M-tech MT-300 User manual

i
M-TECH RADIO
MODEL MT-300
DSC VHF Marine Radio
Instruction Manual

ii
Table of Contents
Section 1: Installation..................................................................1
Introduction................................................................................... 1
Powering Your Radio ................................................................ 1
Auxiliary Wires ......................................................................... 1
Bracket Installation.................................................................. 2
Antenna.......................................................................................... 3
How to Make a Distress Call........................................................ 4
Section 2: Basic Radio Operation................................................5
Using the Keypad.......................................................................... 5
Power/Volume............................................................................ 6
Squelch....................................................................................... 6
H/L (High/Low).......................................................................... 6
WX (Weather)............................................................................ 6
16/9 (Priority Channel) ............................................................. 6
SCN (Scan)................................................................................. 6
MEM (Memory) ......................................................................... 7
CALL.......................................................................................... 7
DISTRESS ................................................................................. 7
SELECTOR................................................................................ 7
PTT (Press to Talk) ................................................................... 7
DSC Calling vs. non-DSC Calling................................................ 7
What is a DSC call?................................................................... 7
How DSC works......................................................................... 8
Simplex or Duplex..................................................................... 8
MMSI (Maritime Mobile Service Identity).................................. 8
MMSI Setup............................................................................... 9
Choosing a Channel .................................................................... 10
Making a Call.............................................................................. 10
Receiving a Call........................................................................... 11
Section 3: Advanced Operation.................................................13
Calls.......................................................................................... 13
Transmission ........................................................................... 13
AllShips Call........................................................................ 13
Directory Call ...................................................................... 14
Distress Call ........................................................................ 14
Last Call............................................................................... 16
New Call............................................................................... 16
Reception.................................................................................. 18
AllShips Call........................................................................ 18
Distress Call ........................................................................ 18
Geographic Call................................................................... 18
Individual Call..................................................................... 19

iii
Channels.................................................................................. 19
Channel Bank.......................................................................... 19
Directory .................................................................................. 20
Storing/Editing MMSI Data ............................................... 20
DSC Monitor............................................................................ 21
GPS Operation......................................................................... 22
H/L............................................................................................ 22
Memory Operation .................................................................. 22
Position Send/Request ............................................................ 23
Transmission ....................................................................... 23
Reception.............................................................................. 24
Priority Channel (16/9)........................................................... 25
PTT (Push To Talk)................................................................. 25
Scan.......................................................................................... 25
Weather (Wx)........................................................................... 27
Frequency Charts & Usage .......................................................28
FCC Radio License and MMSI Number Information
In U.S. waters, vessels which are not required to carry radio equipment
are not required to have an FCC (Federal Communications Commis-
sion) ship station license for a VHF marine radio.
However, any vessel required to carry a marine radio on an interna-
tional voyage, carrying a HF single side band radio telephone or ma-
rine satellite terminal must have an FCC license.
License application forms for ship and land stations can be downloaded
free from the FCC web site at this address: www.fcc.gov/formpage.html.
You may also order copies of these forms by calling the FCC Forms Dis-
tribution Center at 1-800-418-3676.
At this time, the FCC does not require recreational boaters to have a
ship radio station call sign. The U.S. Coast Guard recommends using
the boat's registration number and state.
The BoatU.S. MMSI Program has been certified by both the Federal
Communications Commission (FCC) and the U.S. Coast Guard to as-
sign MMSI numbers to vessels with DSC capable radios. To obtain and
register your free MMSI number, the Coast Guard recommends logging
onto http://www.boatus.com/mmsi/ and following the instructions.

iv
FCC Digital Device Compliance
This device complies with Part 15 of the U.S. Federal Communi-
cations Commission (FCC) Rules. Operation is subject to the fol-
lowing two conditions: (1) this device may not cause harmful in-
terference, and (2) this device must accept any interference re-
ceived, including interference that may cause undesired opera-
tion.
Changes or modifications not expressly approved by the manu-
facturer could void the user's authority to operate the equipment.
Note:
This equipment has been tested and found to comply with the
limits for a Class B digital device, pursuant to Part 15 of the
FCC Rules. These limits are designed to provide reasonable pro-
tection against harmful interference in a residential installation.
This equipment generates, uses and can radiate radio frequency
energy and, if not installed and used in accordance with the in-
structions, may cause harmful interference to radio communica-
tions. However, there is no guarantee that interference will not
occur in a particular installation. If this equipment does cause
harmful interference to radio or television reception, which can
be determined by turning the equipment off and on, the user is
encouraged to try to correct the interference by one or more of
the following measures:
•Reorient or relocate the receiving antenna.
•Increase the separation between the equipment and receiver.
•Connect the equipment into an outlet on a circuit different from
that to which the receiver is connected.
•Consult the factory customer service department for help.

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FCC Radio Frequency
Compliance Requirements and Warnings
When operating your marine radio transceiver, you should know that
the antenna radiates radio frequency (RF) energy. This radio was de-
signed to meet the FCC’s rules and regulations for the maximum per-
missible exposure to radio frequency energy. This design was tested
and found to be compliant with the strict requirements established by
the FCC.
DO NOT operate the radio without a proper antenna attached, because
this may damage the radio and may also cause you to exceed FCC RF
exposure limits. Antenna types suited for this radio are described in
the installation section.
DO NOT transmit for more than 50% of the total radio use time.
Transmitting more than 50% of the time can cause FCC RF exposure
compliance requirements to be exceeded. The radio is transmitting
when the “TX indicator” is displayed on the screen. You can cause the
radio to transmit by pressing the "PTT" (Push To Talk) switch.
IMPORTANT: The antenna(s) used for this transmitter must be in-
stalled to provide a separation distance of at least 91 cm (37 inches)
from all persons (including passengers). The antenna(s) must not ex-
ceed an antenna gain of 3 decibels (dB) and must not be co-located or
operating in conjunction with any other antenna or transmitter.

1
Section 1: Installation
Introduction
Thank you for purchasing the M-Tech MT-300 DSC VHF Radio. We
know you’re anxious to try it out, but first, let us explain how this man-
ual can help you get the most out of your new radio.
We have designed this book so you don’t have to read the whole thing
from front to back to find the information you want. At the start of each
segment, we’ll tell you what content is coming up next. If it’s a concept
you're already familiar with, we’ll show you where to find the next im-
portant topic.
We lead off the manual with proper Distress Call procedures on page 4.
We put it at the front of the book to make it easy to find in case of an
emergency.
The first section covers MT-300 installation and specifications.
The second section, Basic Radio Operation, goes over some basic func-
tions of the radio and includes instructions on how to set up your MMSI
(Maritime Mobile Service Identity) number. You can't make a call
without it! To jump to MMSI setup, flip to page 8. To acquire a free
MMSI number, see the web address on the bottom of page ii.
The third section, Advanced Radio Operation, offers more detailed in-
formation about the radio's features. The section will touch on all as-
pects of the radio's functionality, providing clear and complete explana-
tions via a convenient alphabetical layout.
Let’s get started!
Powering Your Radio
(Power Supply cable – red and black wires)
The unit works from a 12-volt electrical system. You may attach the
radio to a 12-volt battery or to an auxiliary power panel.
If possible, keep the power cable away from other boat wiring, especially
the engine's wires. This will provide the best isolation from electrical
noise. The power cable has two wires, red and black. Red is the positive
lead, black is negative or ground. Make sure to attach the in-line fuse
holder to the red lead
as close to the power source as possible.
Auxiliary Wires
The white and black auxiliary wires on the back of the unit connect
your radio to an external speaker. Connect the white (+) wire to the
speaker's positive lead, and connect the black (–) wire to the speaker's
negative lead.

2
The remaining auxiliary wires are used for DSC (Digital Selective Call-
ing) service, where the radio can exchange latitude and longitude posi-
tion information with a GPS (Global Positioning System) receiver in
NMEA 0183 format.
Wiring to transmit NMEA information
to a GPS receiver.
Wiring to receive NMEA position information
from a GPS receiver.
Caution
All of the auxiliary wires have bare ends for easier installation.
The bare ends on any unused wires could cause an electrical
short if left exposed. To prevent this, you should cover the indi-
vidual wire ends – either by capping them with wire nuts or
wrapping them with electrical tape.
Bracket Installation
Mount the unit in any convenient location, provided there is clearance
behind the unit when it's tilted for the best viewing angle. You should
also make sure there is enough room behind the unit to attach the
power, antenna and auxiliary cables. Pick a location far enough from
any compass to avoid compass deviation caused by the speaker magnet.
The radio must be installed at least three feet from the antenna. Make
sure there is space nearby to hang the mic clip.
Holes in the gimbal bracket's base allow wood screw or through-bolt
mounting. You may need to place a piece of plywood on the back side of
thin fiberglass panels to reinforce the panel and secure the mounting
hardware. We suggest that you use stainless steel screws for installa-
tion.
Ground – (Red) To Radio
To GPS unit
NMEA Receive + (Brown)
Shield (Ground)
Receive + NMEA Transmit + (Orange)
Shield – (Ground) Ground – (Yellow)
To GPS unit To Radio
Transmit +

3
Install the gimbal bracket, which looks similar to the one pictured here. Place
the bracket so the arms slope toward the radio's front.
Once a location is determined, use the bracket as a template and mark
the mounting holes. Screw the bracket to the mounting surface. Be sure
to leave enough slack in the cables to allow tilting the unit.
Attach the unit to the gimbal bracket using the supplied gimbal knobs
and washers. Attach the cables and the unit is ready to use.
Antenna
A good antenna installation will optimize the performance of your ma-
rine radio. There is no height requirement for antenna installation, but
the higher it is mounted, the better the reception. That's because ma-
rine VHF radio signals travel only on a "line of sight" basis. An ideal
installation will give the antenna a clear view of the horizon in all di-
rections.
The antenna may be mounted on a gunwale, rail or on flat surfaces like
a deck, roof or bulkhead. In the case of some sailboats and powerboats,
it may be attached to a mast or mast-like structure.
When installing your VHF marine antenna, be sure to keep it at least
three feet away from any other antenna or metal object. The antenna
also must be installed three feet away from the radio, and at least three
feet from any passengers or crew. Refer to the antenna manufacturer's
instructions for further installation information. You must also make
Front
Screw
mounting
hole

4
sure your antenna and its installation complies with all local and fed-
eral regulations. Never operate your radio unless it is connected to the
antenna.
The antenna must not exceed an antenna gain of 3 decibels (dB). The
antenna cable requires a PL259 connector, and the cable connects at
the back of the radio. For installations less than 25 feet, use RG58 co-
axial cable. For installations greater than 25 feet, use RG-8/U coaxial
cable.
WARNINGS:
Using an antenna with gain greater then 3 dB can damage the
radio and exceed the safe exposure limits for radio frequency
(RF) energy.
Also, the energy from any VHF radio antenna can be harmful,
even one properly rated at 3 dB of gain! Do not come in contact
with the antenna while a transmission is being sent. Be sure
the antenna is installed where it is separated from people by
at least 3 feet of space.
How to Make a Distress Call
Speak slowly, clearly and calmly.
1. Select VHF Channel 16.
2. Press microphone button: "MAYDAY — MAYDAY— MAYDAY."
3. "THIS IS [your ship ID]."
4. "MAYDAY [your ship name]."
5. Tell where you are — what navigational aids or landmarks are near.
6. State the nature of your distress.
7. Give number of persons aboard and condition of any injured.
8. Estimate present seaworthiness of your ship.
9. Briefly describe your ship — meters, type, color, hull.
10. "I WILL BE LISTENING ON CHANNEL 16."
11. End message by saying "THIS IS [ship name/call sign] OVER."
12. Release the PTT key and listen. Someone should answer. If not, re-
peat call, beginning at Item 3 above.
WARNING
The following types of communication are prohibited by the
FCC: false distress calls; calls to any boat — excluding emer-
gencies and radio tests; calls to or from a vessel on land and
obscene or profane language. Using obscene or profane lan-
guage could result in a fine of up to $10,000.

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Section 2: Basic Radio Operation
This section addresses the radio’s basic operations, which includes
MMSI (Maritime Mobile Service Identity) number setup. If you already
have your MMSI number programmed into the radio and have a strong
understanding of the radio's basic functions, move on to Section 3: Ad-
vanced Radio Operation.
We're going to kick off the operation section with a brief description of
the radio's basic functions. That will be followed by some important
information on Digital Selective Calling and basic instructions on how
to make and receive calls.
Using the Keypad
The keypad has six keys: H/L (Hi/Lo), WX (Weather), 16/9 (Priority
Channels), SCN (Scan), MEM (Memory), CALL (Call). When you press
any of the keys a tone will sound. If you push a key and a 3-beep tone
sounds, there is an error or the function is not supported by the radio.
You’ll notice several functions require you to hold down a key for a few
seconds. In those cases, a single beep sounds, then, after a few mo-
ments, a second beep will be heard to let you know you have success-
fully changed the mode.
The M-Tech MT-300 VHF Marine Radio.

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Power/Volume
The volume knob at the top right of the radio’s face is used to power up
the MT-300. Turn the knob clockwise to turn on the radio. The unit will
start on Ch. 2, then switch to Ch. 16, its default priority channel.
Squelch
Squelch, the bottom knob on the radio’s face, helps the unit screen out
radio traffic resulting from signals that are too weak to transmit any-
thing but noise. To adjust the squelch, turn it to the left until noise can
be heard. Turn it back to the right until the noise is eliminated.
H/L (High/Low)
The H/L key gives you control over the radio's wattage. The high-end is
25 Watts. The low-end is 1 Watt. If the LO ANNUNCIATOR is off, the radio
will transmit at 25 Watts.
WX (Weather)
Dark clouds on the horizon? Press the WX key to enter the WX (WEATHER)
MODE and get the latest weather information. Use the Selector to
change the WX channel.
16/9 (Priority Channel)
The 16/9 key is used to switch between priority channels. It also allows
you to exit various operation modes, ignore incoming calls and cancel
outgoing calls.
NOTE
Ch. 16 and Ch. 9 may only be used to make initial contact with a
vessel and nothing more. When there is an emergency, all Distress
calls will be broadcast on Ch. 16.
SCN (Scan)
The SCN (scan) key allows you to monitor numerous channels at the
same time. Scanning options include: PRIORITY SCAN,MEMORY SCAN AND
ALLSCAN.
ID
Annunciator
Character
field position
Channel
DSC
Monitor
Memory Annunciator
USA
Channel
Bank

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MEM (Memory)
The MEM key may be used to initiate a Memory Scan and gives you the
option of adding or deleting channels from the radio's scan list memory.
CALL
By pressing the CALL key you can make a new call, return the last in-
coming call, place a call to all ships or to one of up to 10 stored MMSI
numbers from a saved directory.
DISTRESS
By lifting up the red cover and holding down the DISTRESS button for
three seconds, you will send a distress call to the Coast Guard and any
other ship within range of you.
Selector
Use the Selector to scroll through the channels and various menu op-
tions.
PTT (Press to Talk)
The PTT key is the talk button on the microphone. Press and hold it
down to talk when making or receiving a call.
DSC Calling vs. non-DSC Calling
The MT-300 supports two types of calls, Digital Selective Calls (DSC)
and non-Digital Selective Calls. A non-DSC call is the traditional
method where an individual hails another vessel on Ch. 16, then asks
the other party to switch to a working channel set aside for the desired
communication type. Once they have left Ch. 16 and the selected work-
ing channel is clear, the individual hails the vessel again to initiate
communication.
What is a DSC call?
A relatively new technology, digital selective calling (DSC) gives you
the capability to dial another boat directly via the vessel's MMSI (Mari-
time Mobile Service Identity) number, which functions much like a
phone number. Digital Selective Calling simplifies the calling process,
because you don't have to hail the vessel on Ch. 16 nor do you have to
verbally direct them to the working channel you want them to switch to
for communication. When their DSC radio receives your call, it auto-
matically will switch to the channel you selected for communication.
The primary reason DSC was created was to enhance boater safety. It
does this in several ways. When working in tandem with a GPS unit, it
helps the Coast Guard respond more quickly to a Distress Call, since
the location of the vessel in distress will be automatically transmitted
when the signal is sent out. It will automatically repeat a distress sig-
nal every four minutes. That would come in handy if, as in the case of a

8
fire, you could not man the radio and fight the fire at the same time.
DSC calling also helps cut back the transmission traffic on Ch. 16, the
emergency priority channel.
How DSC works
A digital selective call uses a digital signal to transmit a pack of in-
formation that can include, the caller’s MMSI number, the MMSI of the
ship or ships being called, call priority and a frequency or mode request.
Location and time of location may be entered manually or if an active
GPS unit is attached, transmitted automatically. DSC calls allow you
to contact a specific ship, a group of ships, a specific group of DSC
receivers, ships in a particular geographic area or all ships within
range of you. A DSC call may even be patched into a regular phone line
through a commercial coastal station. One of the key elements of a DSC
call is the ability to place an individual call directly to another vessel.
Simplex or Duplex
References to simplex and duplex channels are scattered throughout
this manual. Simplex channels transmit and receive messages on the
same frequency. Like a CB radio, only one message can be transmitted
at a time. A duplex channel transmits and receives messages on differ-
ent frequencies. Like a telephone, it gives users the capability to
transmit and receive messages at the same time. You must choose a
simplex channel when making a DSC call!
MMSI (Maritime Mobile Service Identity)
Your Maritime Mobile Service Identity number (MMSI) is like a home
phone number. Other DSC (Digital Selective Calling) radios must enter
your number before they can contact you. But first, you must program
your number into your radio. If your MMSI number is not set up, the ID
ANNUNCIATOR will blink on the display.
CAUTION
You only have one chance to program your MMSI into your ra-
dio. Study this section carefully to ensure the MMSI is entered
correctly.

9
The figure above illustrates the MMSI number entry of 992344513.
If a valid MMSI is already stored in the radio's memory, you will not be
able to enter a MMSI number. If a 9-digit MMSI number has not been
programmed into the radio, you will not be able to make or receive DSC
calls. To enter your assigned MMSI number, follow the steps listed in
the MMSI Setup below.
Warning
Again, there is only one chance to do this procedure correctly,
so go over this section carefully.
MMSI Setup
1. Hold down the CALL key for 5 seconds. The ID ANNUNCIATOR will blink
and a large "0" will be displayed alongside a small “16.” The big num-
ber “0” is the MMSI digit you are entering and the small digit “16” is
the first MMSI character field position. For example, a small digit "2"
represents the 2nd number from the left in your assigned MMSI. If the
number was "4" it would mean the big digit you were entering was the
4th number from the left and so on.
This example gives us a closer look at a number sequence from a MMSI entry.
The big numbers are the MMSI digits. The small numbers in the lower right
hand corner represent the digits' character field position. The big digit 4 is the
sixth number from left in the MMSI. The big digit 5 is seventh from left and
the big digit 1 is eighth from left.

10
NOTE
You need only to modify the big (MMSI) digits. The small digits
(character field position of the MMSI digit) will be generated auto-
matically.
2. Use the Selector to enter the first digit of your MMSI number, then
press the MEM key to advance to the second digit. The small digit now
displays the 2nd character position with a big-digit "0" and small-digit
"2”. Press the Selector to set the second MMSI digit and touch the MEM
key to store. Repeat the operation until all 9 digits have been entered.
After inputting your MMSI, press the MEM key to double-check each
digit.
NOTE
If there is an error in the entry procedure, press the 16/9 key to exit.
You can also turn off the radio to ensure the MMSI won't be stored.
After you are satisfied with the MMSI number you have entered, hold
down the CALL key for 5 seconds to store the number. The ID ANNUCIATOR
will stop blinking and the radio reverts to the main screen. Now you
are ready to make a DSC call.
Choosing a Channel
Before making a call to another vessel, check the VHF chart in the back
of this manual. You'll have to choose a simplex communication channel
authorized for the type of communication you desire.
Making a Call
The MT-300 supports five DSC call types: ALLSHIPS CALL, DIRECTORY CALL,
LAST CALL, NEW CALL and DISTRESS CALL. The example below details a NEW
CALL. For information on the other call types, see page 13.
To place a DSC call
New Call
1. Select a simplex channel and press the CALL key once. LAST blinks.
2. Use the Selector to select NEW CALL.
3. Press the CALL key again. You can now enter the MMSI data of the
vessel you want to contact.
4. Use the Selector to enter the MMSI numbers, pressing MEM after
each digit. After completing MMSI entry, press the MEM key to verify
each number of the MMSI.
5. Press the CALL key and the radio will transmit the request. If there
is no ACK after 4 seconds, the radio transmits the call again. The radio
will stay in standby mode until an ACK is received, indicated by the
flashing ID Annunciator. If an ACK is not received, you can press the
call key again and the call is placed again. You can exit the call func-

11
tion at any time by pressing the 16/9 key twice.
CAUTION
Before transmitting, monitor the selected simplex channel to make
sure it is clear. This is a FCC requirement.
For more in depth information on placing calls see page 13.
To place a non-DSC call:
When making a non-DSC call, you'll have to switch to a communication
channel after making initial contact, so be sure to select a channel au-
thorized for the type of communication you desire.
1. Select an appropriate communication channel.
2. Tune your radio to Ch. 16 or Ch. 9. Speak slowly and clearly, stating
the name of the vessel you are trying to contact followed by "this is
(your ship name and call sign) ."
3. When the other vessel responds, say "go to
(the desired channel
number)
over."
4. Switch to the other working channel. After you are sure it is clear,
call out to the other vessel, stating the vessel's name, followed by "this
is
(your ship name and call sign) ."
Receiving a Call
Reception of an individual call automatically establishes communica-
tion on the working channel requested by the caller. Your radio trans-
mits an ACK (Acknowledgement) message back to the calling radio. If
the calling vessel’s MMSI matches a number stored in your directory,
Ch. 8 is
simplex
working
channel
MMSI Digit Digit number
NEW and ID will blink

12
the number's directory location is shown. If no match is made, the ID
ANNUNCIATOR blinks. If you want to respond to the calling vessel, just
press the PTT button on the microphone. Press the 16/9 key to ignore
the call. See page 18 to get more detailed information on call reception.

13
Section 3: Advanced Operation
This section will give a more detailed explanation of what your radio
can do. We'll start off with a breakdown of the types of DSC calls the
MT-300 can transmit and receive. That will be followed by a brief de-
scription of how to place a non-DSC call. If you are comfortable with
your knowledge regarding transmission and reception of calls, skip
ahead to page 20 to see how to set up a MMSI Directory. On page 27,
there is information on the radio's weather function.
Calls
Transmission
The five DSC calling modes are:
1. AllShips Call:places a call to any ship in range of you.
2. Directory Call: dials number from MMSI directory.
3.
Distress Call: executes an emergency call to Coast Guard and other
ships in range of you.
3. Last Call: dials last incoming call.
4. New Call: places call to caller not in the MMSI directory.
Press CALL then use the Selector to scroll through the four choices (DIS-
TRESS CALL is a separate function, so it is not included in the calls menu).
The LAST CALL option always appears first.
AllShips Call
This feature gives you the option of placing a call to all ships within
range of you.
NOTE
This radio does not handle AllShips urgency or safety DSC calls.
1. Press the CALL key.
2. Use the Selector to select ALLSHIP.
3. Press the CALL key to transmit.
AllShips
calls use
Ch. 6
Four call
sources
to use

14
Directory Call
See page 20 to learn how to setup a MMSI directory. To call a number
from your directory:
1. Use the Selector to select a simplex-working channel.
2. Press the CALL key.
3.Use the Selector to select the call type — DIR, LAST, NEW or ALLSHIPS.
Select DIR, then press CALL.
4. Use Selector to choose a MMSI location number (1-10). The default
number is the MMSI of the last used call.
5. Press the CALL key to transmit. The called radio will acknowledge
and a communication link will be established. Just press PTT to talk.
In the following example, Ch. 8 was used to call a MMSI stored in di-
rectory No. 3.
When the ACK ANNUNCIATOR turns on, the calling channel has been tuned
in and a communication link established. Press PTT to talk.
Distress Call
In an emergency situation, lift the red cover on the front panel to make
a Distress call to the Coast Guard. Press and hold the DISTRESS key for
Choose
directory
mode
Waiting
for ACK
ACK blinks
until PTT is
pressed

15
three seconds. The radio switches to Ch. 16 and a three-second on
screen timer begins to count down in the bottom right corner of the
screen. When it reaches zero, the call is sent out. To stop the call, let go
of the DISTRESS key. No message will be sent unless the timer counts
down to zero. Press the 16/9 key to cancel.
NOTE
If an inadvertent Distress call is sent out, make sure you're on Ch.
16 and quickly transmit a message to all vessels, canceling the Dis-
tress call.
If the DISTRESS key is held down until the timer expires, the radio will
switch to Ch. 70 and a distress call will be sent out. The DSC Distress
message is transmitted at 25 watts.
The Distress message contains your MMSI, your position and the UTC
time acquired from your GPS, if you're using a GPS unit. The DISTRESS
ANNUNCIATOR is displayed during the transmission.
A loud 2-tone alarm sounds. This alarm cannot be stopped unless the
mode is canceled. Pressing the 16/9 or PTT key cancels the DISTRESS WAIT-
ING MODE. If the mode is not canceled, the radio transmits the Distress
message again every 4 minutes. A DISTRESS WAIT message will be dis-
played on the screen.
NOTE
The Coast Guard is the only agency allowed to acknowledge a Dis-
tress call. An individual vessel's DSC radio will not automatically
respond with an acknowledgement.
3-second
timer
Distress
Message
being sent Timer
expired