Page 2 - FOREWORD; FEATURES; IMPORTANT; READ ALL INSTRUCTIONS; EXPLICIT DEFINITIONS
i FOREWORD Thank you for purchasing this Icom radio. The IC-M304 VHF MARINE TRANSCEIVER is designed and built with Icom’s state of the art technology and craftsmanship. With proper care,this radio should provide you with years of trouble-free oper-ation. We hope you agree with Icom’s philosophy of “...
Page 3 - USING DIGITAL SELECTIVE CALLING; USING CHANNEL 16; DISTRESS CALL PROCEDURE
ii IN CASE OF EMERGENCY If your vessel requires assistance, contact other vessels andthe Coast Guard by sending a distress call on Channel 16. Or, transmit your distress call using digital selective calling onChannel 70. NOTE A WARNING STICKER is supplied with the transceiver. To comply with FCC reg...
Page 4 - RADIO OPERATOR WARNING
iii RADIO OPERATOR WARNING Icom requires the radio operator to meet theFCC Requirements for Radio Frequency Expo-sure. An omnidirectional antenna with gain notgreater than 9 dBi must be mounted a minimumof 5 meters (measured from the lowest point ofthe antenna) vertically above the main deck and all...
Page 5 - TABLE OF CONTENTS
iv FOREWORD …………………………………………………………… iIMPORTANT …………………………………………………………… iEXPLICIT DEFINITIONS ……………………………………………… iIN CASE OF EMERGENCY…………………………………………… iiNOTE …………………………………………………………………… iiRADIO OPERATOR WARNING ……………………………………… iiiTABLE OF CONTENTS ……………………………………………… ivPRECAUTIONS ……………………………………………………...
Page 6 - PRECAUTIONS
v PRECAUTIONS R WARNING! NEVER connect the transceiver to an AC outlet. This may pose a fire hazard or result in an electricshock. CAUTION: Changes or modifications to this device, not ex- pressly approved by Icom Inc., could void your authority tooperate this device under FCC regulations. NEVER con...
Page 7 - OPERATING RULES; PRIORITIES
1 1 OPERATING RULES D D PRIORITIES • Read all rules and regulations pertaining to priorities and keep an up-to-date copy handy. Safety and distress callstake priority over all others. • You must monitor Channel 16 when you are not operating on another channel. • False or fraudulent distress signals ...
Page 8 - PANEL DESCRIPTION; Front panel
2 PANEL DESCRIPTION 2 ■ Front panel q CHANNEL UP/DOWN KEYS [ Y Y ]/[ Z Z ]•[U/I/C] ➥ Selects the operating channels, Set mode settings, etc.(pgs. 5, 6, 28) ➥ While pushing and holding [SCAN] , push to adjust the brightness of the LCD and key backlight. (p. 9) ➥ Selects one of three channel groups in...
Page 10 - Function display
4 2 PANEL DESCRIPTION ■ Function display q CHANNEL GROUP INDICATOR (p. 6) Indicates whether a U.S.A. “ U ,” International “ ” or Cana- dian “ C ” channel is in use. w CHANNEL NUMBER READOUT ➥ Indicates the selected operating channel number. • Refer to CHANNEL LIST . (p. 36) ➥ In Set mode, indicates ...
Page 11 - BASIC OPERATION; Channel selection
5 3 BASIC OPERATION 2 3 ■ Channel selection ï ï Channel 16 Channel 16 is the distress and safety channel. It is used forestablishing initial contact with a station and for emergencycommunications. Channel 16 is monitored during both Dual-watch and Tri-watch. While standing by, you must monitorChanne...
Page 12 - Weather channels
6 3 BASIC OPERATION ï ï U.S.A.,Canadian and international channels The IC-M304 is pre-programmed with 59 U.S.A., 59 interna-tional and 63 Canadian channels. These channel groups maybe specified for the operating area. q Push [CH/WX] to select a regular channel. • If a weather channel appears, push [...
Page 13 - Receiving and transmitting
7 3 BASIC OPERATION 3 ■ Receiving and transmitting CAUTION: Transmitting without an antenna will damage the transceiver. q Rotate [VOL] to turn power ON. w Set the audio and squelch levels. ➥ Rotate [SQL] fully counterclockwise in advance. ➥ Rotate [VOL] to adjust the audio output level. ➥ Rotate [S...
Page 14 - Call channel programming; Channel comments
8 3 BASIC OPERATION ■ Call channel programming Call channel is used to select Channel 9 (default), however,you can program the call channel with your most often-usedchannel in each channel group for quick recall. q Push [U/I/C] (both [ Y ] and [ Z ]) on the transceiver several times to select the de...
Page 15 - Microphone lock function
9 3 BASIC OPERATION 3 ■ Microphone lock function The microphone lock function electrically locks [ Y ] and [ Z ] keys on the supplied microphone. This prevents accidentalchannel changes and function access. ➥ While pushing and holding [HI/LO] on the microphone, turn power ON to toggle the Microphone...
Page 16 - SCAN OPERATION; Scan types
10 SCAN OPERATION 4 ■ Scan types Scanning is an efficient way to locate signals quickly over awide frequency range. The transceiver has Priority scan andNormal scan. When the Weather alert function is turned ON, the previouslyselected (last used) weather channel is also checked whilescanning. (p. 29...
Page 17 - Setting TAG channels; Starting a scan
11 4 SCAN OPERATION 4 ■ Setting TAG channels For more efficient scanning, add desired channels as TAGchannels or clear the TAG for unwanted channels.Channels that are not tagged will be skipped during scanning.TAG channels can be assigned to each channel group(U.S.A., International and Canada) indep...
Page 18 - Dualwatch
12 DUALWATCH/TRI-WATCH 5 ■ Description Dualwatch monitors Channel 16 while you are receiving on another channel; Tri-watch monitors Channel 16 and thecall channel while receiving another channel. Dualwatch/Tri-watch are convenient for monitor Channel 16 when you areoperating on another channel. ■ Op...
Page 19 - DSC OPERATION; MMSI code programming; MMSI code check
13 6 DSC OPERATION 5 6 ■ MMSI code programming The 9-digit MMSI (Maritime Mobile Service Identity: DSC selfID) code can be programmed at power ON. This code programming can be performed only twice. q Turn power OFF. w While pushing and holding [DSC] , turn power ON to enter MMSI code programming con...
Page 20 - DSC address ID; Programming address ID
14 6 DSC OPERATION ■ DSC address ID A total of 30 DSC address IDs (9-digit) can be programmedand named with up to 5 characters. D Programming address ID q Push [DSC] to enter the DSC menu. w Push [ Y ] or [ Z ] to select “ ,” and push [DSC] . e Push [ Y ] or [ Z ] to select “ ,” and push [DSC] . r P...
Page 21 - Deleting address ID; Position indication
15 6 DSC OPERATION 6 D Deleting address ID q Push [DSC] to enter the DSC menu. w Push [ Y ] or [ Z ] to select “ ” and push [DSC] . e Push [ Y ] or [ Z ] to select “ ”, then push [DSC] . • When no address ID is programmed, “ ” is displayed. r Push [ Y ] or [ Z ] to select the desired ID name for del...
Page 22 - Distress call; NEVER
16 6 DSC OPERATION ■ Distress call A Distress call should be transmitted if, in the opinion of theMaster, the ship or a person is in distress and requires imme-diate assistance. NEVER USE THE DISTRESS CALL WHEN YOUR SHIP OR A PERSON IS NOT IN AN EMERGENCY.A DISTRESS CALL CAN BE USED ONLY WHENIMMEDIA...
Page 23 - Transmitting DSC calls; Transmitting Individual call
17 6 DSC OPERATION 6 ■ Transmitting DSC calls To ensure correct operation of the DSC function, pleasemake sure you set the squelch correctly. (p. 7) D Transmitting Individual call The Individual call function allows you to transmit a DSC sig-nal to a specific ship only. q Push [DSC] to enter the DSC...
Page 24 - Transmitting Individual acknowledgement
18 6 DSC OPERATION t After transmitting the Individual call, standby on Channel70 until an acknowledgement is received. • “ ” scrolls at the channel comment indicator. y When the acknowledgement ‘Able to comply’ is received,the specified channel (in step e ) is selected with beeps automatically. Or,...
Page 25 - Transmitting Group call
19 6 DSC OPERATION 6 r Push [DSC] to enter the standby condition for Individual acknowledgement call. • “ ” appears at the channel comment indicator. t Push [DSC] to transmit the acknowledgement to the se- lected station. y After the Individual acknowledgement has been transmit-ted, the display chan...
Page 27 - Transmitting All Ships call
21 6 DSC OPERATION 6 D Transmitting All Ships call Large ships use Channel 70 as their ‘listening channel.’When you want to announce a message to these ships, usethe ‘All Ships call’ function. q Push [DSC] to enter the DSC menu. w Push [ Y ] or [ Z ] to select “ .” e Push [DSC] to enter the standby ...
Page 28 - Transmitting Position Request call
22 6 DSC OPERATION D Transmitting Position Request call Transmit a Position Request call when you want to know aspecified ship’s current position, etc. q Push [DSC] to enter the DSC menu. w Push [ Y ] or [ Z ] to select “ ,” then push [DSC] . e Push [ Y ] or [ Z ] to select the desired pre-programme...
Page 29 - Transmitting Position Report call
23 6 DSC OPERATION 6 D Transmitting Position Report call Transmit a Position Report call when you want to announceyour own position to a specific ship and to get an answer, etc. q Push [DSC] to enter the DSC menu. w Push [ Y ] or [ Z ] to select “ ,” and push [DSC] . e Push [ Y ] or [ Z ] to select ...
Page 30 - Receiving DSC calls; Receiving a Distress call; Receiving a Distress Relay call
24 6 DSC OPERATION ■ Receiving DSC calls D Receiving a Distress call While monitoring Channel 70 and a Distress call is received: ➥ The emergency alarm sounds. • Push any key to stop the alarm. ➥ “ DSC ” appears and “ ” scrolls at the channel comment indicator, then Channel 16 is automatically se-le...
Page 31 - Receiving an Individual call; Receiving a Group call
25 6 DSC OPERATION 6 D Receiving an Individual call While monitoring Channel 70 and an Individual call is re-ceived: ➥ The emergency alarm or beeps sound depending on thereceived category. ➥ “ DSC ” appears and “ ” scrolls at the channel comment indicator. ➥ Push any key to stop beep, then push [DSC...
Page 32 - Receiving an All Ships call; Receiving a Geographical Area call
26 6 DSC OPERATION D Receiving an All Ships call While monitoring Channel 70 and an All Ships call is received: ➥ The emergency alarm sounds when the category is ‘Dis-tress’ or ‘Urgency’; 2 beeps sound for other categories. ➥ “ DSC ” appears and “ ” scrolls at the channel comment indicator. ➥ Push a...
Page 33 - Receiving a Position Request call; Receiving a Position Reply call; Receiving a Position Report Reply call
27 6 DSC OPERATION 6 D Receiving a Position Request call While monitoring Channel 70 and a Position Request call isreceived: ➥ “ DSC ” appears and “ ” scrolls at the chan- nel comment indicator. ➥ Push any key to stop the beep, then push [DSC] to reply to the call; push any other key to ignore the c...
Page 34 - SET MODE; Set mode programming; Set mode operation; Set mode construction
28 SET MODE 7 ■ Set mode programming Set mode is used to change the conditions of the trans-ceiver’s functions: Scan type (Normal or Priority,) Scan re-sume timer, Weather alert, Dual/Tri-watch, DSC watch, Beeptone, Auto acknowledgement and Favorite channel function. Available functions may differ d...
Page 35 - Set mode items; Scan type
29 7 SET MODE 7 ■ Set mode items D Scan type The transceiver has 2 scan types: Normal scan and Priorityscan. Normal scan searches all TAG channels in the selectedchannel group. Priority scan searches all TAG channels in se-quence while monitoring Channel 16. D D Scan resume timer The scan resume tim...
Page 36 - DSC watch; Beep tone; Favorite channel
30 7 SET MODE D D DSC watch DSC watch monitors Channel 70 while you are receiving an-other channel.If a distress signal is received on Channel 70, the transceivermonitors Channel 16 and 70 alternately until the distress sig-nal disappears. If a signal is received on another channel,DSC watch pauses ...
Page 37 - CONNECTIONS AND MAINTENANCE; Connections
31 8 CONNECTIONS AND MAINTENANCE 7 8 ■ Connections q EXTERNAL SPEAKER LEAD Connects to an external speaker. w GPS RECEIVER LEAD Connects to a GPS receiver for position indication. • An NMEA0183 ver. 2.0 or 3.01 (sentence formatters RMC, GGA, GNS, GLL) compatible GPS receiver is required. Ask your de...
Page 38 - CONNECTIONS AND MAINTENANCE; Supplied accessories; Antenna
32 8 CONNECTIONS AND MAINTENANCE ■ Supplied accessories The following accessories are supplied: ■ Antenna A key element in the performance of any communication sys-tem is the antenna. Ask your dealer about antennas and thebest place to mount them. ■ Fuse replacement One fuse is installed in the supp...
Page 39 - Mounting the transceiver; Using the supplied mounting bracket; Optional MB-92 attachment
33 8 CONNECTIONS AND MAINTENANCE ■ Mounting the transceiver D D Using the supplied mounting bracket The universal mounting bracket supplied with your transceiverallows overhead or dashboard mounting. • Mount the transceiver securely with the 2 supplied screws (5 × 20) to a surface which is more than...
Page 40 - Optional MB-69 installation
34 8 CONNECTIONS AND MAINTENANCE ■ Optional MB-69 installation An optional MB-69 FLUSH MOUNT is available for mounting the transceiver to a flat surface such as an instrument panel. CAUTION: KEEP the transceiver and microphone at least 1 meter away from your vessel’s magnetic navigation com-pass. q ...
Page 41 - TROUBLESHOOTING
35 9 TROUBLESHOOTING PROBLEM POSSIBLE CAUSE SOLUTION REF. No sound from speaker. • Squelch level is too high. • Volume level is too low.• Speaker has been exposed to water. p. 7p. 7p. 9 • Set squelch to the threshold point.• Set [VOL] to a suitable level. • Drain water from the speaker. The transcei...
Page 43 - SPECIFICATIONS AND OPTIONS; Specifications; General
37 11 SPECIFICATIONS AND OPTIONS 10 11 ■ Specifications ï ï General • Frequency coverage : Transmit 156.025–157.425 MHz Receive 156.050–163.275 MHz • Mode : FM (16K0G3E) DSC (16K0G2B) • Channel spacing : 25 kHz • Current drain (at 13.8 V) : TX (at 25 W) 5.5 A max. Max. audio 1.5 A max. • Power suppl...
Page 44 - SPECIFICATIONS; Dimensions; Options
38 11 SPECIFICATIONS D D Dimensions ■ Options • MB-69 FLUSH MOUNT KIT For mounting the transceiver to a panel. • MB-92 DUST COVER For attaching to the front panel of the transceiver to protect itwhen not in use. Unit: mm (inch) 153.0 (6 1 ⁄ 32 ) 67.0 (2 5 ⁄ 8 ) 143.5 (5 21 ⁄ 32 ) 51.0 (2) 42.2 (1 21...
Page 45 - TEMPLATE
39 12 TEMPLATE 11 12 Unit: mm (inch) 153.0 (6 1 ⁄ 32 ) 139.0 (5 15 ⁄ 32 ) 67.0 (2 5 ⁄ 8 ) 53.0 (2 3 ⁄ 32 ) Cut here NOTE: The solid line is the line to use when cutting into the dash/helm. The dotted line shows the outline of the IC-M304’s front panel once the radio is fitted into thehole. Do not fo...
Page 47 - MEMO