GME TX2720 User manual

TX2720 INSTRUCTION MANUAL PAGE 1
INSTRUCTION MANUAL
DIN size 4 watt 27 MHz AM CB radio
with rugged professional mic

PAGE 2 INSTRUCTION MANUAL TX2720
INTRODUCTION
The GME TX2720 is a 27 MHz AM Citizens
Band radio. The TX2720 has a number
of enhanced features including fully user
programmable Channel Scanning, Priority
Channel and backlit Liquid Crystal Display with
dimming function.
Please read this manual thoroughly to ensure
you get the best from the TX2720’s features.
For users in New Zealand, South Africa or PNG.
Please refer to amendment for local frequencies,
channel allocations and licensing requirements.
CONTENTS
SAFETY INFORMATION ................. 2
FEATURES........................... 3
ACCESSORIES SUPPLIED ................ 3
OPTIONAL ACCESSORIES................ 3
CONTROLS .......................... 3
Front panel ....................... 3
Rear panel........................ 3
Microphone....................... 4
Display .......................... 4
OPERATION - GENERAL FUNCTIONS ....... 5
Volume On/Off .................... 5
Squelch control .................... 5
Channel sSelection ................. 5
Display brightness .................. 5
Transmitting ...................... 5
Noise limiter ...................... 5
Scanning ......................... 5
Priority channel .................... 6
Dual watch ....................... 6
27 MHz CB CHANNEL ASSIGNMENTS . . . . . . 7
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . 8
Installing the DIN mount . . . . . . . . . . . . . 8
DC power connections. . . . . . . . . . . . . . . 8
Microphone. . . . . . . . . . . . . . . . . . . . . . . 9
Antenna installation . . . . . . . . . . . . . . . . 9
Noise suppression . . . . . . . . . . . . . . . . . 10
SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . 10
SC CONTRACT WARRANTY
AGAINST DEFECTS . . . . . . . . . . . . . . . . . . . . . 11
The TX2720 is a radio transmitting device.
• When transmitting, keep the antenna more than 25 mm from any part of the head or body.
• Do not transmit near electrical blasting equipment or in explosive atmospheres.
• Do not allow children to operate a radio transmitter unsupervised.
SAFETY INFORMATION

TX2720 INSTRUCTION MANUAL PAGE 3
FEATURES
•LCD display with lamp dimming function
•Rotary squelch control
•Channel scanning with memory
•Advanced noise Limiter (NL) circuitry
•Surface mount technology
•Priority channel
ACCESSORIES SUPPLIED
•TX2720 Radio unit •Microphone clip
•Din mounting kit •DC lead
•Instruction manual •Screw pack
•Microphone (MC553B)
If any items are missing or damaged, please
contact your retailer or place of purchase.
OPTIONAL ACCESSORIES
•MB42 mounting bracket
•CA30 gimbal knobs
•LEM6P 4 m microphone extension lead
CONTROLS
FRONT PANEL
VOLUME
SQUELCH
CHANNEL
Microphone
Socket
Channel Selector
Speaker LCD Display Volume
Squelch Priority Dual Watch Scan / Scan
Memory
Noise
Limiter
Dim
Antenna Socket DC Lead
External Speaker Socket Rear Mic Socket
REAR PANEL

PAGE 4 INSTRUCTION MANUAL TX2720
MICROPHONE
DISPLAY FUNCTION
Channel Number
Transmit Indicator
Busy Indicator
RX Signal Strength
Scan
D/W
Dual Watch
PRI
Priority Channel
Scan Memory
N/L
Noise Limiter
Channel Up
Channel Down
Push To Talk (PTT)
Priority
Scan
DISPLAY

TX2720 INSTRUCTION MANUAL PAGE 5
OPERATION – GENERAL FUNCTIONS
VOLUME ON/OFF
Rotate the volume control clockwise past
the ‘click’ to turn the TX2720 ON. Continue to
advance the control clockwise to increase the
volume. Rotate the control counter-clockwise to
turn the radio OFF.
SQUELCH CONTROL
The Squelch control is used to eliminate the
background noise when there are no signals
present. To adjust the Squelch, first rotate it
fully counter-clockwise until the background
noise is heard, then slowly rotate it clockwise
until the noise just disappears. If there are
signals on the channel, you should wait until
the channel is clear before adjusting the
Squelch (or select a quiet channel).
Once adjusted, the receiver will remain quiet
as long as there are no signals present, but
an incoming signal will override the Squelch
and be heard in the speaker. As the control
is advanced further clockwise the Squelch
threshold is progressively increased and
stronger incoming signals are needed to
override it. To receive very weak signals or to
disable the Squelch, simply turn the control
fully counter-clockwise.
CHANNEL SELECTION
Select the required channel using the rotary
the channel switch or by briefly pressing the
or keys on the microphone. The selected
channel is displayed on the LCD.
DISPLAY BRIGHTNESS
The LCD has two brightness levels to provide
suitable lighting for day or night use. The
default setting is bright.
The desired brightness level can be selected via
the ‘Dim’ switch located on the front panel.
TRANSMITTING
To transmit, press the PTT button on the
microphone. Hold the microphone 2-6 cm
from your mouth and slightly to one side so
your voice does not project directly into the
microphone. Speak at a normal voice level.
Your TX2720 has a built-in speech processor
which automatically controls the level of your
transmitted voice. It is not necessary to raise
your voice or shout into the microphone.
NOISE LIMITER
The NL key activates an extremely effective
noise limiter circuit which helps to eliminate
most electrical impulse interference caused by
engine ignition systems etc. This allows clearer
reception of weak signals even under noisy
electrical conditions.
When the NL key is selected, ‘N/L’ is displayed
on the LCD.
SCANNING
The TX2720 is fitted with a Scan function that
allows a group of user selected channels to be
scanned for activity. Your TX2720 has a Scan
memory which remembers which channels you
would like to Scan. By default your TX2720 is
supplied with all channels in the Scan memory.
To See Which Channels are Presently in
the Scan Memory
Select each channel one by one using the rotary
channel switch or by pressing the or keys
on the microphone and check to see if
is displayed to the lower right of the channel
number.
If is displayed, the channel is in the Scan
memory, otherwise the channel is not in the
Scan memory.
To Add or Remove a Channel from the
Scan Memory
Select the required channel, then press and
hold the SCAN key until a beep is heard. If
appears to the lower right of the channel
number, the channel has been added to the
Scan memory, otherwise it has been removed.

PAGE 6 INSTRUCTION MANUAL TX2720
To Scan
Adjust the Squelch control so the radio is quiet,
then briefly press the SCAN key. A high beep
will be heard, will flash on the display and
the channel numbers will change rapidly as
the radio begins scanning. If a signal is found,
the radio will pause on that channel and will
remain there as long as the channel remains
busy. Once the channel has been clear for 5
seconds, scanning will resume.
NOTE: You must have at least two channels
programmed into the Scan memory otherwise
the radio won’t scan.
To Change the Scan Direction
Press the or key. The radio will scan in the
direction of the selected channel key.
To Skip Over a Busy Channel
and Resume Scanning
Briefly press the or key. Scanning
will resume.
To Transmit on a Busy Channel
Wait for a break in the conversation, then press
the PTT switch. The radio will exit the Scan
mode and stay on the channel allowing you to
communicate with others on that channel.
To resume scanning briefly press the SCAN
key again.
NOTE: If the PTT is pressed while the radio is
scanning, it will be ignored and a low beep will
be heard when the PTT is released.
To Exit the Scan Mode Manually
Briefly press the SCAN key. will stop
flashing on the display.
NOTE: Excessive noise on a channel can cause
the scanning to pause on that channel even
if there is no signal there. If this only happens
on one channel, you may need to remove that
channel from the scan memory. If it happens
on all channels, you should try increasing the
squelch setting.
PRIORITY CHANNEL
The Priority channel is preset to channel 8
allowing it to be instantly recalled at the press
of a key.
To Use the Priority Channel
Simply press the Priority key at any time. The
radio will jump straight to channel 8. If Scan or
DW was selected, they will be cancelled.
To Return to the Previously Selected
Channel
Press the Priority key again.
DUAL WATCH
Dual Watch allows your TX2720 to monitor
both the Priority channel and another selected
channel by quickly switching between them.
Any signals received on the Priority channel
take precedence over signals on the selected
channel.
To use the Dual Watch feature, adjust the
Squelch control so the radio is quiet, select
your preferred channel using the or keys
or rotary channel switch then press the DW
key. ‘D/W’ will appear on the display and the
channel display will alternate between your
selected channel and the Priority channel.
If a signal is received on your selected channel,
the radio will pause on that channel but will
continue to switch to the Priority channel every
2 seconds and a brief interruption to the signal
will be noticed. Once the signal has gone,
normal Dual Watch switching will resume.
If a signal appears on the Priority channel at
any time, the radio will stop switching and will
remain on the Priority channel for as long as
the signal is present. Once the signal has gone,
normal Dual Watch switching will resume.
NOTE: If you press the PTT switch while Dual
Watch is selected, your TX2720 will transmit
on the selected channel. If you wish to talk on
the Priority channel, press the Priority key to
cancel the Dual Watch and switch straight to
the Priority channel.

TX2720 INSTRUCTION MANUAL PAGE 7
27 MHz CB CHANNEL ASSIGNMENTS
Channel Frequency Suggested Usage
1 26.965 MHz General Use
2 26.975 MHz General Use
3 26.985 MHz General Use
4 27.005 MHz General Use
5 27.015 MHz General Use
6 27.025 MHz General Use
7 27.035 MHz General Use
8 27.055 MHz Road Channel
9 27.065 MHz Emergency (1)
10 27.075 MHz General Use
11 27.085 MHz Call Channel
12 27.105 MHz General Use
13 27.115 MHz General Use
14 27.125 MHz General Use
15 27.135 MHz General Use
16 27.155 MHz General Use
17 27.165 MHz General Use
18 27.175 MHz General Use
19 27.185 MHz General Use
20 27.205 MHz General Use
21 27.215 MHz General Use
22 27.225 MHz General Use
23 27.255 MHz General Use
24 27.235 MHz General Use
25 27.245 MHz General Use
26 27.265 MHz General Use
27 27.275 MHz General Use
28 27.285 MHz General Use
29 27.295 MHz General Use
30 27.305 MHz General Use
31 27.315 MHz General Use
32 27.325 MHz General Use
33 27.335 MHz General Use
34 27.345 MHz General Use
35 27.355 MHz General Use
36 27.365 MHz General Use
37 27.375 MHz General Use
38 27.385 MHz General Use
39 27.395 MHz General Use
40 27.405 MHz General Use
(1) Legally Designated

PAGE 8 INSTRUCTION MANUAL TX2720
INSTALLATION
The TX2720 is supplied with a DIN mounting
bracket for mounting into a standard DIN sized
cavity in the vehicle’s console or dashboard.
Before installing the radio, ensure the DC cable
and antenna have been installed correctly (as
described further below) and the connectors are
accessible through the DIN cavity.
INSTALLING THE DIN MOUNT
To install the DIN mount you will need access
to the rear of the vehicle’s console.
1. Remove the four small front mounting bolts
from the front edges of the DIN mount
and separate the front frame from the DIN
surround.
2. Slide the DIN surround into the DIN slot in
the vehicle’s console and secure it in the
desired position by bending the folding tabs.
3. Slide the TX2720 radio into the front frame
so that the threaded holes in the chassis line
up with the holes in the front frame.
4. Secure the radio using the four 8 mm bolts
and washers provided.
5. Connect the DC connector and PL259
antenna (and rear microphone extension
lead if used) to the sockets on the radio’s
rear panel.
6. Slide the front frame back into the DIN
surround and secure it using the four small
front mounting bolts.
You can now refit the console to the vehicle.
DC POWER CONNECTIONS
The TX2720 is designed for 13.8 V DC negative
earth installations only (i.e. where the negative
side of the battery is connected to the frame
or chassis of the vehicle). There are two
recommended methods of installation. Please
refer to the following diagrams.
Radio remains On when the Ignition
switch is Off
Connect the radio’s negative (Black) lead to
the vehicle’s chassis or if preferred directly to
the battery’s negative terminal. Connect the
radio’s positive (Red) lead, via the 2 amp fuse,
to the battery’s positive terminal or to a point in
the fuse box that has +13.8 volts continuously
available.
The radio can now be switched ON or OFF
at any time using the switch on the volume
control.
Radio Turns On and Off with the
Ignition switch
Connect the radio’s negative (Black) lead to
the vehicle’s chassis or if preferred directly to
the battery’s negative terminal. Connect the
radio’s positive (Red) lead, via the 2 amp fuse,
to the accessory point in the fuse box. This
Radio remains ON when ignition switch is OFF
RED Fuse
Fuse
BLACK
Chassis
Car battery
Ingnition Switch
Radio turns ON and OFF with ignition switch
RED
BLACK
Chassis
Car battery
Ingnition Switch
To Radio
To Radio
DIN Surround
Folding Tabs
Front Mounting
Bolts
Front Frame
8 mm Bolts
and Washers
Front Frame

TX2720 INSTRUCTION MANUAL PAGE 9
point should supply +13.8 volts ONLY when the
ignition is switched ON or in the ACCESSORY
position
The radio should now switch ON and OFF
automatically with the vehicle’s ignition switch.
MICROPHONE
The TX2720 is fitted with two microphone
sockets – one on the front panel and one on
the rear. The 6 pin microphone connector can
be plugged into either socket. In fact, if the
situation requires it, two microphones can be
connected simultaneously.
Front
The front microphone socket is fitted with a
hard protective cover. The cover is a press fit. To
remove the cover insert a paper clip or similar
into the small slot in the edge of the cover and
lift the cover away from the panel. Retain the
cover in case you require it later on. Position
the microphone plug so the plastic tab faces
upwards then press the plug into the socket
until it ‘clicks’. Gently press the rubber strain
relief grommet into the hole surrounding the
socket so that the slot around the grommet fits
neatly inside the lip inside the hole.
Rear
If using the rear microphone connection you
should obtain the optional LEM6P rear
microphone extension lead. Mount the
extension lead’s socket on a convenient
location and feed the plug through the
dashboard to the DIN cavity.
Remove the rubber grommet from the rear
microphone socket and retain in case you
require it later on. Position the microphone plug
so the plastic tab faces upwards then press the
plug into the socket until it ‘clicks’.
Removing the Microphone
For the front panel connection, first squeeze
the grommet to disengage it from the slot then
slide it along the microphone cord.
Now squeeze the microphone plug’s plastic
tab towards the plug to unlock it while gently
pulling on the microphone cable. The plug
should release from the socket. If the plug
does not come out easily, the tab has not been
released fully – squeeze the tab again.
ANTENNA INSTALLATION
It is essential to install a good quality, high
efficiency, 27 MHz antenna. A poor quality
antenna or one not designed for the specific
frequency band will give very poor performance.
GME have a large range of suitable 27 MHz
antennas to suit most installations and
applications. We recommend you contact your
local GME dealer for advice.
After mounting the antenna, feed the antenna
cable to the DIN cavity in the vehicles console
or dashboard before mounting the radio.
Connect the antenna cable to the rear antenna
socket using the PL259 connector.
Radio remains ON when ignition switch is OFF
RED Fuse
Fuse
BLACK
Chassis
Car battery
Ingnition Switch
Radio turns ON and OFF with ignition switch
RED
BLACK
Chassis
Car battery
Ingnition Switch
To Radio
To Radio
Cable Entry
Screwdriver
Locking Lever – push
down to release plug
Microphone Cable

PAGE 10 INSTRUCTION MANUAL TX2720
ELECTRICAL
General
Complies With: AS/NZS4355:2006
Frequency Range: 26-30 MHz
Channel Set: Australian 27 MHz
CB (26.965 – 27.405
MHz)
Modulation: AM (A3E)
Supply Voltage: • 12 V DC nominal
• 10.8 – 15.6 V DC
range.
Frequency Error: ±1.4 kHz
Dual Watch: Monitor time – 250 ms
Scan Rate: 5 channels/second
Transmitter
Modulation
Frequency
Response: 300 Hz to 3 kHz, +1 – 3
dB
Max Modulation
Depth: 100%
Carrier Output
Power: 4 watts max
Spurious Emissions: < -26 dBm
Receiver
Demodulated
Frequency
Response: 300 Hz to 3 kHz, +1–3 dB
Receive Sensitivity
for 12 dB SINAD @
30% Modulation: -110 dBm
Max Squelch: < -65 dBm
Adjacent Channel
Sensitivity: ≥ 55 dB
Spurious Response
Immunity: ≥ 55 dB
Conducted
Spurious
Radiation: ≤ -57 dBm
Audio Output
Power 8 Ohms: 2.5 watts
MECHANICAL
Dimensions (mm): 51 (H) x 94 (D) x 170 (W)
Weight: 450 grams
ENVIRONMENTAL
Temperature
Range: -0°C to + 55°C
The TX2720 will operate over the 26-30 MHz
frequency range. For information specific to
frequencies outside of the Australian CB bands,
please refer to the appropriate amendment, or
contact GME at: [e-mail]
SPECIFICATIONS
Specifications are typical unless otherwise indicated and may be subject to change
without notice or obligation.
NOISE SUPPRESSION
27 MHz CB radio can be prone to electrical
and ignition interference. The reason is that
electrical noise is a form of AM transmission
similar to that used by your radio and your
radio’s receiver is very sensitive. In most
cases, ignition noise can be greatly reduced
or eliminated by selecting the Noise Limiter
(NL) key on the radio. In some severe cases
additional suppression may need to be fitted
to the ignition system of your vehicle in
which case we recommend you consult an
auto electrician for advice specific to your
installation.

TX2720 INSTRUCTION MANUAL PAGE 11
STANDARD COMMUNICATIONS CONTRACT WARRANTY
AGAINST DEFECTS
This warranty against defects is given by
Standard Communications Pty Ltd ACN 000
346 814 (We, us, our or GME). Our contact
details are set out in clause 2.7. This warranty
statement only applies to products purchased
in Australia. Please contact your local GME
distributor for products sold outside of
Australia. Local distributor details at www.gme.
net.au/export.
1. Consumer guarantees
1.1 Our goods come with guarantees that
cannot be excluded under the Australian
Consumer Law. You are entitled to a
replacement or refund for a major failure
and for compensation for any other
reasonably foreseeable loss or damage.
You are also entitled to have the goods
repaired or replaced if the goods fail to be
of acceptable quality and the failure does
not amount to a major failure.
1.2 To the extent we are able, we exclude
all other conditions, warranties and
obligations which would otherwise be
implied.
2. Warranty against defects
2.1 This Warranty is in addition to and does
not limit, exclude or restrict your rights
under the Competition and Consumer Act
2010 (Australia) or any other mandatory
protection laws that may apply.
2.2 We warrant our goods to be free from
defects in materials and workmanship for
the warranty period (see warranty table)
from the date of original sale (or another
period we agree to in writing). Subject
to our obligations under clause 1.2, we
will at our option, either repair or replace
goods which we are satisfied are defective.
We warrant any replacement parts for the
remainder of the period of warranty for the
goods into which they are incorporated.
2.3 To the extent permitted by law, our sole
liability for breach of a condition, warranty
or other obligation implied by law is limited
(a) in the case of goods we supply, to any
one of the following as we decide -
(i) the replacement of the goods or
the supply of equivalent goods;
(ii) the repair of the goods;
(iii)the cost of repairing the goods or
of acquiring equivalent goods;
(b) in the case of services we supply, to
any one of the following as we decide
–
(i) the supplying of the services again;
(ii) the cost of having the services
supplied again.
2.4 For repairs outside the warranty period,
we warrant our repairs to be free from
defects in materials and workmanship for
three months from the date of the original
repair. We agree to re-repair or replace (at
our option) any materials or workmanship
which we are satisfied are defective.
2.5 We warrant that we will perform services
with reasonable care and skill and agree
to investigate any complaint regarding
our services made in good faith. If we are
satisfied that the complaint is justified,
and as our sole liability to you under this
warranty (to the extent permitted at law),
we agree to supply those services again at
no extra charge to you.
2.6 To make a warranty claim you must before
the end of the applicable warranty period
(see warranty table), at your own cost,
return the goods you allege are defective,
provide written details of the defect, and
give us an original or copy of the sales
invoice or some other evidence showing
details of the transaction.

Part Number: 310576 Drawing Number: 46557-4
2.7 Send your claim to:
Standard Communications Pty Ltd.
PO Box 96 Winston Hills,
NSW 2153, Australia.
Tel: [phone] Fax: [phone]
Email: [e-mail]
2.8 If we determine that your goods are
defective, we will pay for the cost of
returning the repaired or replaced goods to
you, and reimburse you for your reasonable
expenses of sending your warranty
claim to us.
3. What this warranty does not cover
3.1 This warranty will not apply in relation to:
(a) goods modified or altered in any way;
(b) defects and damage caused by use
with non Standard Communications
products;
(c) repairs performed other than by our
authorised representative;
(d) defects or damage resulting from
misuse, accident, impact or neglect;
(e) goods improperly installed or used
in a manner contrary to the relevant
instruction manual; or
(f) goods where the serial number has
been removed or made illegal.
4. Warranty period
4.1 We provide the following warranty on
GME and Kingray products. No repair or
replacement during the warranty period
will renew or extend the warranty period
past the period from original date
of purchase.
A division of Standard Communications Pty Ltd.
Head Office: PO Box 96, Winston Hills, NSW 2153, Australia.
New Zealand: PO Box 58, 446 Botany, Auckland 2163 (09) 274 0955
All other international enquiries email: [e-mail]
PRODUCT TYPE WARRANTY
PERIOD
27 MHz land and
marine radios
1 year