GME G-COM GX400 User manual

GX400
27 MHz RADIO
INSTRUCTION MANUAL

2 INSTRUCTION MANUAL GX400
CONTENTS
WARNING/SAFETY INFORMATION..................................................................................................... 3
INTRODUCTION ................................................................................................................................ 3
INSTALLATION GUIDELINES............................................................................................................... 3
SUPPLIED WITH................................................................................................................................. 3
FEATURES......................................................................................................................................... 4
SWITCHING BANDS .......................................................................................................................... 4
CONTROLS........................................................................................................................................ 4
GENERAL OPERATION....................................................................................................................... 6
Volume on/off ........................................................................................................................... 6
Squelch control ......................................................................................................................... 6
Channel selection...................................................................................................................... 6
Display brightness ..................................................................................................................... 6
Transmitting.............................................................................................................................. 6
Noise Limiter............................................................................................................................. 6
Scanning................................................................................................................................... 7
Priority channels (PR1/PR2)........................................................................................................ 8
Key Lock function...................................................................................................................... 8
OPERATION ON THE AUSTRALIAN MARINE BAND ............................................................................. 8
Dual Watch (marine mode)........................................................................................................ 8
Triple Watch (marine mode)....................................................................................................... 9
Triple Watch features ................................................................................................................ 9
Marine Band procedures.......................................................................................................... 10
Emergency procedures............................................................................................................. 10
OPERATION ON THE CB BAND ........................................................................................................ 11
Dual Watch (CB mode)............................................................................................................ 11
Triple Watch (CB mode)........................................................................................................... 12
Triple Watch features .............................................................................................................. 12
INSTALLATION ................................................................................................................................ 14
General................................................................................................................................... 14
Installing the unit .................................................................................................................... 14
DC connections ....................................................................................................................... 15
Antenna installation ................................................................................................................ 16
Extension speaker ................................................................................................................... 16
Noise suppression ................................................................................................................... 16
Disconnecting the microphone................................................................................................. 17
SPECIFICATIONS ............................................................................................................................. 18
STANDARD COMMUNICATIONS WARRANTY AGAINST DEFECTS ..................................................... 19

GX400 INSTRUCTION MANUAL 3
WARNING/SAFETY INFORMATION
The GX400 is a radio transmitting device.
•Do not transmit near electrical blasting equipment or in explosive atmospheres.
•Do not allow children to operate a radio transmitter unsupervised.
•The antenna used for this radio must be properly installed and maintained and must
provide a separation distance of at least 34 cm (13.4 inches) from all persons and must
not be collocated or operated in conjunction with any other antenna or transmitter.
Never transmit if any person is closer than the specified distance to the antenna.
•Changes or modifications to this product or use of accessories not expressly approved by
GME, or operation of this product in any way other than as provided in the GME Owner’s
Manual could void your authority to operate this product.
INTRODUCTION
Congratulations. You have just purchased one of the most technically advanced 27 MHz radios
in the world.
The GME GX400 is a 27 MHz AM radio that combines both Marine and Citizens Band functions
into the one radio. The GX400 has a number of enhanced features including fully user
programmable channel scanning, safety channel selection (Channel 88 in marine mode, Channel
8 in CB mode), speaker microphone, two Priority channels and a backlit Liquid Crystal Display
(LCD) with dimming function.
With its compact size and IPX7 design it can easily be installed into almost any mounting
location in your boat, motor vehicle, motor cycle etc.
Please read this manual thoroughly to ensure you get the best from the GX400’s features.
For users in New Zealand, United States of America, Canada, South Africa or Papua New Guinea,
please refer to amendment for local frequencies, channel allocations and licensing requirements.
INSTALLATION GUIDELINES
•Do not install the radio near an airbag or in an area where an airbag may deploy. If an
airbag is obstructed by the radio, it may not deploy as expected. It could also propel the
radio with enough force to cause serious injury.
•Avoid touching the heat sink at the rear of the radio while the radio is in use. The heat sink
can become hot during prolonged use.
•Do not install the radio in front of a vehicle heater. The radio requires a cool airflow over the
rear heat sink when transmitting to maintain efficiency.
•Do not make unapproved modifications to the radio. Such modifications could void the
warranty and cause the radio to operate outside its approved specifications.
SUPPLIED WITH
Cabin cover
Mounting bracket and gimbal knobs
Mounting hardware
Microphone bracket
DC power lead
Instruction manual

4 INSTRUCTION MANUAL GX400
FEATURES
• Ingress protection to IPX7*
• LCD with lamp dimming function
• Rotary squelch control
• Channel scanning with memory
• Two user programmable Priority channels
• Dual Watch and Triple Watch functions
• Advanced noise limiter (NL) circuitry
• Surface mount technology
• User selection of Australian 27 MHz marine or 27 MHz CB channels
• Safety channel 88 for marine application (channel 8 for CB application)
*Refer: http://www2.gme.net.au/IPRatings
SWITCHING BANDS
The GX400 is capable of operating on both the Australian 27 MHz Marine Band and the
Australian 27 MHz Citizens Band. This makes your radio very versatile in that it can be used in
your vehicle, on a boat or even on a motorcycle or tractor.
When you first install your GX400, it should default to the 27 MHz Marine Band. When
operating on the Marine Band the radio will display channels 68 – 98 and the key will default
to safety Channel 88.
To select the CB band, turn the radio OFF, then press and hold the DW key while turning the radio
on again. The radio will now display channels 1 – 40 and the key will default to road Channel 8.
Repeat the sequence above to return to the Marine Band.
NOTE: Class licence 2001 prohibits the use of a Maritime Ship Station for land-based
communications. When the Marine Band is selected, the GX400 should only be used for
Ship-to-Ship, Ship-to-Shore or Shore-to-Ship communications.
CONTROLS
Front Panel
PR 1
PR 2
SCN
NL
DW
TW
SQL
VOL
27MHz TRANSCEIVER
Priority 1
Squelch
Priority 2
Dual Watch
Noise Limiter
Triple Watch
Scan
Channel Down
Channel Up
Safety Channel
Volume
Mic Socket
Power/
Dim
Key
Lock
M
B

GX400 INSTRUCTION MANUAL 5
Rear Panel
MC616 Microphone
Priority 1
Priority 2
Dual Watch Triple Watch
Key
Lock
Noise Limiter
Transmit
Safety
Channel Scan
Memory
Scan
RX Busy
Channel
Display
LCD
Rear Mic Socket
Antenna Socket
Extension Speaker
3.5 mm
Programming
2.5 mm (factory use only)
DC
Connector
Speaker
Bollard
Up
Scan
Down
Microphone
PTT
Safety
Channel
Front Rear

6 INSTRUCTION MANUAL GX400
GENERAL OPERATION
VOLUME ON/OFF
To turn the GX400 on, briefly press the key.
To adjust the volume, rotate the volume control. Rotate the volume control clockwise to increase
the volume or counter-clockwise to reduce the volume.
NOTE: At minimum volume setting there is still sufficient volume to be heard in a quiet cabin
environment.
To turn the GX400 off, press and hold the key again.
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 disappears. If there are signals on the
channel, you should wait until the channel is clear (or select a quiet channel) before adjusting
the squelch.
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 action 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 by briefly pressing the or keys. The selected channel is
displayed on the LCD. Press and hold either key to quickly advance upwards or downwards
through the channels. Release the key when the required channel is displayed.
DISPLAY BRIGHTNESS
The LCD has three brightness levels to provide suitable lighting for day or night use.
To adjust the brightness
Briefly press the key to cycle through the display brightness settings. The display brightness
will cycle through Off, Dim and Bright. If the radio is switched off the selected brightness level
will be retained in memory and will be restored when the radio is switched on again.
TRANSMITTING
To transmit, press the PTT 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 GX400 has a build-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. Release the PTT to receive.
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 noise limiter is
selected, ‘NL’ is displayed on the LCD.

GX400 INSTRUCTION MANUAL 7
SCANNING
The Scan function allows a group of channels to be scanned for activity. Channels to be scanned
can be programmed into the scan memory by the user.
By default your GX400 is supplied with all channels in the scan memory. You can remove or add
channels as desired.
To determine if a channel is stored in the scan memory
Select the required channel using the or key then check to see if ‘M’ is displayed to the
right of the channel number. If ‘M’ is displayed, the channel is in the scan memory otherwise the
channel is not in the scan memory.
Channel in scan memory Channel not in scan memory
To add or remove a channel from the scan memory
Select the required channel, then press and hold the SCN key until a beep is heard. If the
channel was not in the scan memory, it will be added and ‘M’ will appear. If the channel was
currently in the scan memory, it will be removed and ‘M’ will disappear.
To scan
Adjust the Squelch control so the radio is quiet then briefly press the SCN key. A high beep will
be heard, ‘SCAN’ will appear in 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 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 key. 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 SCN 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.

8 INSTRUCTION MANUAL GX400
To exit the Scan mode manually
Briefly press the SCN key. ‘SCAN’ will disappear from the display.
NOTE: Excessive noise on a channel can cause the scanner to pause on that channel even if
there is no signal there. If this only happens on one channel, you may need to consider removing
that channel from the scan memory. If it happens on all channels, you should try increasing the
squelch setting.
PRIORITY CHANNELS (PR1/PR2)
There are two Priority channel memories labelled PR1 and PR2 that allow you to store channels
for instant recall.
To store a Priority channel, select the required channel using the or keys, then press and
hold the required priority key (PR1 or PR2) to store the channel under the designated key.
To recall a Priority channel, briefly press either PR1 or PR2. The radio will instantly jump to the
designated channel and the channel number will be displayed along with the associated ‘PR1’
or ‘PR2’ icon.
KEY LOCK FUNCTION
The Key Lock allows most of the keys to be locked to prevent accidental key presses from
changing the channel or the radio’s settings. While the keys are locked only the Volume,
Squelch and button controls are available.
To lock the keys, press and hold the key for 1 second. The icon is displayed and a
high beep is heard.
To unlock the keys, press and hold the key again. The icon disappears and a low
beep is heard.
OPERATION ON THE AUSTRALIAN MARINE BAND
Channel 88
Channel 88 is the designated 27 MHz marine safety channel and in many areas is monitored by
coastal-watch and rescue organisations for emergency and safety purposes.
When making radio calls, you should make initial contact on Channel 88 then switch to another
channel to continue your conversation. This leaves Channel 88 free for other calls or emergencies.
Safety channel key
Your GX400 has a dedicated Safety channel key to allow instant access to Channel 88.
Pressing this key cancels all other functions such as Scan or Dual Watch and takes you straight to
Channel 88. When Channel 88 is selected using the key, ‘SAFETY’ is displayed on the LCD.
To return to normal channel operations briefly press the key again. ‘SAFETY’ will disappear
from the display, the radio will return to the previously selected channel. Alternatively press the
or keys to select a different channel.
DUAL WATCH (MARINE MODE)
Dual Watch in the Marine mode allows your GX400 to monitor both Channel 88 and another
selected channel by quickly switching between them. Any signals received on Channel 88 take
precedence over signals on the selected channel.

GX400 INSTRUCTION MANUAL 9
To use the Dual Watch feature, adjust the Squelch control so the radio is quiet, select your
preferred working or club channel then press the DW key. ‘DW’ will appear on the display and
the channel display will alternate between Channel 88 and your selected channel.
If a signal is received on your selected channel, the radio will pause on that channel but will
continue to switch to Channel 88 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 Channel 88 at any time, the radio will stop switching and will remain on
Channel 88 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 GX400 will transmit on
the selected channel. If you wish to talk on Channel 88, press the key to cancel the Dual
Watch and switch straight to Channel 88.
TRIPLE WATCH (MARINE MODE)
The Triple Watch function is an extension of the Dual Watch feature. It allows the GX400 to
monitor three channels – Channel 88, the selected channel and a Priority channel. Each channel
is scanned equally for signals with priority given first to Channel 88, then the Priority channel
and lastly the selected channel.
When Triple Watch is selected, the ‘TW’ icon is displayed. The Priority channel used is the one
stored in the PR1 memory.
To use the Triple Watch mode, first program your Priority channel into the PR1 memory then
select your preferred working channel using the or keys. Now briefly press the TW key.
A high beep will be heard, ‘TW’ will appear and the channel display will alternate between
Channel 88, your selected channel and your Priority channel.
To cancel Triple Watch
Briefly press the TW key. A low beep will be heard and ‘TW’ will disappear from the display.
TRIPLE WATCH FEATURES
If a signal appears on Channel 88
The radio will switch immediately to Channel 88 and ‘88’ will be displayed. At this point the
selected channel and the PR1 channel are no longer being monitored because Channel 88 has
highest priority. During this time the PTT may be pressed for normal transmissions on Channel 88.
Once Channel 88 has become inactive for 2 seconds the Triple Watch function will resume.
If a signal appears on the PR1 channel
Scanning will pause on the PR1 channel but Channel 88 will continue to be monitored every 2
seconds (the selected channel is not monitored). During this time the PTT may be pressed for
normal transmissions on the PR1 channel (monitoring of Channel 88 ceases while transmitting).
Once the PR1 channel has become inactive for 2 seconds Triple Watch will resume.
If a signal appears on the selected channel
Scanning will pause on the selected channel but Channel 88 and the PR1 channel will
continue to be monitored every 2 seconds. During this time the PTT may be pressed for normal
transmissions on the selected channel (monitoring of Channel 88 and the Priority channel ceases

10 INSTRUCTION MANUAL GX400
while transmitting). Once the selected channel has become inactive for 2 seconds the Triple
Watch will resume.
To transmit on the selected channel while Triple Watching
Simply press the PTT. The Triple Watch function will pause during the transmission and remain
paused until 2 seconds after all activity has ceased on the channel. Triple Watch will then resume.
To transmit on the Priority channel while Triple Watching
Briefly press the PR1 key. The PR1 channel will then become the selected channel. Now press
the PTT and transmit in the usual way. When your conversation has ended you may use the
or keys to re-select your preferred channel.
To transmit on Channel 88 while Triple Watching
Press the button. Triple watch will be cancelled and the radio will switch straight to Channel
88 (and ‘SAFETY’ will be displayed). Now press the PTT and transmit in the usual way. When
your conversation has ended, press the button to deactivate the SAFETY channel and press
the TW key to resume Triple Watching.
MARINE BAND PROCEDURES
Most calls to other vessels or stations are initiated on Channel 88. After listening to ensure
Channel 88 is clear, call the other station as follows, repeating both call signs three times.
e.g. “Coast Guard, Coast Guard, Coast Guard. This is – Sea Spray, Sea Spray, Sea Spray, Over”
Once contact has been established, move straight to another channel (e.g. 91 or 94) to continue
your conversation, leaving Channel 88 clear for emergencies or further calls. Don’t forget to
return to Channel 88 when you have finished (or select Dual Watch on your radio) otherwise
you may miss other calls meant for you.
EMERGENCY PROCEDURES
All emergency calls should be made on Channel 88. There are three main types of emergency call.
1. “MAYDAY, MAYDAY, MAYDAY”
This call should be used when you are in grave or imminent danger and require immediate
assistance. You should call MAYDAY three times followed by your vessel’s name or call sign
three times. Then state your position, a brief description of your vessel, the nature of the
emergency, the number of people on board and their condition. If you hear no reply, repeat
the call at short intervals because someone may be able to hear you but you might not be
able to receive their reply.
After contact has been made, follow any instructions given to you.
2. “PAN, PAN, PAN”
Use this call when an emergency situation exists but there is no immediate danger. The call
should be made in the same way as the MAYDAY call. If you hear no reply, repeat the call at
regular intervals.
3. “SECURITE, SECURITE, SECURITE” (Pronounced Say-cure-e-tay)
This call is used to warn shipping of dangers or hazards, e.g. Bad weather, container adrift etc.
The call may be made to a local monitoring station or to all ships in the area.