.
NOTE: At the minimum volume setting there is
still sufficient volume to be heard in a quiet cabin
environment.
SELECTING CHANNELS
To select the required channel, rotate the Channel
knob. Rotate the knob clockwise to select a higher
channel or counter clockwise to select lower channels.
The selected channel is displayed on the LCD.
SQUELCH
The Squelch is used to eliminate any annoying
background noise when there are no signals present.
The Squelch can be opened or closed using the
Squelch knob. When the Squelch is open the receiver’s
background noise can be heard and the symbol
is displayed. When the Squelch is closed the receiver
remains quiet while there are no signals present but any
incoming signals will override the Squelch and be heard
in the speaker.
Adjusting the Squelch level
The TX4500 features a continuously variable Squelch
control system allowing the user to set the Squelch for
optimum performance.
To adjust the Squelch, first rotate the Squelch knob
fully counter-clockwise until the background noise is
heard and the indicator is displayed on the LCD.
Now advance the Squelch knob slowly clockwise
until the noise is just extinguished and the indicator
disappears. At this point the receiver will remain quiet
while no signals are present but an incoming signal will
override the Squelch and be heard in the speaker. As
the Squelch knob is advanced further clockwise the
Squelch action is progressively increased and stronger
incoming signals are needed to overcome it.
Note: If an incoming signal is very weak and is close
to the minimum Squelch level it may become broken or
‘chopped’ by the Squelch action. To prevent this simply
turn the Squelch knob fully counter-clockwise to open
the Squelch. This will allow a clearer signal.
SIGNAL METER
The signal meter indicates the relative strength of the
incoming signal in numerical format. Signal strengths
are displayed on the lower right of the channel display
in values from 0 to 9. Signals above strength 9 are
displayed as 9+.
NOTE: Refer to the Configuration Menu for other
options that can be displayed in this location.
MICROPHONE
Channel
Up
Channel
Down
Push To
Talk
Priority
Skip/Call

TX4500 INSTRUCTION MANUAL PAGE 7
TRANSMITTING
Prior to transmitting, always check the channel is not
being used. This can be done by listening to the channel
or by visually checking that the icon is not visible or
the signal meter is not indicating a signal.
To transmit, press the PTT switch on the microphone.
The icon will appear. Hold the microphone about
5-8 cm from your face and speak at a normal voice
level. The microphone is quite sensitive so it is not
necessary to raise your voice or shout. Release the PTT
when you have finished talking. The icon
will disappear.
IMPORTANT: Always listen to ensure the channel is
free before transmitting.
TIME-OUT TIMER
The radio has a built-in time-out timer that
automatically limits transmissions to a maximum of 3
minutes of continuous operation. This feature is required
by the ACMA to prevent accidental blocking of the
frequency should your PTT switch become jammed or be
otherwise pressed accidentally. The time-out period can
be changed by your dealer.
When the time-out timer activates, the radio will beep
for 5 seconds then the icon will flash continuously.
Normal operation will be restored once the PTT is
released.
BACKLIGHTING
The Liquid Crystal Display and keys are backlit for easy
viewing at night. The backlight remains on while the
radio is switched on.
Adjusting the Backlighting
The backlight brightness and colour can be adjusted for
personal preference.
To make adjustments to the backlighting, press and
hold the Channel knob for several seconds. BKLGT
will be displayed indicating the Brightness setting is
selected. Briefly press the Channel knob to cycle
through the available settings. Rotate the Channel
knob left or right to adjust the current setting.
There are three backlight settings available;
BKLGT (Brightness Setting): Provides a continuously
variable brightness adjustment from very dim to
full brightness.
COLOR (Colour Setting): Provides a continuously
variable colour spectrum change via a smooth blend
of colours.
WHITE (Whiteness Setting): Controls the whiteness
or colour saturation of the selected colour from full
colour to white (no colour).
TIP: For the deepest colour range, reduce the
‘WHITE’ setting.
After making your selection, press and hold the
Channel knob to return to normal operation.
NOTE: The backlight setting function will automatically
time-out after 6 seconds if no further adjustments have
been made.
BANDWIDTH FILTER SETTINGS
To accommodate the blending of the newer
narrowband UHF CB 80 channel plan with the original
40 channel wideband system, your radio is fitted with
two user-selectable receiver bandwidth filters. While
either of these will provide superb receive audio,
selecting the wide filter will further increase the
tolerance of the receiver to 40 channel wideband radios
that might otherwise sound over-modulated or slightly
off frequency on channels 1 – 40. Selecting the narrow
receive filter will increase the selectivity of the radio to
strong interfering signals from adjacent channels.
To select the desired filter, press and hold the MENU
key to enter the menu, then press the MENU key
repeatedly until NBFLT (Narrowband Filter) or
WBFLT (Wideband Filter) is displayed. Rotate the
Channel knob to make the desired selection.
When finished, briefly press the PTT to exit from
the Menu.
Narrowband lter selected
Wideband lter selected
NOTE: The wideband receiver filter setting is only
applied to channels 1 – 40. Channels 41 – 80 always
use the narrowband filter.

PAGE 8 INSTRUCTION MANUAL TX4500
DYNAMIC VOLUME CONTROL (DVC)
The modulation level of signals heard on the UHF
CB band has always varied considerably resulting
in noticeable differences in received audio volume
between stations. Generally users have compensated
for this by adjusting the volume control for each
incoming signal. With the introduction of 80 channel
narrowband transmissions that use lower levels of
modulation, the diversity in received audio volume is
likely to increase further.
Your radio is able to automatically compensate for
these variations in received audio level by utilising a
Dynamic Volume Control. When activated, this
feature automatically compensates for variations in
received audio level resulting in a constant audio output
level to the speaker.
To activate the Dynamic Volume Control, press and
hold the MENU key to enter the menu, then press the
MENU key repeatedly until DVCOF (Dynamic Volume
Control Off) or DVCON (Dynamic Volume Control On)
is displayed. Rotate the Channel knob to make the
desired selection.
When finished, briefly press the PTT to exit from
the Menu.
Dynamic Volume Control ON
Dynamic Volume Control OFF
VOICE SCRAMBLER
Your radio incorporates a simple voice scrambler using
band inversion. The scrambler is compatible with the
majority of scramblers used by other manufacturers,
allowing you to enjoy scrambled communications with
owners of non-GME radios. Once the scrambler has
been activated your transmission and reception
will only be intelligible to others using the same
scrambler technology.
To enable or disable the voice scrambler:
1. Press and hold the Menu key until the
radio beeps.
2. Briefly press the Menu key repeatedly until
ENCOF or ENCON is displayed.
3. Rotate the Channel knob to make your selection.
Select ENCON to activate the scrambler encoder or
ENCOF to disable it.
4. Press the PTT to exit the menu.
Scrambler Encoder OFF Scrambler Encoder ON
REPEATERS AND DUPLEX MODE
Duplex operation allows the radio to transmit on a
different frequency to that which it receives. This allows
operation through repeater stations.
A repeater station consists of a linked transmitter/
receiver combination installed in a prominent location.
The repeater is designed to receive signals on a
designated channel and retransmit them on another
channel. Repeaters are usually mounted on hills or tall
buildings. The increased elevation greatly improves both
the receiving and transmitting range of the repeater
allowing it to receive and retransmit signals to radios
that would otherwise be out of range of each other.
Normally, UHF radios transmit and receive on the same
frequency – known as Simplex operation. However
to communicate through repeaters, your radio must
be able to transmit and receive on different channels
– otherwise known as Duplex operation. Your radio
is fitted with a Duplex key to allow you to operate
through repeaters.
The Duplex function can only be selected on channels
1–8 and 41–48 as these are the channels that have
been allocated for repeater use. When Duplex is
selected, your radio receives on the selected channel
(e.g. CH 1) but transmits 30 channels higher (CH
31). The repeater hears your signal on CH 31 and
retransmits it on CH 1 for others to hear.
Your radio allows you to enable or disable Duplex
mode on individual repeater channels. In this way
any repeater channels that are not being used with
repeaters in your area can be used in Simplex mode for
normal direct radio-to-radio communications.

TX4500 INSTRUCTION MANUAL PAGE 9
Channel
Selected
Receive
Channel
Transmit
Channel
1 1 31
2 2 32
3 3 33
4 4 34
5* 5* 35*
6 6 36
7 7 37
8 8 38
41 41 71
42 42 72
43 43 73
44 44 74
45 45 75
46 46 76
47 47 77
48 48 78
*Emergency channel only
To enable Duplex on a Repeater channel
1. Select the required repeater channel (1-8, 41-48).
2. Briefly press the DUP key. The duplex symbol
will appear on the display accompanied by a
high beep.
To remove Duplex from a Repeater channel
1. Select the required repeater channel (1-8, 41-48). If
duplex is currently selected, the duplex symbol
will be displayed.
2. Briefly press the DUP key. The duplex symbol
will disappear from the display accompanied by a
low beep.
IMPORTANT: Channels 1-8, 31-38, 41-48 and 71-78
should only be used in Simplex mode if there are no
repeaters in or near your location that operate on
the selected channel. In particular, avoid operating in
Simplex mode on any of the repeater input channels
31-38 and 71-78 unless you are absolutely sure that
there are no repeaters in range using that channel.
Inadvertently transmitting on an active repeater input
frequency in simplex mode could cause interference to
other users on that repeater that would not be audible
to your radio.
PRIORITY CHANNELS
The Priority Channel feature allows you to instantly
recall any of the 80 channels in your radio. This feature
can be used to provide instant access to your working
channel or your local repeater channel at the press of a
key. It can also be used in conjunction with the Group
Scan function.
Your TX4500 has provision for two separate
Priority channels.
To Store Priority Channel 1
1. Select the required channel.
2. Press and hold the PRI 1key. The channel number
will flash then a high beep will be heard as the
channel is stored. 'PRI-1' will be displayed briefly.
To Store Priority Channel 2
1. Select the required channel.
2. Press Fthen immediately press and hold the PRI 2
key. The channel number will flash then a high beep
will be heard as the channel is stored. 'PRI-2' will be
displayed briefly.
To Recall Priority Channel 1
1. Briefly press the PRI 1 key. The radio will
immediately switch to the Priority 1 channel and 'PRI-
1' will be displayed briefly.
To Recall Priority Channel 2
1. Press Fthen briefly press the PRI 2 key. The radio
will immediately switch to the Priority 2 channel and
'PRI-2' will be displayed for a few seconds.
NOTE: If the radio was scanning when either of the
Priority channels were selected, the scan will
be cancelled.
SCANNING
Your radio incorporates a Scan function that allows a
selected group of channels to be scanned for activity.
Channels are scanned at a rate of 20 channels per
second. If a signal is detected on a channel, the scan
will pause to allow the signal to be heard. Once the
channel has been clear for 5 seconds the scan
will resume.
Scan Groups
Your radio supports two Scan groups – Open Scan
and Group Scan.

PAGE 10 INSTRUCTION MANUAL TX4500
Open Scan allows a group of channels to be scanned
in an ascending sequence. If a signal is found, the scan
will pause on that channel. During this time you can
press the PTT switch on the microphone and talk on
the channel. Once the channel has been clear for 5
seconds the scan will resume.
Example: Scanning channels 1 – 8 in Open Scan
1 - 2 - 3 - 4 - 5 - 6 - 7 - 8
Group Scan allows you to transmit and receive on your
Priority channel, but during periods of inactivity, the
radio will also scan a group of other channels. Signals
received on the Priority channel will have precedence
over those received on the other channels. Similarly,
pressing the PTT while scanning will cause the radio to
revert to the Priority channel. Once the Priority channel
has been clear for 5 seconds the scan will resume.
Example: Scanning channels 1 – 8 with Priority
channel 20 in Group Scan
1 - 2 - 3 - 4 - 20 - 5 - 6 - 7 - 8 - 20
Selecting a Scan Group
To switch between Open or Group Scan modes, briefly
press Fthen press OS/GS. Open or Group will be
displayed to the right of the channel display for a
few seconds.
To add or remove channels from the Scan
memory
1. Check that the radio isn’t already scanning. If it is,
briefly press the SCAN key to cancel the scan.
2. Select the required channel.
3. Check to see if the Scan symbol is displayed on
that channel.
I. If is displayed, the selected channel is
already in the Scan memory. Press and hold the
SCAN key to remove it. will disappear.
II.If is not displayed, the selected channel
is not in the Scan memory. Press and hold the
SCAN key to add the selected channel to the
Scan memory. will now be displayed on that
channel.
Quick select
To quickly switch between channels that have been
stored in the current Scan memory, briefly press the F
key then rotate the Channel knob. This will allow you
to manually step through only those channels that have
been stored in the current Scan group memory. During
this time Fwill remain on the display to confirm you
are still in ‘Quick Select’ mode. To exit this mode, press
the Fkey again or wait 10 seconds for the function to
time out.
This option can be used to quickly jump between
channels of interest or to quickly review which channels
are in the Scan memory for editing purposes.
Scanning in Open Scan mode
Briefly press the SCAN key. A high beep will be heard
and the Scan symbol will animate. During this time the
channel numbers will scroll rapidly as the channels
are scanned.
NOTE: If there are less than 2 channels programmed
into the Scan memory when you press SCAN, a low
beep will sound and the command will be ignored.
If a busy channel is located, the scan will pause to allow
you to hear the signal but will continue to animate on
the display to indicate that the scan function is still
active. Once the channel has been clear for 5 seconds,
the scan will resume.
If you don’t wish to listen to a busy channel you
can skip over it by pressing the Skip button on the
microphone or rotating the Channel knob. Scanning
will resume at the next available channel in memory.
Default working channel in Open Scan mode
In the Open Scan mode, your default working channel is
the channel your radio switches to when you press the
PTT while scanning. To define your working channel
simply select the required channel before you press
the SCAN key. e.g. to make channel 24 your working
channel, simply select channel 24 before pressing the
SCAN key.
To talk on your working channel while scanning,
simply press the PTT. The scan will pause and your
radio will switch to your working channel allowing you
to transmit and receive on that channel. Once your
communication has finished and the channel has been
clear for 5 seconds, scanning will resume.
If your radio pauses on a busy channel (other than your
working channel) and you wish to talk on that channel,
simply press the PTT during a break in the conversation.
The busy channel now becomes your new working
channel, replacing your previous working channel. Once
your communication has finished and the channel has
been clear for 5 seconds, scanning will resume.
Scanning in Group Scan mode
Group Scan mode is slightly different to Open
Scan mode in that the Group Scan allows you to
communicate on your Priority channel while continuing

TX4500 INSTRUCTION MANUAL PAGE 11
to scan a number of other channels. The receiver will
scan the other channels ONLY WHILE THERE ARE NO
SIGNALS ON THE PRIORITY CHANNEL.
Channel
Signals being received on the Priority channel will
override any signals being received on any of the other
channels. In addition, if you press the PTT at any time
the radio will always transmit on the Priority channel.
Setting up Group Scan
1. Briefly press Fthen OS/GS to select the Group Scan
mode. ‘Group’ will be displayed briefly.
2. Program the required Scan channels into the Group
Scan memory (select the required channel then press
and hold the SCAN key so that is displayed on
that channel).
3. Program your Priority channels as described earlier
under ‘Priority Channel’ then select which of the
two Priority channels you wish to use for this Group
Scan session. Simply press the PRI 1 key for Priority
channel 1 or press F then the PRI 2 key for Priority
channel 2 prior to scanning.
4. Now press the SCAN key. A high beep will be heard
and the Scan symbol will animate. During this
time the channel numbers will change rapidly as
the selected channels are scanned with the Priority
channel being scanned every fourth channel.
If a signal appears on the Priority channel – at any time
– the radio will switch directly to the Priority channel
and 3 short beeps will be heard. The radio will now
stay on the Priority channel for as long as the channel
remains busy. During this time you can transmit and
receive on the Priority channel in the usual way. Once
the Priority channel has been clear for 5 seconds the
radio will resume scanning the other channels.
If a signal appears on one of the other channels,
scanning will pause on that channel and will remain
there while the channel is busy – as long as there are
no signals on the Priority channel. During this time,
the receiver will continue to check the Priority channel
every 2 seconds resulting in a series of small breaks in
the reception of the busy channel. Once the signal has
gone and there has been no activity on any channel for
5 seconds, the radio will resume scanning.
To transmit on the Priority channel at any time,
simply press the PTT. The radio will switch straight
to the Priority channel. When you have finished your
conversation and there has been no further activity for
5 seconds, the radio will resume scanning the
other channels.
If the scan pauses on a busy channel and you don’t
wish to listen to that conversation, press the Skip key
or rotate the Channel knob. The radio will skip that
channel and resume scanning.
If the radio is paused on a busy channel and you want
to remain there, briefly press the SCAN key. The radio
will exit Scan and remain on the busy channel. At this
point you will no longer be monitoring the
Priority channel.
To resume scanning press the SCAN key again.
To exit the Scan mode and go directly to the Priority
channel at any time, press PRI 1 for Priority channel 1
or Fthen PRI 2 for Priority channel 2.
Scan Group options
By default your radio has one Open Scan mode and one
Group Scan mode. There may be applications where
you have no need to monitor a Priority channel and
would prefer to have two separate Open Scan modes.
Alternately you may prefer to have two separate Group
Scan modes with different Scan channels in each. Your
radio can be programmed to convert the Group Scan
into an Open Scan and vice versa. If this is required,
please contact your GME retailer to arrange for this
feature to be activated.
When two Open Scan or two Group Scan modes are
enabled, the Scan Group selection screen will display
Open1 and Open2 for the Open Scan groups or GRP1
and GRP2 for the Group Scan groups. See the section
‘Selecting a Scan Group’.
NOTE: Enabling or disabling the second Open or
Group Scan mode is not a user selectable option. Once
enabled or disabled, the new Scan mode becomes a
permanent part of your radio’s features. If you decide
later that you need the original Scan mode settings
restored you will need to return your radio to your GME
retailer for re-programming.
CTCSS & DCS
The standard Squelch system is fine for quietening 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 which can make it difficult to determine which
calls are meant for you. CTCSS/DCS provides additional
selective receiver audio muting using sub-audio
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
who use the same subtone as you.

PAGE 12 INSTRUCTION MANUAL TX4500
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
There are two CTCSS tone sets available – the basic 38
tone set or the extended 50 tone set (see the CTCSS
tone chart at the rear of this manual). Both are included
to ensure compatibility with other radios.
To switch between CTCSS tone sets;
1. Switch the radio OFF.
2. Press and hold the Silent key while switching the
radio ON again.
3. CTC38 or CTC50 will appear briefly.
NOTE: When switching between tone sets, if you
already have a CTCSS tone selected, the radio will try to
match the original tone frequency with one in the new
table. If there is no tone match, the CTCSS tone will be
set to OFF and you will need to select a new tone.
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. Select any UHF CB channel 1 – 80
(excluding 5 and 35).
2. Press and hold the Menu key until the radio beeps.
The CTCSS Menu option will be displayed.
3. If CTCOF is displayed, CTCSS/DCS tones are
currently switched off (default). To enable CTCSS
tones, rotate the Channel knob to the right. CTCSS
tones will be displayed as CTC01 – CTC50.
4.
Continue rotating the Channel knob to scroll past
the last CTCSS tone (38 or 50) to access the DCS
tones. DCS tones are displayed as DT001 – DT104.
Rotate left
CTCSS Off CTCSS Tone 50 DCS Tone 104
Rotate right
5. To see the actual sub tone instead of the tone label,
briefly press the Channel knob. For CTCSS tones the
tone frequency will be displayed in Hz. For DCS tones
the Tone Code will be displayed. Press the Channel
knob again to return to the CTCSS/DCS label (refer
to the CTCSS and DCS Tone Charts on pages 31–32.
CTCSS Label CTCSS Sub tone
Frequency
6. To switch CTCSS/DCS tones Off, rotate the Channel
knob fully to the left until CTCOF is displayed.
To exit the menu, briefly press the PTT or wait for the
menu to time-out.
NOTE: The selected CTCSS/DCS tone will be used
globally on any channels that have CTCSS enabled.
Enabling CTCSS/DCS on a channel (Silent Mode)
Enabling CTCSS/DCS on a channel will prevent the
Squelch from opening unless the incoming signal
matches your selected CTCSS/DCS tone. Other users on
the same channel who are not using your CTCSS/DCS
tone will still be received by your radio (the icon will
still appear on the display) – but their voice will not be
heard in the speaker. Only when someone transmits
on the channel using your CTCSS/DCS tone will the
Squelch open to allow the signal to be heard. Channels
where CTCSS/DCS have been enabled are said to be in
‘Silent Mode’.
NOTE: Silent Mode can be enabled on any channel
except emergency channels 5 and 35.
To enable Silent Mode on a channel:
1. Select the required channel.
2. Briefly press the Silent key. A high beep will be
heard and an icon (CTCSS) or icon (DCS)
will be displayed in the lower right of the display to
indicate Silent Mode is now enabled on
that channel.
NOTE: You cannot enable Silent Mode unless a CTCSS
or DCS tone has been selected in the Configuration
Menu. If CTCSS/DCS has been set to OFF, Silent Mode
is inhibited.
To disable Silent Mode on a channel:
1. Select the required channel. An icon (CTCSS) or
icon (DCS) will be displayed indicating Silent

TX4500 INSTRUCTION MANUAL PAGE 13
Mode is enabled.
2. Briefly press and hold the Silent key. A low beep
will be heard and the (CTCSS) or (DCS) icon
will disappear to indicate Silent Mode has been
removed from that channel.
IMPORTANT: When Silent Mode is enabled on a
channel you should always check the icon for signs
of traffic on the channel before transmitting to ensure
you do not accidentally transmit over the top of another
user. Alternatively, you can enable Busy Lockout in
the Configuration Menu which will automatically
prevent your radio from transmitting if the channel is
already in use.
Monitor function
When the current channel is in Silent Mode, the icon
may appear but no sound will be heard in the speaker.
This indicates that your radio is receiving a signal that
does not match your CTCSS/DCS tone. If you wish, you
can briefly monitor the channel as described below. This
temporarily disables Silent Mode, allowing the signal
to be heard.
To monitor signals on the channel, press and hold the
Squelch knob. When you release the Squelch knob,
Silent Mode is restored and the radio will become
quiet again.
SELECTIVE CALLING
Overview
Your radio has a Selective Calling system known as
Selcall that operates like a telephone. Your radio is pre-
programmed with its own unique Selcall Identification
number. If this number is called by another radio, your
radio will beep to alert you. If you do not want to hear
any other activity while waiting on a channel, you can
select the Quiet Mode. Your radio will then remain
quiet to all incoming signals until your Selcall number
is called.
Your radio will allow you to store up to ten of your most
frequently called Selcall numbers in memory and each
number can be labelled for easy identification.
Selcall identification number
Your radio is factory programmed with its own unique
Selcall Identification Number (Ident). This number
identifies your radio from others in your area. Your
radio’s own Selcall Ident will be displayed for a few
seconds to the left of the channel display when you
first turn the radio on. You will need to make your
Ident known to anyone who may need to call you
using Selcall.
NOTE: Although your radio is factory-programmed with
a unique Selcall Ident, you can change your Ident to
another number if required (see Selcall Memories on
next page).
Selcall Ident labels
When storing Selcall Idents, you can add labels to each
one to make it easier to identify whose Ident you are
recalling. In addition, if an incoming Selcall matches
one of your stored Idents, the label can be displayed
instead of the Ident.
To add or display labels, your radio must be in the
ALPHA mode. To switch between ALPHA mode and
NUMERIC mode, briefly press the Fkey followed by the
ALPHA key. ‘ALPHA’ or ‘NUMBER’ will be displayed
briefly to the left of the channel display to indicate the
selected mode.
The Quiet Mode
Your radio can be set to monitor signals on a busy
channel but remain QUIET unless it receives its own
Selcall Ident. In this way, you won’t be disturbed unless
someone calls you. When your Selcall Ident is received,
the Quiet Mode is deactivated and an alarm sounds to
alert you to the call. You can then converse normally on
the channel. To use the Quiet Mode, refer to the Quiet
Mode section further below.
NOTE: The Quiet Mode overrides the normal Squelch
system to ensure that the radio remains quiet even
when the channel is busy. When QUIET is set, you
may see the icon appear on the display indicating
the channel is being used. However, unless someone
transmits your Selcall Ident, nothing will be heard in
the speaker.
You can activate the Quiet Mode on individual channels
i.e. some channels can be set to remain Quiet while
others can remain open to all incoming signals.
USING SELCALL
Entering a Selcall Ident
1. Press the CALL button. is displayed, along
with the last sent or received Selcall Ident. If an
ALPHA label is displayed you will need to press F
then ALPHA to switch to Numeric mode.
2. Press and hold the Channel knob until the radio
beeps. The right-hand digit of the Selcall Ident
will flash.
3. Rotate the Channel knob to select the required
number in the flashing digit position.
4. Briefly press the Channel knob again to select the
next digit position.

PAGE 14 INSTRUCTION MANUAL TX4500
5. Repeat steps 4 and 5 to enter all 5 digits as required.
The Selcall number is now ready to send.
6. Press and hold the CALL button. A long beep will be
heard and the radio will transmit the Selcall Ident.
NOTE: If the call is not sent within 10 seconds of
entering the last Ident digit the Call function will time-
out and the radio will return to normal mode. To exit
the mode without sending the Selcall, briefly press
the CALL button.
Call acknowledge
If your Selcall transmission is successful, the radio you
called should respond with an ‘acknowledge’ signal -
usually two quick beeps. This will confirm to you that
the radio you called is now alerting its user to
your signal.
Selcall memories
Your radio is fitted with one ‘Call’ memory and 10 user
programmable Selcall memories labelled ‘C0’ to ‘C9’
There is also one additional location labelled ‘Id’.
Memory locations ‘C0’ to ‘C9’ are for storing frequently
called Selcall Idents. The additional location labelled ‘Id’
contains your radio’s own Selcall Ident. You should only
select this memory location if you need to change your
radio’s factory programmed Selcall Ident.
To store a Selcall Ident in memory
1. Briefly press the CALL button. is displayed along
with the last sent or received Selcall Ident.
2. Rotate the Channel knob clockwise to select the
required Ident memory location ‘C0’ to ‘C9’ (or
select ‘Id’ to change your radios own Selcall Ident). If
an ALPHA label is displayed you will need to press F
then ALPHA to switch to Numeric mode.
3. Press and hold the Channel knob until the radio
beeps. The right-hand digit of the Selcall Ident
will flash.
4. Rotate the Channel knob to select the required
number in the flashing digit position.
5. Briefly press the Channel knob again to select the
next digit position.
6. Repeat steps 4 and 5 to enter all 5 digits as required.
7. Now press and hold the Channel knob. The entire
Ident will flash for a few seconds then the radio will
beep as the new Ident is stored.
e.g. Programming Call Memory C5
Recalling Selcall Idents
1. Briefly press the CALL button. is displayed along
with the last sent or received Selcall Ident.
2. Rotate the Channel knob to select the required
Ident memory in locations ‘C0’ to ‘C9’.
3. Press and hold the CALL button to send the Ident.
Naming your Selcall Idents
Your radio allows you to label each Selcall Ident using
a 5 character name to make it easier to identify callers.
If an incoming Selcall matches one of those in your
radio’s memory, the label can be displayed instead of
the Selcall Ident.
NOTE: Before adding an ALPHA label to a Selcall Ident,
you must first store the required Ident in memory as
described left.
1. Briefly press the CALL button. will be displayed
along with the last sent or received Selcall Ident.
2. Rotate the Channel knob to select the required
Ident memory in locations ‘C0’ to ‘C9’.
3. Briefly press the Fthen ALPHA to select the ALPHA
mode. ALPHA will be displayed briefly.
4. If the ALPHA label is empty, ‘- - - - -’ will be
displayed, otherwise it will display the last ALPHA
label programmed into that memory.
5. Press and hold the Channel knob until the radio
beeps. The left-hand position of the Alpha label will
flash.
6. Rotate the Channel knob to select the required
character in the flashing position then briefly press
the Channel knob again to select the next position.
7. Repeat step 6 to enter up to 5 characters
as required.
8. Now press and hold the Channel knob. The entire
Alpha label will flash for a few seconds then the
radio will beep as the label is stored.

TX4500 INSTRUCTION MANUAL PAGE 15
e.g. Programming Call Memory C5
Recalling Selcall Idents
1. Briefly press the CALL button. is displayed along
with the last sent or received Selcall Ident.
2. Rotate the Channel knob to select the required
Ident memory in locations ‘C0’ to ‘C9’.
3. Press and hold the CALL button to send the Ident.
Naming your Selcall Idents
Your radio allows you to label each Selcall Ident using
a 5 character name to make it easier to identify callers.
If an incoming Selcall matches one of those in your
radio’s memory, the label can be displayed instead of
the Selcall Ident.
NOTE: Before adding an ALPHA label to a Selcall Ident,
you must first store the required Ident in memory as
described left.
1. Briefly press the CALL button. will be displayed
along with the last sent or received Selcall Ident.
2. Rotate the Channel knob to select the required
Ident memory in locations ‘C0’ to ‘C9’.
3. Briefly press the Fthen ALPHA to select the ALPHA
mode. ALPHA will be displayed briefly.
4. If the ALPHA label is empty, ‘- - - - -’ will be
displayed, otherwise it will display the last ALPHA
label programmed into that memory.
5. Press and hold the Channel knob until the radio
beeps. The left-hand position of the Alpha label will
flash.
6. Rotate the Channel knob to select the required
character in the flashing position then briefly press
the Channel knob again to select the next position.
7. Repeat step 6 to enter up to 5 characters
as required.
8. Now press and hold the Channel knob. The entire
Alpha label will flash for a few seconds then the
radio will beep as the label is stored.
e.g. Labelling Call memory C5
Repeat steps 2 to 8 to add ALPHA labels to any
other Selcall Idents stored in memory. The following
characters are available;
Letters A B C D E F G H I J K L M N O
P Q R S T U V W X Y Z
Numbers 0 1 2 3 4 5 6 7 8 9
Punctuation <space> * +
To exit the CALL TO mode, briefly press the CALL
button (or simply wait for the Call function to time out).
The radio will return to normal operation.
To display the Alpha labels of incoming Selcalls,
the radio should be left in Alpha mode. Any incoming
Selcall that does not match those in the memory will
display -NEW-. To display the Selcall Ident of that caller,
briefly press Fthen ALPHA to return to the
NUMERIC mode.
Receiving Selcalls
When your radio receives it’s Selcall Ident, an alarm will
sound to alert you to the call. Initially the alarm will
beep urgently at 2 beeps per second, then, if the call
is not answered, it will slow to around 1 beep every 3
seconds. It will then continue to beep indefinitely until
you cancel it.
In addition to the alarm, the symbol will appear on
the display along with the callers Selcall Ident or ALPHA
label to inform you of the caller’s identity.
Incoming call showing Selcall Ident
Incoming call showing Alpha label
To return the call:
Press and hold the CALL button for a few seconds until
the radio beeps. The caller’s Selcall will be sent back to
the caller.
To cancel the alarm:
Briefly press the PTT switch. The alarm will be
cancelled and the channel will be open for normal
communication. You can now talk on the channel in the
usual way.
QUIET MODE
The Quiet Mode mutes the receiver to prevent incoming
signals from being heard in the speaker until your
Selcall Ident is received. In this way you can monitor a
busy channel for personal calls without being disturbed
by unwanted signals. If your Selcall Ident is received,
the Quiet Mode is cancelled and all incoming signals
are heard in the speaker.
Setting up the Quiet Mode
To setup the Quiet Mode you must first ‘tag’ the
channels that you want to stay Quiet, then activate the
Quiet Mode. Once the Quiet Mode is activated, tagged
channels will remain Quiet to all incoming signals
unless your Selcall Ident is received. Channels not
tagged will remain open to all signals and will operate
normally.
To tag individual channels for QUIET operation:
1. Select the required channel.
2. Briefly press Fthen press and hold QUIET until the
radio beeps. ‘Q’ will appear on the lower right of
the display channel number indicating the selected
channel is now tagged for Quiet operation.
To remove the QUIET tag from individual
channels:
1. Select a channel that has been tagged for Quiet
operation. ‘Q’ will be displayed.
2. Briefly press Fthen hold QUIET until the radio
beeps. ‘Q’ will disappear indicating this channel is no
longer tagged for Quiet operation.
Activating the Quiet Mode
1. Select a channel that has been tagged for Quiet
operation (you cannot activate the Quiet Mode
unless you have selected a ‘tagged’ channel). ‘Q’ will
be displayed.
2. Briefly press Fthen press QUIET. will appear on
the display.
Now all channels that were tagged for Quiet operation
will be operating in the Quiet Mode.

PAGE 16 INSTRUCTION MANUAL TX4500
De-activating the Quiet Mode
1. Select any channel that has been tagged for Quiet
operation. ‘Q’ and will be displayed.
2. Briefly press Fthen press QUIET. will disappear
from the display and all channels that were tagged
for Quiet operation will now operate normally again.
Receiving signals in the Quiet Mode
•If a normal signal is received on a QUIET channel, the
channel will appear busy (the icon will be visible)
but no sound will be heard from the speaker.
•If a normal signal is received on an Open channel
(one that is not tagged with ‘Q’) the signal will be
heard in the usual way.
•If your Selcall Ident is received on any channel - Open
or QUIET - the Quiet Mode will be cancelled and the
alarm will beep to alert you to the call. In addition,
the caller’s Ident or ALPHA label will be displayed. All
channels will now be open for normal transmission
and reception.
If you wish to respond to the caller using Selcall, press
and hold the CALL button until the radio beeps. The
caller’s Ident will be transmitted back to them causing
the alarm in their radio to be activated.
To cancel the alarm on your radio, briefly press
the PTT.
To return your radio to the Quiet Mode, briefly
press Fthen press QUIET. will re-appear on
the display.
Scanning in the Quiet Mode
The radio will allow you to scan while the Quiet Mode
is active. Using this feature you can monitor a group of
Quiet channels or a combination of Quiet and
Open channels.
To Scan in the Quiet Mode:
1. Pre-select the required OS or GS Scan group (briefly
press Fthen OS/GS).
2. Program your Scan channels as described under the
Scanning section.
3. From those channels, select the ones you wish to
remain Quiet and tag each one for QUIET operation
(press Fthen press and hold QUIET).
4. Select a tagged channel and activate the Quiet Mode
(briefly press Fthe press QUIET).
5. Press the SCAN key. The radio will begin scanning
and ‘SCAN’ and will be displayed, indicating the
radio is scanning in the Quiet Mode.
Receiving signals while scanning in the
Quiet Mode
•If a normal signal is received on an open channel,
scanning will pause while the channel is busy and
will resume scanning 5 seconds after the channel
becomes clear. (If you were scanning in Group Scan
mode, the radio may switch between the open
channel and the Priority channel - this is normal).
•If a normal signal is received on a Quiet channel but
your Selcall Ident is not detected, the signal will be
ignored and scanning will continue.
•If a signal containing your Selcall Ident is received
on any channel - Open or Quiet - both scanning and
Quiet Modes will be cancelled and the receiver will
stay on that channel. In addition, the alarm will beep
to alert you to the call and the callers Ident or ALPHA
label will be displayed. The channel will now be open
for normal transmission and reception.
TIP: To ensure reliable Selcall detection when scanning
in the Quiet Mode, it is recommended that you restrict
the number of channels in the Scan group to 4 or less.
GROUP CALLING
The Selcall system includes a Group Call function which
allows you to call up to 1000 radios simultaneously.
This can be useful in an emergency situation where you
may need to transmit a message to a large number of
radios in your group.
By default, your radio is factory-set to allow up to 10
radios to be called at once. If your application requires
more, you can arrange for your Dealer to re-program
this option to allow 100 or 1000 radios to be called.
The following description assumes the default Group
Call setting of 10 radios.
The Group Call function works by allowing you to enter
a special ‘group code’ into the last digit positions of the
Selcall Ident you are sending. The ‘group code’ appears
as an ‘A’ when displayed in the radio. When this ‘group
code’ is received, it substitutes for all other numbers in
that position. As long as the first 4 digits of the Selcall
you are sending match those of the radios you are
calling, their Selcall alarm will be activated as if their
full 5 digit Selcall Idents had been received.
To achieve this, the 10 radios you are calling must be
programmed with sequentially numbered Selcall Idents.
e.g. 14530, 14531, 14532, 14533 . . --> , 14539
•Transmitting the Selcall Ident 14531 will only activate
the alarm in the radio with the Selcall Ident of 14531.

TX4500 INSTRUCTION MANUAL PAGE 17
•Transmitting 1453A will activate the alarms in all
radios with Idents 14530 through 14539 (a total of
10 radios).
If the radios in your fleet do not have sequentially
numbered Selcall Idents and you want to make use of
this function, you will need to re-program the Selcall
Idents in your radios.
Programming and sending Group calls
The process for entering a Group call Ident is the same
as entering a normal Selcall Ident.
1. Press the CALL button. is displayed, along with
the last sent or received Selcall Ident. If an ALPHA
label is displayed you will need to press Fthen
ALPHA to switch to Numeric Mode.
2. Press and hold the Channel knob until the radio
beeps. The right-hand digit of the Selcall Ident will
flash.
3. Rotate the Channel knob to select ‘A’ in the
flashing digit position. This is the special code that
will create the Group Call.
4. Briefly press the Channel knob again to select the
next digit position.
5. Continue entering the other 4 digits as required. The
Selcall number is now ready to send.
6. Press and hold the CALL button. A long beep will be
heard and the radio will transmit the Selcall Ident.
NOTE: Where your radio allows it, programming group
calls for 100 radios is identical except that you will need
to select ‘A’ for the last two digits (e.g. 123AA). For
1000 radios you will need to select ‘A’ for last three
digits (e.g. 12AAA).
e.g.
Sending Ident 145AA will call 100 radios with Idents
14500 -> 14599
Sending Ident 14AAA will call 1000 radios with Idents
14000 -> 14999
You can also arrange to send Selcalls to every tenth
radio by setting the second digit to A.
e.g.
Sending Ident 145A5 will call radios 14505, 14515,
14525, 14535, 14545 . . -> 14595
Call acknowledge in Group mode:
There is no call acknowledge when sending group
calls. This is to prevent all the radios in your group from
trying to respond to your Selcall transmission at the
same time.
Storing Group call Idents:
Group call Idents can be stored in memory in the same
way as a standard Selcall Ident.
Receiving Group calls:
Receiving a Group call is identical to receiving a normal
Selcall except that the alarm sound is a LOW tone beep
instead of the normal High tone beep. The caller’s Ident
or ALPHA label appears on the display in the usual way.
RECEIVE (RX) ONLY CHANNELS
The radio includes support for up to 95 user
programmable RX-Only channels with frequencies in the
range 403 – 520 MHz. Frequencies can be stored in five
separate channel banks labelled Ato E, each containing
up to 19 channels. In addition, each RX-Only channel
can be assigned an individually programmable Alpha
label to help identify that channel when it is selected.
Frequency and channel bank selections are accessed
through the configuration menu.
Selecting Channel Banks
Before programming or recalling channels you should
ensure you have selected the required channel bank.
The 5 channel banks can be accessed through the
Configuration menu. The default channel bank is
labelled RX-A.
RX-ONLY CHANNEL BANK
Bank Channels
A 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99
B 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99
C 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99
D 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99
E 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99

PAGE 18 INSTRUCTION MANUAL TX4500
To select a Channel Bank
1. Press and hold the Menu key. A high beep will be
heard and the radio will enter the configuration
menu.
2. Briefly press the Menu key repeatedly until the RX-
channel bank option is displayed.
3. Rotate the Channel knob to select from one of five
channel banks RX-A through RX-E.
4. When finished, press the PTT to exit the menu.
Programming RX-Only channel frequencies
RX-Only channels are switched off by default. To
program RX-Only channels you will need to activate the
channel editor which will then allow access to channels
81-99 in the currently selected channel bank. RX-Only
channels can be programmed with frequencies in the
range 403 – 520 MHz.
To program RX-Only frequencies, your radio must be
in Numeric mode. If your radio is in Alpha mode briefly
press F - ALPHA so that ‘NUMER’ is displayed.
To activate the Channel Editor
1. Switch the radio off.
2. Press and hold the Channel knob while switching
the radio on again.
3. RXALL will be displayed briefly, indicating the RX
Channel Editor has been activated.
You can now rotate the Channel knob past channel
80 to select additional channels 81-99. –OFF- will be
displayed to the right of the channel numbers indicating
that these channels are switched off and do not yet
contain any frequencies.
Selecting Frequency Steps
NOTE: This menu option is only available when RX-
Only channels are selected.
The frequency step is the spacing between frequencies
when the Channel knob is rotated. The frequency
step can be set to either 12.5 kHz or 25 kHz. The
default is 25 kHz. You should select a frequency step
that matches the channel allocations in the frequency
band you are programming. When selecting 25 kHz or
12.5 kHz steps, the appropriate wideband or narrow
band filter is automatically selected to ensure optimum
performance.
1. Press and hold MENU until the radio beeps.
2. Briefly press MENU repeatedly until the frequency
step is displayed.
25 kHz Steps 12.5 kHz Steps
3. Rotate the Channel knob left or right to change the
frequency step.
4. Press the PTT to exit the menu.
To program an RX-Only frequency:
1. Rotate the Channel knob to select a suitable
channel number (81-99). –OFF- will be displayed to
the right of the channel number.
2. Press and hold the menu key until the radio beeps.
‘–OFF-’ will flash. You now have 6 seconds to begin
programming otherwise the menu will time-out.
3. Rotate the Channel knob to the right to begin
selecting your desired frequency starting at 403
MHz. Continue to rotate to the right to increase the
frequency or to the left to decrease the frequency.
The display will show the frequency to the nearest
10 kHz.
e.g. 468.425 will display as:
4 6 8 4 2
10 kHz
100 kHz
1 MHz
10 MHz
100 MHz
5not shown
4. To advance through the frequencies more quickly,
briefly press the Channel knob. The frequency will
now adjust in 1 MHz steps. As you approach the
desired frequency, briefly press the Channel knob
again to return the original 25 kHz/12.5 kHz steps.
5. Once your desired frequency is displayed, press and
hold the Channel knob until the radio beeps. The
frequency is now stored under your selected channel
number.
e.g. 458.325 MHz stored under CH 90
6. Repeat steps 1 – 5 to program other channels.
NOTE: The frequency tuning is live which means the
radio is actually listening to the frequencies you are

TX4500 INSTRUCTION MANUAL PAGE 19
selecting. You can use this feature to locate and store
active frequencies while you are tuning.
To program more than 19 channels, you will need
to switch to another channel bank. Simply press the
MENU key repeatedly until the RX- Channel Bank
option appears then select another Channel Bank. Once
selected, press the MENU key repeatedly to return
to the frequency programming option and continue
programming your preferred frequencies.
To close the Channel Editor
Switch the radio OFF then ON again to close the
channel editor and restore normal operation. Your
programmed frequencies will now be accessible from
the Channel knob above CH80. Remember, if you
have stored channels into different channel banks, you
will need to select the appropriate channel bank to
access them.
NOTE: Under normal operation, only those channels
that have been programmed with frequencies will be
visible. Channels that were marked with –OFF- in the
channel editor will no longer be visible.
Deleting an RX-Only channel
To delete an RX-Only channel;
1. Enable the Channel Editor.
2. Select the channel you wish to delete.
3. Press and hold the MENU key until the radio beeps.
4. Rotate the Channel knob all the way to the left
until –OFF– is displayed.
5. Press and hold the Channel knob to store the new
setting.
6. Switch the radio OFF then ON again to restore
normal operation.
The deleted channel will no longer be visible.
Displaying the RX-Only channel’s frequency or
Alpha label
By default the radio displays the Signal Strength meter
to the right of the channel number. You can configure
the display to show the Frequency or the Alpha name of
the selected channel.
Before starting, ensure the radio is in the Numeric mode
(press Fthen ALPHA so that ‘NUMER’ is displayed).
1. Select an RX-Only channel (the following menu
option is only available when an RX-Only channel
is selected).
2. Press and hold MENU until the radio beeps.
3. Briefly press MENU repeatedly until S-MET appears.
4. Rotate the Channel knob to the right until ALPHA
is displayed.
5. Press the PTT to exit the Menu.
The radio will now display the channel frequency to
the right of the channel number whenever an RX-Only
channel is selected.
To display the channel’s ALPHA label
Briefly press Fthen ALPHA. ‘ALPHA’ will appear
briefly then the channel’s Alpha label will be displayed
to the left of the channel number. If the Alpha label is
blank, then an Alpha label has not yet been set for this
channel. Use the following steps to enter your preferred
Alpha label.
Adding names to your RX-Only channels
NOTE: You do not need to activate the channel editor
to make changes to RX-Only channels that have already
been programmed.
1. Select an RX-Only channel. The channel frequency
will be displayed to the left of the channel number.
2. Press Fthen ALPHA to switch to Alpha mode.
‘ALPHA’ will be displayed briefly.
3. Press and hold the MENU key until the radio beeps.
The cursor will flash in the left character position.
4. Rotate the Channel knob to select the required character.
Press the Channel knob to advance to the next character
position.
5. When the desired name is displayed, press and hold
the Channel knob to store the name.
6.
Briefly press the PTT to exit and return to
normal operation.
RX-Only channel frequency (458.325 MHz)
RX-Only channel label (CAR-4)

PAGE 20 INSTRUCTION MANUAL TX4500
When viewing RX-Only channels, briefly press Fthen
ALPHA at any time to toggle between the channel
frequency and the Alpha name.
CONFIGURATION MENU
The configuration menu controls preset functions in
the radio.
To access the menu, press and hold the MENU key
until a beep is heard. Selected menu options are
displayed to the right of the channel display. Briefly
press the Menu key to step through the available
menu options. Rotate the Channel knob to change the
selected menu option. After viewing or making changes,
briefly press the PTT to exit the menu (or simply wait a
few seconds for the menu function to time-out).
The following settings are available.
Frequency/Alpha label
(only available on receive-only channels)
Allows editing of the channel frequency or Alpha label
of the selected receive-only channel.
Frequency 458.325 MHz Alpha label “FIRE 1”
CTCSS/DCS tone selection
Enables and selects CTCSS or DCS tones. To switch
CTCSS or DCS tones OFF rotate the Channel knob fully
to the left until ‘CTCOF’ is displayed.
Voice Scrambler
Enables or disables the Voice Scrambler.
Scrambler Encoder ON
Scrambler Encoder OFF
Beep tone level
Adjusts the volume level of the beep tones associated
with key presses.
Beep level 9Beep level 0
Frequency step selection
(only available on receive-only channels)
Sets the frequency spacing of receive-only channels to
12.5 kHz or 25 kHz (default).
12.5 kHz steps25 kHz steps
Note: This option does not affect the standard 80 CB
channel spacing.
Filter bandwidth
(only available on CB channels)
Selects the receiver bandwidth filter on channels 1-40.
Narrowband Filter selectedWideband Filter selected
Dynamic Volume Control (DVC)
When enabled, automatically compensates for
variations in received audio level to provide a constant
audio output level to the speaker.
Menu Option UHF CB
Ch
RX-Only Ch
RX Only Frequency
/Alpha Label:
NA Frequency, Alpha
Label
CTCSS/DCS:CTCOF, CTC01-CTC50, DT001-
DT104
Voice Scrambler: ENCOF, ENCON
Beep Tone Level: BEEP 0 – BEEP 9
RX Only Freq.
Step :
NA 25.0 K, 12.5 K
Filter Bandwidth:WBFLT, NBFLT –
Dynamic Volume
Control:
DVCOF, DVCON
Display Mode
Options:
S-MET, S-LIN,
BATT
S-MET, S-LIN,
BATT, ALPHA
Busy Lockout: BLKOF, BLKON
RX Only Channel
Banks:
NA RX-A, RX-B, RXC,
RX-D, RX-E
CTCSS Off CTCSS Tone 50 DCS Tone 104
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