Icom IC-M423 User manual

INSTRUCTION MANUAL
VHF MARINE TRANSCEIVER
This device complies with Part 15 of the FCC
Rules. Operation is subject to the condition that
this device does not cause harmful interference.
iM423
iM423G
iM424
iM424G
IC-M423G

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FOREWORD
Thank you for choosing this Icom product. The IC-M423/IC-
M423G/IC-M424/IC-M424G v h f m a r i n e t r a n s c e i v e r is de-
signed and built with Icom’s state of the art technology and
craftsmanship. With proper care, this product should provide
you with years of trouble-free operation.
Hope you agree with Icom’s philosophy of “technology first.”
Many hours of research and development went into the de-
sign of your radio.
FEATURESD
❍Simple operation with large keys
❍Easy to hear speaker
❍Built-in DSC meets ITU Class D requirement
❍Rugged waterproof construction
❍Optional COMMANDMIC
IV ™ (HM-195)
❍Easy to make an individual DSC calls using the
optional MA-500TR Class B AIS Transponder
❍Built-in GPS *
*For only IC-M423G and IC-M424G.
IMPORTANT
READ ALL INSTRUCTIONS carefully and completely
before using the transceiver.
SAVE THIS INSTRUCTION MANUAL — This in-
struction manual contains important operating instructions
for the transceiver.
EXPLICIT DEFINITIONS
WORD DEFINITION
RWARNING! Personal injury, fire hazard or electric
shock may occur.
CAUTION Equipment damage may occur.
NOTE
If disregarded, inconvenience only. No risk
of personal injury, fire or electric shock.
CLEAN THE TRANSCEIVER AND MICROPHONE THOR-
OUGHLY WITH FRESH WATER after exposure to water
including salt, otherwise, the keys and switch may become
inoperable due to salt crystallization.

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IN CASE OF EMERGENCY
If your vessel requires assistance, contact other vessels and
the Coast Guard by sending a Distress call on Channel 16.
Or, make your Distress call using digital selective calling on
Channel 70.
USING CHANNEL 16
DISTRESS CALL PROCEDURE
1. “MAYDAY MAYDAY MAYDAY.”
2. “THIS IS ...............” (name of vessel).
3. Say your call sign or other description of the vessel (AND
9 digit DSC ID if you have one).
4. “LOCATED AT ...............” (your position).
5. State the nature of the distress and assistance required.
6. Give any other information which might facilitate the res-
cue.
USING DIGITAL SELECTIVE CALLING (Ch 70)
DISTRESS CALL PROCEDURE
1. While lifting up the key cover, hold down [DISTRESS]
for 3 seconds until you hear 3 short beeps and then one
long beep.
2. Wait for an acknowledgment on Channel 70 from a coast
station.
 •Aftertheacknowledgementisreceived,Channel16isauto-
matically selected.
3. Hold down [PTT], then transmit the appropriate informa-
tion as listed above.
COUNTRY CODE LIST
• ISO 3166-1
Country Codes Country Codes
1Austria AT 18 Liechtenstein LI
2Belgium BE 19 Lithuania LT
3Bulgaria BG 20 Luxembourg LU
4Croatia HR 21 Malta MT
5 Czech Republic CZ 22 Netherlands NL
6Cyprus CY 23 Norway NO
7 Denmark DK 24 Poland PL
8 Estonia EE 25 Portugal PT
9 Finland FI 26 Romania RO
10 France FR 27 Slovakia SK
11 Germany DE 28 Slovenia SI
12 Greece GR 29 Spain ES
13 Hungary HU 30 Sweden SE
14 Iceland IS 31 Switzerland CH
15 Ireland IE 32 Turkey TR
16 Italy IT 3 3 United Kingdom GB
17 Latvia LV
Icom, Icom Inc. and the Icom logo are registered trademarks of Icom Incor-
porated (Japan) in Japan, the United States, the United Kingdom, Germany,
France, Spain, Russia, and/or other countries.
COMMANDMIC is a registered trademark of Icom Incorporated (Japan) in Ja-
pan and the United States.

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RADIO OPERATOR WARNING
WARNING
Icom requires the radio operator to meet the
FCC Requirements for Radio Frequency Expo-
sure. An omnidirectional antenna with gain not
greater than 9 dBi must be mounted a mini-
mum of 5 meters (measured from the lowest
point of the antenna) vertically above the main
deck and all possible personnel. This is the minimum safe
separation distance estimated to meet all RF exposure com-
pliance requirements. This 5 meter distance is based on the
FCC Safe Maximum Permissible Exposure (MPE) distance
of 3 meters added to the height of an adult (2 meters) and is
appropriate for all vessels.
For watercraft without suitable structures, the antenna must
be mounted so as to maintain a minimum of 1 meter verti-
cally between the antenna, (measured from the lowest point
of the antenna), to the heads of all persons AND all persons
must stay outside of the 3 meter MPE radius.
Do not transmit with radio and antenna when persons are
within the MPE radius of the antenna, unless such persons
(such as driver or radio operator) are shielded from antenna
field by a grounded metallic barrier. The MPE Radius is the
minimum distance from the antenna axis that person should
maintain in order to avoid RF exposure higher than the al-
lowable MPE level set by FCC.
FAILURE TO OBSERVE THESE LIMITS MAY ALLOW
THOSE WITHIN THE MPE RADIUS TO EXPERIENCE RF
RADIATION ABSORPTION WHICH EXCEEDS THE FCC
MAXIMUM PERMISSIBLE EXPOSURE (MPE) LIMIT.
IT IS THE RESPONSIBILITY OF THE RADIO OPERATOR
TO ENSURE THAT THE MAXIMUM PERMISSIBLE EXPO-
SURE LIMITS ARE OBSERVED AT ALL TIMES DURING
RADIO TRANSMISSION. THE RADIO OPERATOR IS TO
ENSURE THAT NO BYSTANDERS COME WITHIN THE
RADIUS OF THE MAXIMUM PERMISSIBLE EXPOSURE
LIMITS.
Determining MPE Radius
THE MAXIMUM PERMISSIBLE EXPOSURE (MPE) RA-
DIUS HAS BEEN ESTIMATED TO BE A RADIUS OF
ABOUT 3M PER OET BULLETIN 65 OF THE FCC.
THIS ESTIMATE IS MADE ASSUMING THE MAXIMUM
POWER OF THE RADIO AND ANTENNAS WITH A MAXI-
MUM GAIN OF 9dBi ARE USED FOR A SHIP MOUNTED
SYSTEM.

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AVERTISSEMENT POUR LES OPÉRATEURS RADIO
Icom exige que l'opérateur radio se conforme aux
exigences de la FCC en matière d'exposition aux
radiofréquences. Une antenne omnidirectionnelle
dont le gain ne dépasse pas 9dBi doit être fixée
à une distance minimale de 5 mètres (mesurée
depuis le point le plus bas de l'antenne) verticale-
ment au-dessus du pont principal et de tout le personnel qui peut
s'y trouver. Il s'agit de la distance de sécurité minimale prévue pour
satisfaire aux exigences de conformité en matière d'exposition aux
RF. Cette distance de 5 mètres est établie en fonction de l'exposition
maximale admissible sécuritaire de 3 mètres établie par la FCC, à
laquelle on ajoute la hauteur d'un adulte (2 mètres); cette distance
convient pour tous les navires.
Dans le cas des embarcations sans structure convenable, l'antenne
doit être fixée de façon à maintenir une distance minimale de 1 mètre
verticalement entre cette antenne (mesurée depuis son point le plus
bas) et la tête de toute personne présente; toutes les personnes
présentes doivent se tenir à l'extérieur d'un rayon d'exposition maxi-
male admissible de 3 mètres.
Ne pas émettre à l'aide de la radio et de l'antenne lorsque des
personnes se trouvent à l'intérieur du rayon d'exposition maximale
admissible de cette antenne, à moins que ces personnes (comme
le conducteur ou l'opérateur radio) ne soient protégées du champ
de l'antenne par un écran métallique relié à la masse. Le rayon
d'exposition maximale admissible équivaut à la distance minimale
que cette personne doit maintenir entre elle et l'axe de l'antenne pour
éviter une exposition aux RF supérieure au niveau d'exposition maxi-
male admissible fixé par la FCC.
LE NON-RESPECT DE CES LIMITES PEUT CAUSER, POUR LES
PERSONNES SITUÉES DANS LE RAYON D'EXPOSITION MAXI-
MALE ADMISSIBLE, UNE ABSORPTION DE RAYONNEMENT DE
RF SUPÉRIEURE À L'EXPOSITION MAXIMALE ADMISSIBLE
FIXÉE PAR LA FCC.
L'OPÉRATEUR RADIO EST RESPONSABLE D'ASSURER QUE
LES LIMITES D'EXPOSITION MAXIMALE ADMISSIBLE SOIENT
RESPECTÉES EN TOUT TEMPS PENDANT LA TRANSMISSION
RADIO. L'OPÉRATEUR RADIO DOIT S'ASSURER QU'AUCUNE
PERSONNE PRÉSENTE NE SE SITUE À L'INTÉRIEUR DU RAY-
ON D'EXPOSITION MAXIMALE ADMISSIBLE.
Établir le rayon d'exposition maximale admissible
ON ESTIME QUE LE RAYON D'EXPOSITION MAXIMALE ADMIS-
SIBLE EST D'ENVIRON 3 M, TEL QUE STIPULÉ DANS LE BUL-
LETIN OET 65 DE LA FCC. CETTE DISTANCE ESTIMÉE TIENT
COMPTE D'UN SYSTÈME INSTALLÉ SUR UN NAVIRE UTILISANT
LA PUISSANCE MAXIMALE DE LA RADIO ET DES ANTENNES
DONT LE GAIN MAXIMAL EST DE 9dBi.
AVERTISSEMENT

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FCC INFORMATION
• FOR CLASS A UNINTENTIONAL RADIATORS:
This equipment has been tested and found to comply with the
limits for a Class A digital device, pursuant to part 15 of the
FCC Rules. These limits are designed to provide reasonable
protection against harmful interference when the equipment
is operated in a commercial environment. This equipment
generates, uses, and can radiate radio frequency energy
and, if not installed and used in accordance with the instruc-
tion manual, may cause harmful interference to radio com-
munications.
Operation of this equipment in a residential area is likely to
cause harmful interference in which case the user will be re-
quired to correct the interference at his own expense.
• POUR LES RAYONNEMENTS NON INTENTIONNELS DE
CLASSE A:
Cet équipement a été testé et reconnu conforme aux limites fixées
pour un appareil numérique de classe A, conformément au point
15 de la réglementation FCC. Ces limites sont définies de façon à
fournir une protection raisonnable contre le brouillage préjudiciable
lorsque cet appareil est utilisé dans un environnement commercial.
Cet équipement génère, utilise et peut émettre un rayonnement de
fréquence radio. S'il n'a pas été installé conformément aux instruc-
tions, il peut par ailleurs créer des interférences perturbant les com-
munications radio.
L'utilisation de cet appareil dans une zone résidentielle peut provo-
quer un brouillage préjudiciable, auquel cas l'utilisateur sera tenu de
corriger la situation à ses frais.
NOTE
A WARNING STICKER is supplied with the U.S.A. version
transceiver.
To comply with FCC regulations, this sticker must be affixed in
such a location as to be readily seen from the operating con-
trols of the radio as in the diagram below. Make sure the chosen
location is clean and dry before applying the sticker.
EXAMPLE
WARNING.

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New2001
PRECAUTIONS
RWARNING! NEVER connect the transceiver to an AC
outlet. This may pose a fire hazard or result in an electric shock.
RWARNING! NEVER connect the transceiver to a pow-
er source of more than 16 V DC such as a 24 V DC. This
could cause a fire or damage the transceiver.
RWARNING! NEVER reverse the DC power cable po-
larity when connecting to a power source.This could damage
the transceiver.
RWARNING! NEVER cut the DC power cable between
the DC plug at the back of the transceiver and fuse holder. If
an incorrect connection is made after cutting, the transceiver
may be damaged.
CAUTION: NEVER place the transceiver where normal
operation of the vessel may be hindered or where it could
cause bodily injury.
KEEP the transceiver and microphone at least 1 m away
from the vessel’s magnetic navigation compass.
DO NOT use or place the transceiver in areas with tem-
peratures below –20°C (–4°F) or above +60°C (+140°F) or, in
areas subject to direct sunlight, such as the dashboard.
DO NOT use harsh solvents such as benzine or alcohol to
clean the transceiver, as they will damage the transceiver’s
surfaces. If the transceiver becomes dusty or dirty, wipe it
clean with a soft, dry cloth.
DO NOT disassemble or modify the transceiver for any rea-
son.
BE CAREFUL! The transceiver rear panel will become
hot when operating continuously for long periods of time.
Place the transceiver in a secure place to avoid inadvertent
use by children.
BE CAREFUL! The transceiver and the optional HM-195
c o m m a n d m i c IV™meet IPX7 requirements for waterproof
protection. However, once the transceiver has been dropped,
waterproof protection cannot be guaranteed because of pos-
sible damage to the transceiver’s case or the waterproof
seal.
* Except for the DC power connector, NMEA In/Out leads, and AF
Out leads.
For U.S.A. only
CAUTION: Changes or modifications to this device, not ex-
pressly approved by Icom Inc., could void your authority to
operate this device under FCC regulations.

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New2001
PRÉCAUTIONS
RAVERTISSEMENT! NE JAMAIS connecter l’emetteur-
recepteur a une alimentation CA au risque de provoquer un in-
cendie ou un choc electrique.
R AVERTISSEMENT! NE JAMAIS brancher l'émetteur-
récepteur à une source d'alimentation de plus de 16 V CC,
comme une source de 24 V CC. Cela pourrait causer un in-
cendie ou endommager l'émetteur-récepteur.
R AVERTISSEMENT! NE JAMAIS inverser la po-
larité du câble d'alimentation CC en le branchant à la source
d'alimentation. Cela pourrait endommager l'émetteur-récepteur.
R AVERTISSEMENT! NE JAMAIS sectionner le câble
d'alimentation CC entre la prise CC de la face arrière de
l'émetteur-récepteur et le porte-fusible. L’émetteur-récepteur
peut être endommagé par la suite en cas de connexion inap-
propriée.
MISE EN GARDE: NE JAMAIS installer l’émetteur-
récepteur à un emplacement où il pourrait gêner le fonction-
nement normal du navire ou provoquer des blessures cor-
porelles.
MAINTENIR l'émetteur-récepteur et le microphone à au
moins 1 mètre du compas de route magnétique du navire.
NE PAS utiliser ou placer l’émetteur-récepteur dans des
zones où la temperature est inférieure à –20° (–4°F) ou
supérieure à +60° (+140°F) ou dans des zones soumises
au rayonnement solaire direct, telles le tableau de bord.
NE PAS nettoyer l'appareil avec des solvants agressifs tels
que benzène ou alcool, susceptibles d'endommager les sur-
faces exposées du boîtier. En cas de dépôt de poussière ou
de salissures sur l'émetteur-récepteur, il faut l'essuyer avec
chiffon doux et sec.
NE PAS démonter ou modifier l'émetteur-récepteur pour
quelque raison que ce soit.
ATTENTION! La face arrière de l’émetteur-récepteur
chauffe en cas d’utilisation continue sur une longue durée.
Placer l’émetteur-récepteur hors de portée des enfants pour
éviter toute utilisation inopinée.
ATTENTION! L'émetteur-récepteur et l'accessoire option-
nel c o m m a n d m i c IVmc répondent aux exigences de l'indice
d'étanchéité IPX7*. Cependant, cette etancheite n’est plus
garantie apres une chute de l’appareil en raison des fissures
du boitier ou des dommages au joint d’etancheite et autres
dommages eventuels consecutifs a un tel incident.
* À l'exception du connecteur d'alimentation CC, des fils d'entrée ou
de sortie NMEA et des fils de sortie de fréquences audio.

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New2001
TABLE OF CONTENTS
FOREWORD .........................................................................i
IMPORTANT.......................................................................... i
EXPLICIT DEFINITIONS....................................................... i
COUNTRY CODE LIST........................................................ ii
IN CASE OF EMERGENCY................................................. ii
RADIO OPERATOR WARNING .......................................... iii
AVERTISSEMENT POUR LES OPÉRATEURS RADIO...... iv
FCC INFORMATION ............................................................ v
NOTE....................................................................................v
PRECAUTIONS................................................................... vi
PRÉCAUTIONS.................................................................. vii
TABLE OF CONTENTS......................................................viii
TABLE OF CONTENTS (continued).................................... ix
1 OPERATING RULES.......................................................1
2 PANEL DESCRIPTION....................................................2
Front panel■...................................................................2
Function display■...........................................................5
Softkey function■............................................................7
Speaker Microphone■....................................................8
3 PREPARATION................................................................9
Entering the MMSI code■..............................................9
Entering the ATIS code■
(For Dutch and German version transceivers) ...........10
4 BASIC OPERATION......................................................11
Selecting a Channel■...................................................11
Receiving and transmitting■.........................................14
Adjusting the■volume and squelch levels ...................15
Entering a Call channel data■......................................16
Entering a Channel name■..........................................16
Microphone Lock function■..........................................17
Adjusting the Backlight level■.......................................18
Using the AquaQuake water draining function■...........18
5 SCAN OPERATION.......................................................19
Scan types■.................................................................19
Setting Favorite channels■...........................................20
Starting a scan■...........................................................20
6 DUALWATCH/TRI-WATCH............................................21
Description■.................................................................21
Operation■...................................................................21
7 DSC OPERATION .........................................................22
DSC address ID■........................................................22
Entering position and time■.........................................25
Making a Distress call■................................................26
Making DSC calls■.......................................................30
Receiving DSC calls■..................................................53
Transmitted Call log■....................................................60
Received Call log■.......................................................61

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TABLE OF CONTENTS (continued)
DSC Settings■.............................................................63
Making an Individual call using an AIS transponder■..67
8 OTHER FUNCTIONS.....................................................69
Using the Intercom■.....................................................69
Using the RX Speaker■................................................70
Using the PA (Public A■ddress) ...................................70
Using the Horn■...........................................................71
9 MENU SCREEN OPERATION ......................................72
Using the Menu screen■..............................................72
Menu screen items■.....................................................73
Radio Settings items■..................................................74
Configuration items■....................................................76
10 CONNECTIONS AND MAINTENANCE ........................82
Connections■...............................................................82
Antenna■......................................................................84
Fuse replacement■......................................................84
Cleaning■.....................................................................84
Supplied accessories■.................................................84
Mounting the transceiver■............................................85
MB-132 installation■....................................................86
Microphone installation■..............................................87
11 SPECIFICATIONS AND OPTIONS ...............................89
Specifications■.............................................................89
Options■.......................................................................90
12 CHANNEL LIST.............................................................91
13 TROUBLESHOOTING...................................................92
14 TEMPLATE....................................................................93
INDEX.................................................................................95

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OPERATING RULES
PrioritiesD
•Readall rules and regulationspertaining to call priorities,
and keep an up-to-date copy handy. Safety and distress
calls take priority over all others.
•YoumustmonitorChannel16whenyouarenotoperating
on another channel.
•Falseorfraudulentdistresscallsareprohibitedunderlaw.
PrivacyD
•Informationoverheard,butnotintendedforyou,cannotlaw-
fully be used in any way.
•Indecentorprofanelanguageisprohibited.
Radio licensesD
(1) SHIP STATION LICENSE
You may require a current radio station license before using
the transceiver. It is unlawful to operate a ship station which is
not licensed, but required to be.
If required, contact your dealer or the appropriate govern-
ment agency for a Ship-Radiotelephone license application.
This government-issued license states the call sign which is
your craft’s identification for radio purposes.
(2) OPERATOR’S LICENSE
A Restricted Radiotelephone Operator Permit is the license
most often held by small vessel radio operators when a radio
is not required for safety purposes.
If required, the Restricted Radiotelephone Operator Permit
must be posted or kept with the operator. If required, only a
licensed radio operator may operate a transceiver.
However, non-licensed individuals may talk over a transceiver
if a licensed operator starts, supervises, ends the call and
makes the necessary log entries.
A current copy of the applicable government rules and regu-
lations is only required to be on hand for vessels in which
a radio telephone is compulsory. However, even if you are
not required to have these on hand it is your responsibility to
be thoroughly acquainted with all pertinent rules and regula-
tions.
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PANEL DESCRIPTION
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■Front panel
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qFunction display (p. 5)Speaker
qDISTRESS KEY [DISTRESS] (pp. 26, 27)
Hold down for 3 seconds to make a Distress call.
wENTER KEY [ENT] (pp. 9, 12, 72)
Push to set the entered data, selected item, and so on.
eLEFT AND RIGHT KEYS [Ω]/[≈]
Push to change to the previous or next key function that➥
is assigned to the softkeys. (p. 7)
Push to select the desired character or number in the➥
table while in the channel name, position, MMSI code
entry mode, and so on. (pp. 9, 16, 25)
r
UP AND DOWN/CHANNEL SELECT KEYS [∫•CH]/[√•CH]
Push to select the operating channels, Menu items,➥
Menu settings, and so on. (pp. 14, 72)
While scanning, push to check Favorite channels,➥
change the scanning direction or manually resume a
scan. (p. 20)
tCLEAR KEY [CLEAR]
(pp. 9 , 16 , 72 )
Push to cancel the entered data, or to return to the previ-
ous screen.
yMENU KEY [MENU]
(p. 72 )
Push to enter or exit the Menu screen.
uVOLUME AND SQUELCH SWITCH/POWER SWITCH
[VOL/SQL•PWR]
When the power is OFF, hold down for 1 second to turn➥
ON power. (p. 14)
Hold down for 1 second to turn OFF power.➥
When the power is ON, push to enter the volume level➥
adjustment mode.* (p. 15)
  •Eachpushofthisswitchtogglesthemodebetweenthevol-
ume level adjustment, squelch threshold level adjustment,
operating channel selection, and the LCD and key backlight
brightness adjustment, if assigned.
Rotate to adjust the volume level.* (p. 15)➥
*The desired function can be assigned in the Menu screen.

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PANEL DESCRIPTION
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i CHANNEL 16/CALL CHANNEL KEY [16/C]
Push to select Channel 16. (p. 11)➥
Hold down for 1 second to select the Call channel. (p.➥
11 )
  •“CALL”isdisplayedwhentheCallchannelisselected.
➥ When the Call channel is selected, hold down for 3 sec-
onds to enter Call channel entry mode. (p.
16 )
oSOFTKEYS
Desired functions as described below can be assigned in
the Menu screen.
Scan [ ](p. 20)
Push to start or stop a Normal or Priority scan.
Dualwatch/Tri-watch [ ](p. 21)
Push to start Dualwatch or Tri-watch.➥
Push to stop Dualwatch or Tri-watch when either is ac-➥
tivated.
High/Low [ ](p. 14)
Push to set the power to high or low.
 •Somechannelsaresettoonlylowpower.
Channel/Weather channel [ ]* (pp. 11, 13)
Push to selects and toggles the regular channel and
Weather channel.
*For only U.S.A. and Australian version transceivers.
Channel [ ]* (p. 11)
Push to select a regular channel.
* For only IC-M423 and IC-M423G except for Australian version
transceivers.
Public address [ ] (p. 70)
Push to enter the PA (Public Address) mode.
RX Speaker [ ](p. 70)
Push to turn the RX Speaker mode ON or OFF.
Horn [ ](p. 71)
Push to enter the Horn mode.
Intercom [ ](p. 69)
Push to enter the Intercom mode.
LO/DX [ ]* (p. 14)
Push to turn the Attenuator function ON or OFF.
 •“LOCAL”isdisplayedwhentheAttenuatorfunctionisON.
*For only U.S.A. and Australian version transceivers.
AquaQuake [ ] (p. 18)
Holding down to activate the AquaQuake to clear water
away from the speaker grill.

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2PANEL DESCRIPTION
New2001
■Front panel (Continued)
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qFunction display (p. 5)Speaker
Favorite channel [ ] (p. 20)
Push to set or clear the displayed channel as a Favorite➥
(Tag) channel.
Hold down for 3 seconds to clear or set all Favorite➥
channels in the selected channel group.
Name [ ](p. 16)
Push to enter the channel name entry mode.
Backlight [ ] (p. 18)
Push to enter the LCD and key backlight brightness ad-
justment mode.
 •Whileintheadjustmentmode,push[∫]/[√]/[Ω]/[≈] or rotate Dial
to adjust the brightness of the LCD and key backlight.
Log [ ] (p. 61)
Push to enter “RCVD CALL LOG” in the DSC CALLS menu.

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PANEL DESCRIPTION
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■Function display
!8
!4
!6
!7
!5
qw ietr!0you
!1
!2
!3
qBUSY/TRANSMIT ICON (p. 14)
“➥” is displayed when receiving a signal or when
the squelch is open.
“➥” is displayed while transmitting.
wPOWER ICON (p. 14)
“25W” is displayed when high power is selected.➥
“1W” is displayed when low power is selected.➥
eRX SPEAKER ICON (p. 70)
Displayed while in the RX Speaker mode.
rCHANNEL GROUP ICON (p. 12)
Shows which channel group is selected, INT, USA,➥
CAN, ATIS or DSC, depending on the version.
“WX” is displayed when the weather channel is select-➥
ed.*
*For only U.S.A. and Australian version transceivers.
tCALL CHANNEL ICON (p. 11)
Displayed when the Call channel is selected.
yDUPLEX ICON (p. 12)
Displayed when a duplex channel is selected.
uFAVORITE CHANNEL ICON (p. 20)
Displayed when a Favorite (Tag) channel is selected.
iMESSAGE ICON (p. 61)
Blinks when there is an unread DSC message.
oGPS ICON
Stays ON when the built-in GPS receiver* or an exter-➥
nal GPS receiver is receiving valid position data.
*For only IC-M423G and IC-M424G.
Blinks when searching for valid position data.➥
!0 SWITCH ICON (p. 64)
Displayed when the “CH 16 SWITCH” in DSC Settings is
set to OFF.

6
2PANEL DESCRIPTION
■Function display (Continued)
!8
!4
!6
!7
!5
qw ietr!0you
!1
!2
!3
!1 LOW BATTERY ICON
Blinks when the battery voltage drops to approximately
10 V DC or less.
!2 CHANNEL NUMBER READOUT
Shows the selected operating channel number.
 •Whenasimplexchannelisselected,“A”isdisplayed.
!3 CHANNEL NAME FIELD
The channel name is displayed, if entered. (p. 16)
!4 KEY ICON (p. 7)
Shows the preset function of the softkeys on the front pan-
el.
!5 TIME ZONE INDICATOR
Shows the current time when GPS data is received, or➥
the time is manually entered.
  •When the GPS current time is invalid, “??” will blink every
2 seconds instead of the current time. After 23.5 hours has
passed, “NO TIME” is displayed.
  •“??” will blink every 2 seconds instead of the current time,
after 4 hours have passed from when the time was manu-
ally entered. The manually entered time is held for only 23.5
hours, and after that, “NO TIME” is displayed.
“LOCAL”➥ is displayed when the offset time is set.
“MNL”➥
is displayed when the time is manually entered .
“UTC”➥
is displayed when the GGA, GLL or GNS GPS
sentence format is included in the GPS signal.
The date information➥ is displayed when the RMC GPS
sentence format is included in the GPS signal.
“NO TIME”➥
is displayed when no GPS receiver is con-
nected, and no time is manually entered.
NOTE for the IC-M423 and IC-M424:
These models do not come with a built-in GPS receiver.
Therefore an external GPS receiver needs to be con-
nected, or the time needs to be manually entered for
the time zone indicator to be displayed.

7
2
PANEL DESCRIPTION
New2001
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
!6 POSITION INDICATOR
➥ Shows the current position when position data is re-
ceived, or the position is manually entered.
  •WhentheGPSpositionisinvalid,“??”mayblinkevery2sec-
onds instead of position. The last position is held for only
23.5 hours, and after that, “NO POSITION” is displayed.
  • “??”willblinkevery2secondsinsteadofposition,after4hours
have passed from the time when the position is manually en-
tered.The manually entered position is held for only 23.5 hours,
and after that, “NO POSITION” is displayed.
➥ “NO POSITION” is displayed when no GPS receiver is
connected, and no position is manually input.
!7 SCAN INDICATOR
“SCAN 16” is displayed during a Priority scan; “SCAN”➥
is displayed during a Normal scan. (p. 20)
“DUAL 16” is displayed during Dualwatch; “TRI 16” is➥
displayed during Tri-watch. (p. 20)
!8 LOCAL ICON* (p. 14)
Displayed when the Attenuator function is turned ON.
*For only U.S.A. and Australian version transceivers.
■Softkey function
Various functions can be assigned to the softkeys. When a
key function is assigned, the key icon is displayed above the
softkey, as shown below.
Softkey function selectionD
When “Ω” or “≈” is displayed beside the key icon, sequentially
pushing [Ω]/[≈] displays the previous or the next key function
that is assigned to the softkey.
Push Push
*
*Push this key to start
and stop scan.
The order of the key icons may differ, depending on the
presetting.

8
2PANEL DESCRIPTION
New2001 New2001
Speaker Microphone■
Microphone
Speaker
IC-M423G/IC-M424G IC-M423/IC-M424
w
q
e
r
qPTT [PTT]
Hold down to transmit, release to receive. (p. 14)
wCHANNEL UP/DOWN KEYS [Y]/[Z]
Push either key to check Favorite channels, change scan-
ning direction or manually resumes a scan. (pp. 14, 20)
eTRANSMIT POWER KEY [H/L]*
Push to toggle the power high or low. (p. 14)➥
  •Somechannelsaresettoonlylowpower.
While holding down [H/L], turn ON the power to turn the➥
Microphone Lock function ON or OFF. (p. 17)
*[HI/LO] is printed for the IC-M423/IC-M424.
r CHANNEL 16/CALL CHANNEL KEY [16/C]
➥Push to select Channel 16. (p. 11)
➥Hold down for 1 second to select the Call channel. (p.
11 )
  •The“CALL” icon is displayed when the Call channel is se-
lected.
*For only IC-M423G and IC-M424G.

9
3
PREPARATION
New2001
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Entering the■MMSI code
The 9 digit MMSI (Maritime Mobile Service Identity: DSC self
ID) code can be entered at power ON.
This initial code setting can be made only once.
After being set, it can be changed by only your dealer
or distributor. If your MMSI code has already been en-
tered, the following steps are not necessary.
Hold down [PWR](Dial) to turn ON the power.q
 •Threeshortbeepssound,and“NODSCMMSI”isdisplayed.
Push [ENT] to start the MMSI code entry.w
 •Push[CLEAR]twicetocanceltheentry,andgotothenormal
operating screen. In this case, the transceiver cannot make a
DSC call.To enter the MMSI code, turn OFF the power, then turn
it ON again.
Enter your MMSI code in the following way:e
 •SelectadesirednumberusingDial,or[∫]/[√]/[Ω]/[≈].
 •Push[ENT]orDialtosetit.
 •Tomovethecursor,selecteitherarrow,“←” or “→,” then push
[ENT] or Dial.
Repeat stepr e to enter all 9 digits.
After entering the 9 digit code, “FINISH” is automaticallyt
selected, and then push [ENT] or Dial to set it.
The “MMSI CONFIRMATION” screen is displayed.y
Enter your MMSI code again for confirmation.u
 •Enterinthesamewayasstepsethrough t.
When your MMSI code entry is successfully completed,i
the screen as shown below is briefly displayed.
 •Afterthat,thenormaloperatingscreenisdisplayed.
The entered MMSI code can be checked in the MENU screen.
(p. 72)
NOTE: Depending on the transceiver version, the ATIS
code entry may be required after entering the MMSI code.
See the next page for details.

10
3PREPARATION
New2001 New2001
The 10 digit ATIS (Automatic Transmitter Identification Sys-
tem) code can be entered at power ON.
This initial code setting can be made only once.
After being set, it can be changed by only your dealer
or distributor. If your ATIS code has already been en-
tered, the following steps are not necessary.
After entered the MMSI code, “Push [ENT] to Registerq
Your ATIS” is displayed.
Push [ENT] to start entering the ATIS code.w
 •Push[CLEAR]twicetocanceltheentry,andgotothenormal
operating mode. In this case, the ATIS function is disabled. To
enter the ATIS code, turn OFF the power, then turn it ON again.
Enter your ATIS code in the following manner:e
 •SelectadesirednumberusingDial,or[∫]/[√]/[Ω]/[≈].
 •Push[ENT]orDialtosetit.
 •Tomovethecursor,selecteitherarrow,“←” or “→,” then push
[ENT] or Dial.
Repeat stepr e to enter all 10 digits.
After entering the 10 digit code, “FINISH” is automaticallyt
selected, and then push [ENT] or Dial to set it.
The “ATIS CONFIRMATION” screen is displayed.y
Enter your ATIS code again for confirmation.u
 •Enterinthesamemannerasstepsethrough t.
When your ATIS code is successfully entered, the screeni
as shown below is briefly displayed.
 •Afterthat,thenormaloperatingscreenisdisplayed.
The entered ATIS code can be checked in the MENU screen.
(p. 72)
Entering the■ATIS code (For Dutch and German version transceivers)