Icom IC-M304 Service Manual Download Page 15 | Manualshive

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Icom IC-M304 Service Manual Download Page 15

5 - 3

5-3 TRANSMIT ADJUSTMENT

ADJUSTMENT

ADJUSTMENT CONDITION

OPERATION

VALUE

TRANSMIT
OUTPUT
POWER

1 • Channel

: CH16 (156.800 MHz)

• Output power

: High

• Connect an RF power meter to the ant-
enna connector.
• Transmitting

Adjust R135 (PWR).

23.5 W

DEVIATION

1 • Channel

: CH16 (156.800 MHz)

• Output power

: Low

• Connect an audio generator to the ‘MIC’
line (see the picture below), and set as;
Frequency

: 1 kHz

Level

: 140 mV

• Connect an FM deviation meter to the ant-
enna connector through an attenuator,
and set as ;
HPF

: OFF

LPF

: 20 kHz

De-emphasis : OFF
Detector

: (P–P)/2

• Transmitting

Adjust R184 (DEV).

±4.3 kHz

• ADJUST&CHECK POINTS LOCATION (TRANSMIT)

KEYM

GND

MIC

MICG

PTT

1

5

+

–

–

+

AC millivoltmeter

Audio generator

[PTT]

J2

R135 (PWR)

TRANSMIT OUTPUT POWER

ADJUSTMENT POINT

R184 (DEV)

DEVIATION

ADJUSTMENT POINT

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14
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17
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Summary of Contents for IC-M304

Page 1: ...S 14311XZ C1 Dec 2006 VHF MARINE TRANSCEIVER iC m304 ...

Page 2: ...FNG IC M304 MAIN UNIT 5 pieces 8820001210 Screw 2438 screw IC M304 CHASSIS 10 pieces Addresses are provided on the inside back cover for your convenience Icom Icom Inc and logo are registered trademarks of Icom Incorporated Japan in the United States the United Kingdom Germany France Spain Russia and or other countries ORDERING PARTS 1 Make sure a problem is internal before disassembling the trans...

Page 3: ...OWER SUPPLY CIRCUITS 4 4 4 7 PORT ALLOCATIONS 4 5 SECTION 5 ADJUSTMENT PROCEDURES 5 1 PREPARATION 5 1 5 2 FREQUENCY ADJUSTMENT 5 2 5 3 TRANSMIT ADJUSTMENT 5 3 5 4 RECEIVE ADJUSTMENT 5 4 SECTION 6 PARTS LIST SECTION 7 MECHANICAL PARTS AND DISASSEMBLY SECTION 8 SEMICONDUCTOR INFORMATION SECTION 9 BOARD LAYOUTS SECTION 10 BLOCK DIAGRAM SECTION 11 VOLTAGE DIAGRAM 11 1 LOGIC UNIT Incl SQL and VR UNITs ...

Page 4: ...5 W Less than 56 dBc at 1 W Adjacent channel power More than 70 dB Audio harmonic distortion Less than 10 at 60 deviation Residual modulation More than 40 dB Audio frequency response 1 dB to 3 dB of 6 dB oct from 300 Hz to 2500 Hz Microphone impedance 2 kΩ M RECEIVER Receive system Double conversion superheterodyne system Intermediate frequencies 1st IF 21 7 MHz 2nd IF 450 kHz Sensitivity 13 dBµ t...

Page 5: ...1 6 5 1 A 2 6 5 7 7 0 6 1 5 7 1 6 5 1 3 6 5 7 1 6 5 1 5 7 1 6 5 1 A 3 6 5 2 8 0 6 1 5 2 2 6 5 1 4 6 4 6 5 2 2 6 5 1 5 2 2 6 5 1 A 4 6 A 4 6 5 7 8 0 6 1 5 7 2 6 5 1 5 6 5 7 2 6 5 1 5 7 2 6 5 1 A 5 6 A 5 6 A 5 6 5 2 9 0 6 1 5 2 3 6 5 1 6 6 A 6 6 A 6 6 1 5 2 3 6 5 1 5 2 3 6 5 1 A 6 6 7 6 2 5 7 3 6 5 1 5 7 3 6 5 1 7 6 7 6 0 5 0 7 5 1 0 5 0 7 5 1 A 1 2 A 1 2 A S U 0 5 6 1 6 1 0 5 0 7 5 1 1 2 1 2 N A C ...

Page 6: ...er FI3 LT450EW DSC DECODER IC3 NJM2211M IDC LPF IC10 NJM4558M MIC MUTE SWITCH IC7 TC7W66EU 1st IF filters FI1 FL 368 FI2 FL 399A IF IC IC1 TA31136FN PLL IC IC8 uPD3140GS VCO DIMMER CONTROL CIRCUIT Q2 KTA1664 Q3 Q4 KTC4075 CPU IC1 M37560EFGP EEPROM IC4 HN58X2464T1 TONE BUFFER IC6 NJM2904M ...

Page 7: ...aker cable F 2 points and DC cable G 2 points on the bottom side of the MAIN UNIT w Unsolder the antenna connector B 3 points e Remove the clip C r Unscrew 2 screws D and 7 screws E to remove the MAIN UNIT 3 Removing the LOGIC UNIT q Disconnect 2 cables I and K w Unsolder 2 points H e Unscrew 4 screws J to remove the LOGIC UNIT A A A RONT ANEL CASE E C E B D G F speaker MAIN UNIT DC cable I J K H ...

Page 8: ...n ratio and obtains stable receiver gain The FM IF IC IC1 contains the 2nd local oscillator 2nd mixer limiter amplifier quadrature detector and noise detector circuits etc The 1st IF signal from Q4 is applied to the 2nd mixer section of IC1 pin 16 and is mixed with a 21 25 MHz 2nd LO signal generated at the PLL circuit using the reference frequency 21 25 MHz to produce a 450 kHz 2nd IF signal The ...

Page 9: ... has amplification output capabilities of about 25 W with 10 mW input The output from IC4 pin 4 is passed through the antenna switching circuit D1 and is then applied to the antenna connector via the low pass filter 4 1 5 AF AMPLIFIER CIRCUIT MAIN AND FRONT UNITS The AF amplifier circuit amplifies the detected signals to drive a speaker The AF circuit includes an AF mute circuit for the squelch AF...

Page 10: ...the loop filter R211 R213 C252 C254 and is then applied to varactor diodes D13 D14 of the VCO to stabilize the oscillated frequency 4 3 4 VCO CIRCUIT MAIN UNIT The VCO outputs from Q13 Q14 are buffer amplified at the buffer amplifiers Q15 and Q16 and are then sent to the Tx Rx switch D16 and D17 The receive LO signal is applied to the 1st mixer circuit Q2 through a low pass filter and the transmit...

Page 11: ...1 RESET CIRCUIT IC5 which is a reset IC outputs a reset signal HIGH pulse signal to the CPU IC1 pin 33 from pin 1 when the transceiver turns power ON LOW BATTERY DETECTOR HVS voltage is divided by R14 and R15 and is applied to the low battery detector section in the CPU IC1 pin 1 DIMMER CIRCUIT CPU IC1 Q2 Q3 and Q4 compose dimmer circuit The circuit controls 4 steps LCD backlight DS2 DS7 UART PORT...

Page 12: ... to the attenuator D22 High Attenuator ON 57 PTT Input port for the PTT switch HM 150B SW S1 Low PTT key is pushed 60 UNLK Input port for the UNLK signal from the PLL IC IC1 pin7 High PLL circuit is unlocked Pin NO Port name Description 61 DTRS Input port for the DISTRESS key LOGIC BOARD S9 Low DISTRESS key is pushed 62 RMUTEP Outputs AF Public Address mute signal to the AF mute circuit IC4 pin12 ...

Page 13: ...or better Sensitivity 100 mV or better AC millivoltmeter Measuring range 10 mV to 10 V FM deviation meter Frequency range 30 300 MHz Measuring range 0 to 10 kHz External speaker Input impedance 4 Ω Capacity More than 5 W Audio generator Frequency range 300 3000 Hz Output level 1 500 mV Attenuator Power attenuation 40 dB Capacity More than 30 W 5 1 PREPARATION CONNECTIONS FM IC M304 deviation meter...

Page 14: ...Output power Low Connect a power meter to the ant enna connector Transmitting 1 4 2 4 V Verify REFERENCE FREQUENCY 1 Channel CH16 156 800 MHz Output power Low Connect a power meter to the ant enna connector Transmitting 1 Loosely couple a frequency counter to the ant enna connector 2 Adjust C257 REF 156 800 MHz ADJUST CHECK POINTS LOCATION FREQUENCY LV LOCK VOLTAGE CHECK POINT C57 REF RECEIVE SENS...

Page 15: ...ower Low Connect an audio generator to the MIC line see the picture below and set as Frequency 1 kHz Level 140 mV Connect an FM deviation meter to the ant enna connector through an attenuator and set as HPF OFF LPF 20 kHz De emphasis OFF Detector P P 2 Transmitting Adjust R184 DEV 4 3 kHz ADJUST CHECK POINTS LOCATION TRANSMIT KEYM GND MIC MICG PTT 1 5 AC millivoltmeter Audio generator PTT J2 R135 ...

Page 16: ... and set as Frequency 156 800 MHz Level 0 dBu 107 dBm Modulation 1 kHz Deviation 3 0 kHz Receiving 1 Connect a DC voltmeter to the check point RSSI 2 Adjust in sequence L6 L7 L8 and L9 Repeate the adjustment at least twice Maximum voltage ADJUST CHECK POINTS LOCATION RECEIVE L6 L7 L8 L9 RSSI RECEIVE SENSITIVITY CHECK POINT RECEIVE SENSITIVITY ADJUSTMENT POINTS The output level of the standard sign...

Page 17: ... 32 7 C23 4030008890 S CER C1608 JB 1H 273K T B 30 44 5 C25 4030006900 S CER C1608 JB 1H 103K T B 25 2 42 1 C26 4030006860 S CER C1608 JB 1H 102K T B 29 14 C31 4030009650 S CER C1608 CH 1H 240J T B 43 5 40 1 C32 4030007050 S CER C1608 CH 1H 220J T B 42 1 41 1 C41 4030006850 S CER C1608 JB 1H 471K T B 9 6 9 S Surface mount LOGIC UNIT REF ORDER DESCRIPTION M H V NO NO LOCATION C42 4030006850 S CER C...

Page 18: ...3GEYJ 100 V 10 T 48 8 67 4 S Surface mount MAIN UNIT REF ORDER DESCRIPTION M H V NO NO LOCATION R111 7030003560 S RES ERJ3GEYJ 103 V 10 k T 47 64 R112 7030003580 S RES ERJ3GEYJ 153 V 15 k T 49 6 60 2 R113 7030003370 S RES ERJ3GEYJ 271 V 270 T 50 9 64 R126 7030003680 S RES ERJ3GEYJ 104 V 100 k T 57 8 66 4 R127 7030003480 S RES ERJ3GEYJ 222 V 2 2 k T 57 2 68 6 R128 7030003370 S RES ERJ3GEYJ 271 V 27...

Page 19: ... 500V C172 4030006860 S CER C1608 JB 1H 102K T T 69 3 60 3 C173 4030006860 S CER C1608 JB 1H 102K T T 73 5 60 3 C174 4010005430 CER HM60SJ CH 050C 500V C175 4030006860 S CER C1608 JB 1H 102K T T 82 9 52 9 C176 4030006860 S CER C1608 JB 1H 102K T T 63 5 64 5 C177 4030006900 S CER C1608 JB 1H 103K T T 70 9 53 4 C178 4030006860 S CER C1608 JB 1H 102K T T 66 51 3 C179 4030006850 S CER C1608 JB 1H 471K...

Page 20: ...N 312 C Super White 2 8610011640 KNOB N 312 B Gray 2 MP5 8930014280 Speaker net FX 706 1 MP6 8810010021 Screw BTB0 2 6X8NI ZC3 BT 4 MP7 8930052010 2345 SHAFT 1 MP8 8930060481 2685 SPRING 1 1 MP9 8110008990 2989 D COVER 1 MP10 8930060470 2685 SHAFT ANGLE 1 MP11 8930060490 2685 F BUSH PLATE 1 MP12 8930052280 O ring AC 2 MP13 8930055841 2490 EARTH SPRING 1 1 REF ORDER DESCRIPTION QTY NO NO DS1 503000...

Page 21: ...P11 F MP12 F MP12 F MP13 C MP10 C MP19 C MP12 C MP12 C MP12 C MP8 C MAIN UNIT UNiT ABBREVIATIONS C CHASSIS PARTS F FRONT UNIT L LOGIC UNIT M MAIN UNIT VR VR UNIT SQL SQL UNIT VR UNIT SQL UNIT LOGIC UNIT MP6 F EP2 L MP1 L MP3 L DS1 L MP2 L NOTE 1 NOTE 1 NOTE 2 NOTE 2 E F 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 32 86 3 3 13 32 137 0 5 13 32 133 5 1 4 ...

Page 22: ... KRC404 Marking ND KTA2015Y Marking Z KTC4080 Marking Q TRANSISTERS AND FETs 1SS355 Marking 5D KDS122 Marking C3 1SS321 Marking F9 DSA3A1 Marking green HSM88ASRTR Marking C3 HVC350BTRF Marking B0 KDV214E Marking UO MA2S077 Marking S MA742 Marking M1U DIODES B E C B E C B E C G1 G2 S D B C C E B1 E B2 C1 C2 B E C B E C B E C B E C A C A C C A1 A2 green A C A C A C A C A C ...

Page 23: ... L L10 L12 L13 L21 2 2 L 3 2 L L26 L28 L29 1 3 L 2 3 L 5 3 L 6 3 L 1 P M 3 P M 1 Q Q2 Q4 5 Q Q6 7 Q Q11 2 1 Q 3 1 Q Q14 Q15 Q16 Q17 9 1 Q 0 2 Q 1 2 Q 2 2 Q Q23 Q25 6 2 Q 1 3 Q Q32 3 3 Q Q34 Q35 Q36 4 R 5 R R6 7 R 8 R 9 R 0 1 R R12 4 1 R R16 7 1 R 1 2 R 5 2 R 6 2 R R27 8 2 R 1 3 R R32 3 3 R R34 R35 R36 R37 R38 R39 R41 2 4 R R43 R44 R45 R46 7 4 R 8 4 R 9 4 R R50 1 5 R R52 3 5 R 4 5 R R55 R56 R57 8 5...

Page 24: ...0 V15 V20 V25 V30 V35 V40 V45 V50 LQS B 6660 H0 H5 H10 0V 5V 01V H0 H5 H10 0V 5V 01V 51V P S P S D N G 0 H 5 H 0 1 H 5 1 H 0 2 H 5 2 H 0 3 H 5 3 H 0 4 H 5 4 H 0 5 H 5 5 H 0 6 H 5 6 H 0 7 H 5 7 H 0 8 H 5 8 H 0 9 H 5 9 H 0 0 1 H 5 0 1 H 0 1 1 H V0 V5 V10 V15 V20 V25 V30 V35 V40 V45 V50 V55 V60 V65 V70 V75 V80 MAIN UNIT BOTTOM VIEW LOGIC UNIT BOTTOM VIEW SQL UNIT BOTTOM VIEW VR UNIT BOTTOM VIEW IC4 M...

Page 25: ...A1664 IC4 HN58X2464TI IC5 S 80942CNMC IC2 PC357N6 IC3 TC7S14FU Q6 7 KTC4075x2 IC6 LA4425A I C10A IC10B Q5 KTC4075 IC3 NJM2211M Q13 14 2SC4226x2 Q26 KTC4080 D16 17 Q19 20 KRC404 I C4 S AV35A I F D21 22 Q21 FMW1 D1 D2 D3 KDS122 IC7B TC7W66FU PROTECT CTRL D25 DSA3A1 HVS T5 HV REVERSE CTRL T5 5V CONNECT R5 Q31 KTA2015 R8 R5 Q22 KRC402 SQL UNIT IC6A NJM2904M 2nd LO TC7W66FU IC9 KIA7805API EXT SP I NT S...

Page 26: ... C4 470P C2 KTC4075 Q3 0 001 C26 10K R16 0 1 C6 DN S4 470P C41 DS 4 SML 311YT 0 01 C25 0 001 C14 DS 6 RY SP110UHY24 0 001 C12 47K R25 CP1 CP10S CP10S CP7 10K R4 150 R40 10K R56 6 8K R54 22 C22 CP4 CP10S 1SS355 D2 0 0047 C16 DTC114TU Q6 10K R64 27 R21 1K R29 15K R37 100K R61 0 01 C3 KTC4075 Q4 CH1 6 S3 10K R5 TC7S14FU IC3 1 2 3 4 5 27 R22 CP10S CP6 HN58X2464TI IC4 1 A0 2 A1 3 A2 4 VSS 5 SDA 6 SCL 7...

Page 27: ...A C113 2 2K R127 Q19 KRC404 0 0022 C93 10P C149 47K R170 2SC4226 Q14 FI 2 FL 399A KDV214E D5 0 68 MSVA C252 15K R76 470P C117 18P C259 KIA7805API IC9 I O COM 470 C213 470P C199 Q20 KRC404 220P C73 2 2K R108 0 1 C249 220 R135 47 R71 0 022 C91 72 0N L22 KRC404 Q12 0 001 C217 470K R64 LA 253 L31 470P C297 0 001 47K R84 1M R155 0 022 C90 KTC4075 Q7 0 22 C103 Q22 KRC402 390 R67 330 R215 LT450EW FI3 I O...

Page 28: ...P16 8810010230 Screw BiH M4X8 ZK 1 MP17 8850002000 SPRING WASHER M4 SUS 1 MP19 8810010240 Screw BT B0 2X6NI 2 MP20 8930061700 2715 PTT PLATE 1 S3 MC1 W2 1 C W1 S4 2 C 1 1 2 2 3 3 4 4 5 5 1 R R3 R2 R4 L4 12k 470p 0 022 0 22u 0 22u 6 8k 15k 33k S2 S1 L3 PTT Y Z HI LO PTT MICG MIC GND KEYM W1 CHASSIS UP ON 2 0V DN ON 3 0V HI LO ON 3 8V M Mounted side T Mounted on the Top side B Mounted on the Bottom ...

Page 29: ...ICOMAMERICA COM USTOMER 3ERVICE 0HONE LENWOOD ENTRE IGHWAY ELTA 6 ANADA 0HONE AX 52 HTTP WWW ICOMCANADA COM MAIL INFO ICOMCANADA COM 5NIT ARDEN 2OAD LAYTON 6 USTRALIA 0HONE AX 52 HTTP WWW ICOM NET AU MAIL SALES ICOM NET AU ARRIS 2OAD AST 4AMAKI UCKLAND EW EALAND 0HONE AX 52 HTTP WWW ICOM CO NZ MAIL INQUIRIES ICOM CO NZ 2OOM TH LOOR ONG 3ILVER ANSION O 9ONG ING 2OAD AIDIAN ISTRICT EIJING HINA 0HONE...

Page 30: ...1 1 32 Kamiminami Hirano ku Osaka 547 0003 Japan S 14311XZ C1 2006 Icom Inc ...

Page 31: ...T FRONT LOGIC VR SQL and HM 164B Black U M304 02 FRONT FRONT LOGIC VR SQL and HM 164SW Super White U M304 03 FRONT FRONT LOGIC VR SQL and HM 164G Gray ORDER NO UNIT NAME 0329890102 U M304 01 MAIN MAIN CHASSIS CHASSIS Incl MAIN UNIT HM 164 ORDER NO UNIT NAME Optional product Optional product Optional product HM 164B Black HM 164SW Super White HM 164G Gray ...

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