Icom IC-M502, Service Manual

Page 1: ...VHF MARINE TRANSCEIVER iM502 SERVICE MANUAL ...

Page 2: ... pieces 8810006050 Screw Icom screw E7 IC M502 CHASSIS 10 pieces Addresses are provided on the inside back cover for your convenience REPAIR NOTES 1 Make sure a problem is internal before disassembling the transceiver 2 DO NOT open the transceiver until the transceiver is disconnected from its power source 3 DO NOT force any of the variable components Turn them slowly and smoothly 4 DO NOT short a...

Page 3: ... PREPARATION 5 1 5 2 PLL ADJUSTMENTS 5 2 5 3 TRANSMITTER ADJUSTMENTS 5 3 5 4 RECEIVER ADJUSTMENTS 5 4 SECTION 6 PARTS LIST SECTION 7 MECHANICAL PARTS 7 1 IC M502 7 1 7 2 HM 126 7 3 7 3 HM 127 OPTIONAL UNIT 7 3 SECTION 8 SEMI CONDUCTOR INFORMATION SECTION 9 BOARD LAYOUTS 9 1 VOL UNIT 9 1 9 2 DIAL UNIT 9 1 9 3 SQL UNIT 9 1 9 4 LOGIC UNIT 9 2 9 5 MAIN UNIT 9 4 9 6 CTRL UNIT 9 6 9 7 PWR CORD UNIT 9 6 ...

Page 4: ...uency deviation 5 0 kHz Spurious emissions 70 dBc Adjacent channel power 70 dB Residual modulation 40 dB Audio harmonic distortion Less than 10 at 60 deviation Audio frequency response 1 dB to 3 dB of 6 dB octave from 300 Hz to 2500 Hz Microphone impedance 600 Ω RECEIVER Receive system Double conversion superheterodyne system Intermediate frequencies 1st 21 7 MHz 2nd 450 kHz Sensitivity 0 32 µV 11...

Page 5: ...150 157 200 157 250 157 300 157 350 157 400 156 025 156 075 156 075 156 125 156 125 156 175 156 175 156 225 156 225 156 275 156 275 156 325 156 325 156 375 156 425 156 475 156 525 156 575 156 625 Receive 157 050 161 700 157 100 161 750 157 150 161 800 161 850 161 900 161 950 162 000 160 625 160 675 156 075 160 725 156 125 160 775 156 175 160 825 156 225 160 875 156 275 160 925 156 325 156 375 156 ...

Page 6: ...r Q12 2SC2954 1st mixer Q3 3SK166 Reset IC IC15 S 80928ANMP Located under side of the point Reference oscillator X2 CR 659 21 25 MHz 1st IF filter FI1 FI2 FL 310 Power module IC3 SC 1302 System clock X3 DMX 26S 36 768 kHz X4 CR 610 7 9872 MHz LOGIC UNIT System clock X1 CSTCC4 91MG 4 91 MHz Speaker SUB MPU IC1 µPD789405AGK A30 9EU LCD driver IC2 HD66712SA03FS DIAL UNIT SQL UNIT VOL UNIT MAIN UNIT ...

Page 7: ...789405AGK A30 9EU Data buffer circuit System clock X1 CSTCC4 91MG 8V regulator IC6 TA7808F Dimmer circuit Reset IC IC7 S 80928ANMP MIC amplifier IC4 NJM2125F 5V regulator IC5 TA78L05F Volume IC IC3 M62429FP AF MIC switch IC9 TC4W53FU AF amplifier IC2 TA7368F TOP VIEW ...

Page 8: ...nscrew 5 screws D and remove the LOGIC unit D D D D C C J1 J3 D Opening the transceiver case q Unscrew 6 screws A and remove the front unit w Unscrew 6 screws B and remove the rear panel E w Remove the 2 clips F e Disconnect microphone connector from J7 and CTRL connector from J3 and EX SP connector from J8 and EX GPS connector from J2 r Unsolder 10 point G t Unscrew 5 screws H and remove the MAIN...

Page 9: ...ig nals at the 1st mixer circuit Q3 to produce a 21 7 MHz 1st IF signal The 1st IF signal is applied to a pair of crystal filters FI1 FI2 to suppress out of band signals and is then amplified at the IF amplifier Q4 The amplified signal is applied to the 2nd mixer circuit IC1 4 1 4 2ND IF AND DEMODULATOR CIRCUITS The 2nd mixer circuit converts the 1st IF signal into a 2nd IF signal A double superhe...

Page 10: ...lifier to obtain the pre emphasis charac teristics The amplified signals are applied to the IDC amplifier IC13a pin 2 via the analog switch IC12 pins 9 8 and pins 4 3 and are passed through the splatter filter IC13b to suppress unwanted 3 kHz or higher signals The filtered sig nals are then applied to the modulation circuit 4 2 2 MODULATION CIRCUIT The modulation circuit modulates the VCO oscillat...

Page 11: ...es D6 D7 of the TX VCO to stabilize the oscillated frequency 4 3 3 RX LOOP The generated signal at the RX VCO Q8 D9 D10 enters the PLL IC IC2 pin 19 and is divided at the programmable divider section and is then applied to the phase detector section The phase detector compares the input signal with a refer ence frequency and then outputs the out of phase signal pulse type signal from pin 13 The pu...

Page 12: ...LCD driver for a dot matrix LCD DIMMER CIRCUIT CPU IC1 and Q2 Q3 Q8 are dimmer circuit and control the LCD backlight LED CONTRAST CIRCUIT CPU IC1 and Q1 Q4 are contrast circuit and control the 8 step display contrast 4 7 PORT ALLOCATIONS 4 7 1 SUB CPU LOGIC unit IC1 LINE HV HVS VCC 8V 5V T8 R8 DESCRIPTION The voltage from the connected DC power sup ply Same voltage as the HV line which is passed t...

Page 13: ...45 46 60 61 62 66 67 68 69 71 75 100 1 2 3 4 5 6 7 8 10 11 12 13 14 15 16 17 19 STRU SCON OPSTB PSTB CK DATA PTTM PTTS MMUTE SMUTE SP HI LO SEND TMUTE SRXD STXD CLRX Outputs control signal to the analog switch IC12 for passing through the optional VOICE SCRAMBLER unit UT98 or UT 112 Outputs ON OFF control signal for the optional VOICE SCRAMBLER unit UT 98 or UT 112 Outputs strobe signals for the o...

Page 14: ... generator Standard signal generator SSG Oscilloscope AC millivoltmeter External speaker Attenuator GRADE AND RANGE Frequency range 300 3000 Hz Measuring range 1 500 mV Frequency range 0 1 300 MHz Output level 0 1 µV 32 mV 127 to 17 dBm Frequency range DC 20 MHz Measuring range 0 01 20 V Measuring range 10 mV 10 V Input impedance 4 Ω Capacity 5 W or more Power attenuation 40 or 50 dB Capacity 50 W...

Page 15: ... power Low Connect an RF power meter or a 50 Ω dummy load to the antenna connector Transmitting MAIN Rear Panel Connect a digital multi meter or oscil loscope to check point CP1 Connect a digital multi meter or oscil loscope to check point CP2 Loosely couple the frequency counter to the antenna con nector 3 5 V 4 5 6 0 V 2 5 V 2 5 3 5 V 156 8000 MHz MAIN MAIN L13 Verify L10 Verify C70 Lock voltage...

Page 16: ...to J7 pin 5 with an AC millivoltmeter and set as Frequency 1 kHz Level 70 mV Set an FM deviation meter as HPF OFF LPF 20 kHz De emphasis OFF Detector P P 2 Transmitting Rear Panel Rear Panel Connect an RF power meter to the antenna connector Connect an FM deviation meter to the antenna con nector through an attenuator 25 W 4 3 kHz MAIN MAIN R84 R172 Output power adjustment R84 Frequency deviation ...

Page 17: ...e Connect an SSG to the antenna connector and set as Frequency 156 800 MHz Level 10 µV 97 dBm Modulation 1 kHz Deviation 3 5 kHz Receiving Operating channel ch16 SQUELCH control Max counterclockwise Connect an SSG to the antenna connector and set as Frequency 156 800 MHz Level 0 18 µV 122 dBm Modulation 1 kHz Deviation 3 5 kHz Receiving MAIN MAIN Connect a DC volt meter to check point CP3 Connect ...

Page 18: ...YJ 103 V 10 kΩ R48 7030003560 S RESISTOR ERJ3GEYJ 103 V 10 kΩ R49 7030003680 S RESISTOR ERJ3GEYJ 104 V 100 kΩ R50 7030003750 S RESISTOR ERJ3GEYJ 394 V 390 kΩ R51 7030003690 S RESISTOR ERJ3GEYJ 124 V 120 kΩ R52 7030003560 S RESISTOR ERJ3GEYJ 103 V 10 kΩ R53 7030003360 S RESISTOR ERJ3GEYJ 221 V 220 Ω R54 7030003360 S RESISTOR ERJ3GEYJ 221 V 220 Ω R55 7030003560 S RESISTOR ERJ3GEYJ 103 V 10 kΩ R56 70...

Page 19: ...210 GR TE85R Q8 1560000330 S FET 2SK210 GR TE85R Q9 1530002600 S TRANSISTOR 2SC4215 O TE85R Q10 1530002600 S TRANSISTOR 2SC4215 O TE85R Q11 1530002240 S TRANSISTOR 2SC3775 3 TB Q12 1530002340 S TRANSISTOR 2SC2954 T2B Q14 1520000380 TRANSISTOR 2SB1143 S Q15 1590000430 S TRANSISTOR DTC144EUA T106 Q16 1590000670 S TRANSISTOR FMW1 T148 Q17 1590000430 S TRANSISTOR DTC144EUA T106 Q18 1530002850 S TRANSI...

Page 20: ... 7030003620 S RESISTOR ERJ3GEYJ 333 V 33 kΩ R33 7310003590 S TRIMMER EVM 1XSX50 B24 203 R35 7030003660 S RESISTOR ERJ3GEYJ 683 V 68 kΩ R36 7030003420 S RESISTOR ERJ3GEYJ 681 V 680 Ω R37 7030003320 S RESISTOR ERJ3GEYJ 101 V 100 Ω R38 7030003300 S RESISTOR ERJ3GEYJ 680 V 68 Ω R39 7030003320 S RESISTOR ERJ3GEYJ 101 V 100 Ω R40 7030003280 S RESISTOR ERJ3GEYJ 470 V 47 Ω R41 7030003380 S RESISTOR ERJ3GE...

Page 21: ...4 7030003700 S RESISTOR ERJ3GEYJ 154 V 150 kΩ R205 7030003640 S RESISTOR ERJ3GEYJ 473 V 47 kΩ R208 7030003680 S RESISTOR ERJ3GEYJ 104 V 100 kΩ R209 7030003440 S RESISTOR ERJ3GEYJ 102 V 1 kΩ R210 7030003800 S RESISTOR ERJ3GEYJ 105 V 1 MΩ R211 7030003650 S RESISTOR ERJ3GEYJ 563 V 56 kΩ R212 7030003490 S RESISTOR ERJ3GEYJ 272 V 2 7 kΩ R218 7030003560 S RESISTOR ERJ3GEYJ 103 V 10 kΩ R219 7030003680 S ...

Page 22: ...608 JB 1H 102K T A C108 4030006860 S CERAMIC C1608 JB 1H 102K T A C109 4030007040 S CERAMIC C1608 CH 1H 180J T A C110 4030006860 S CERAMIC C1608 JB 1H 102K T A C111 4030006860 S CERAMIC C1608 JB 1H 102K T A C112 4030009510 S CERAMIC C1608 CH 1H 010B T A C113 4030006860 S CERAMIC C1608 JB 1H 102K T A C114 4030006860 S CERAMIC C1608 JB 1H 102K T A C115 4550002830 S TANTALUM TESVD2 1V 685M 12R C116 4...

Page 23: ...C 104KT N C283 4030006860 S CERAMIC C1608 JB 1H 102K T A C284 4030009510 S CERAMIC C1608 CH 1H 010B T A C285 4030006860 S CERAMIC C1608 JB 1H 102K T A C286 4030011600 S CERAMIC C1608 JB 1C 104KT N C287 4030006980 S CERAMIC C1608 CH 1H 070D T A C288 4030009910 S CERAMIC C1608 CH 1H 040B T A C289 4030009530 S CERAMIC C1608 CH 1H 030B T A C290 4030009500 S CERAMIC C1608 CH 1H 0R5B T A C291 4030009500...

Page 24: ...4120 S RESISTOR ERJ3GEYJ 203 V 20 kΩ R23 7030003560 S RESISTOR ERJ3GEYJ 103 V 10 kΩ R24 7030003450 S RESISTOR ERJ3GEYJ 122 V 1 2 kΩ R25 7030003560 S RESISTOR ERJ3GEYJ 103 V 10 kΩ R26 7510001150 S THERMISTOR NTCCM1608 4BH 103KC R27 7030003560 S RESISTOR ERJ3GEYJ 103 V 10 kΩ R28 7030004120 S RESISTOR ERJ3GEYJ 203 V 20 kΩ R29 7030003560 S RESISTOR ERJ3GEYJ 103 V 10 kΩ R30 7030003590 S RESISTOR ERJ3GE...

Page 25: ...012600 S CERAMIC C2012 JB 1A 105M T A C25 4030006900 S CERAMIC C1608 JB 1E 103K T A C26 4030012600 S CERAMIC C2012 JB 1A 105M T A C27 4030006850 S CERAMIC C1608 JB 1H 471K T A C28 4030011600 S CERAMIC C1608 JB 1C 104KT N C29 4030006860 S CERAMIC C1608 JB 1H 102K T A C30 4510004630 S ELECTROLYTIC ECEV1CA100SR C31 4030011810 S CERAMIC C1608 JB 1A 224K T N C32 4030007090 S CERAMIC C1608 CH 1H 470J T ...

Page 26: ...MP40 8850000690 Flat washer M3 3 7 0 5 SUS 6 MP41 8810006050 Icom screw E 7 6 MP43 8930052430 2345 A IC clip 1 MP44 8930052440 2345 B IC clip 1 MP45 8930053030 2345 earth plate 1 MP46 8930053030 2345 earth plate 1 MP47 8010004340 Edging rubber FX452 1 REF NO SECTION 7 MECHANICAL PARTS CHASSIS PARTS ORDER NO DESCRIPTION QTY S1 2230000250 Switch SPPH22014A 1 DS1 5030001880 LCD TSD0393 UFFDCW 1 EP1 8...

Page 27: ...2 CH CTRL UNIT SQL UNIT MAIN UNIT PWR CORD UNIT MP43 CH W1 CH J1 CT MP2 L DS1 L MP3 L EP1 L MP1 L S1 L MP36 CH MP8 CH W1 HM 126 CHASSIS J1 CT EP1 CH MP44 CH MP37 CH MP47 CH MP21 CH MP21 CH MP7 CH MP9 CH MP1 CH MP18 CH MP45 CH MP46 CH DIAL UNIT VOL UNIT LOGIC UNIT Unit abbreviations CH CHASSIS PARTS CT CTRL UNIT M MAIN UNIT L LOGIC UNIT ...

Page 28: ...510001090 Speaker 036D0801 1 MP1 8210017360 2417 front panel assembly BLACK 1 8210017390 2417 front panel A assembly WHITE 1 MP3 8930053510 2417 key board 1 MP4 8930053540 2417 PTT rubber 1 MP5 8930053990 2417 PTT sheet 1 MP6 8930053550 2417 PTT holder 1 MP7 8930053520 2417 top key 1 MP8 8930053760 2417 key plate 1 MP10 8930039000 1757 sheet 1 MP11 8810009180 Screw FT BT M2 5 NI ZU 3 MP12 89300537...

Page 29: ...ymbol CCB Symbol OY3 Symbol BR Symbol LL Symbol QO Symbol VY Symbol YG Symbol XY Symbol FJ Symbol K Symbol UK Symbol 16 Symbol F12 Symbol 06 Symbol 26 B E C B C E B C E B C E B E C B C E B E C B E C B E C B E C S D G S D G D S G2 G1 D S G2 G1 B E C B E C B E C B E C D G S B E C D G S DIODES 1SS355 1SS375 TL DA204 U DAN202 U DAP202U HSM88ASR TR HSU88TRF MA363 B MA77 MA8036 L MA8043 L MA8062 M Symbo...

Page 30: ...9 1 9 1 VOL UNIT SECTION 9 BOARD LAYOUTS 1 to MAIN unit W1 3 J1 VOL1 VOL2 GND 9 2 DIAL UNIT 1 4 J2 DIALB GND NC DIALA to LOGIC unit J3 9 3 SQL UNIT 1 to LOGIC unit J3 3 J1 SQLG SQLV SQL5V ...

Page 31: ...9 2 TOP VIEW 9 4 LOGIC UNIT ...

Page 32: ...1 39 38 64 65 1 20 21 40 41 61 80 60 102 103 128 KEYM GND 1 to HM 126 J2 2 J1 SP SP 5V SRESET VPP LMDA HV SP SP GND GND 8V MLDA HVS 1 13 14 2 to MAIN unit J4 J4 DIALB GND DIALA SQLG SQLV 5V to SQL and DIAL units 1 6 J3 ...

Page 33: ...12 10 J6 5V GND OPTIN SCON GND GND GND SCK SDATA OPSTB MICI DETI MICO DETO W1 to VOL unit J1 GND VOL1 VOL2 from CTRL unit J2 1 13 14 2 J3 GND DMDA CMDA VCC DSCMOD GND MICG ICF3 MDDA MCDA 5V VCC SAFO SMIC from LOGIC unit J4 1 13 14 2 J4 HVS MLDA 8V GND GND SP SP HV LMDA VPP SRESET 5V SP SP 1 8 to HM 126 J1 J7 SPMIC AF2 GND MIC MICE HANG PTT AF1 EXT SP 1 2 J8 AFG AF 1 2 to EXT GPS J2 NMEAI NMEAI 9 5...

Page 34: ...9 5 BOTTOM VIEW 1 1 1 1 7 14 8 8 4 5 7 14 8 4 8 5 ...

Page 35: ...TOP VIEW 4 5 1 8 1 13 to MAIN unit J3 14 2 J2 GND DMDA CMDA GND DSCMOD GND MICG PWR ICF3 MDDA MCDA 5V VCC SAFO SMIC 9 7 PWR CORD UNIT TOP VIEW 1 4 to MAIN unit J1 HV HV GND GND 9 8 HM 126 TOP VIEW GND SPMIC MICE MIC PTT KGND KEYM 1 7 J1 TOP VIEW ...

Page 36: ... BOTTOM VIEW HM 127 1 40 41 60 61 8 5 4 1 5 1 10 6 4 1 8 5 80 1 20 21 4 5 8 RRXDA PWRC RTXDA PTTC GND MICG AF MIC VCC 1 8 to IC M502 CTRL unit J1 J1 BOTTOM VIEW CTRL BOTTOM VIEW HM 126 BOTTOM VIEW PWR CORD ...

Page 37: ... R8 Q5 2SC4215 Q9 2SC4215 IC2 µPD3140GS Q8 2SK210 D9 D10 MA363B AF VR VOL UNIT X1 4 91 MHz SQLV SUB MPU KEY BOARD DIAL UNIT IC2 HD66712SA03FS IC1 µPD789405AGK A30 9EU D5V ENCODER SQL UNIT DS1 Q1 Q4 2SK1069 LCD CONT LCD DRIVER DIM CTRL Q2 2SC4116 Q3 2SB1132 Q8 2SC4116 DS2 DS17 SML 311YT Q5 DTA144EU Q6 DTC144EU SRESET VCC SP Q32 2SC4116 D23 1SS355 RL2 FTR F3AA012E IC14 LA4425A IC13B NJM4558M Q7 2SK2...

Page 38: ...YT 1 2 3 4 5 6 COM15 COM14 COM13 COM12 COM11 COM10 COM9 SEG6 SEG7 SEG8 SEG9 SEG10 SEG16 SEG17 SEG18 SEG19 SEG20 SEG26 SEG27 SEG28 SEG29 SEG30 SEG36 SEG37 SEG38 SEG39 SEG40 SEG46 SEG47 SEG48 SEG49 SEG50 SEG56 SEG57 SEG58 SEG59 SEG60 COM1 COM2 COM3 COM4 COM5 COM6 COM7 LS0 LS1 LS2 LS3 LC2 LC3 COM17 COM18 COM19 COM20 COM21 COM22 COM23 SEG1 SEG2 SEG3 SEG4 SEG5 SEG11 SEG12 SEG13 SEG14 SEG15 SEG21 SEG22 ...

Page 39: ...0 R58 100 R60 2 2k L16 0 1µ Q10 2SC4215 R61 220 C99 0 001 C100 0 001 C101 12p D11 MA77 D12 MA77 R62 1k R64 39 R65 2 2k R66 390 C104 0 001 C105 0 001 R67 10k R68 10k L17 82n Q11 2SC3775 C107 0 001 R70 10 C108 0 001 C109 18p R71 1k R291 47k D13 1SS355 R59 3 3k C106 47p R69 100 T8 R55 68k L15 0 1µ Q9 2SC4215 R56 680 C278 0 001 L12 3 9µ D10 MA363B D9 MA363B L13 LB 257 C297 1p C298 2p C299 4p Q8 2SK210...

Page 40: ...C328 C195 0 01 C192 1 C193 1 R280 10k R285 100k R281 820 R296 10k R295 10k R286 100k R137 R284 0 1 2 7k 100k OPT BUS MAIN BUS SAFO 5V SMIC R117 1k C182 0 22 C183 0 027 C184 0 027 R119 8 2k R120 560k R121 180k R122 2 7k Q24 2SC4116 R123 330 R124 33k R125 33k C185 0 0022 C186 820p Q25 2SC4116 R126 2 2k R127 100k Q26 2SJ144 R128 470k C190 0 0039 Q27 2SJ144 R129 470k 2SJ144 Q46 C191 0 0039 R130 100k R...

Page 41: ... SI RXD P21 SO TXD P20 SCK ASCK P53 P52 P51 P50 40 AVREF 21 S10 80 P40 KR0 SEG10 SEG19 SEG18 SEG17 SEG16 SEG15 SEG14 SEG13 SEG12 SEG11 10k R7 10k R6 10 C1 SKQLLC S4 CP7 10k R8 PTT 10k R9 CH16 6 8k R20 10KEY S7 PTT 22 C37 0 1 C28 10 C30 AF5V 22 C35 5V 0 001 C29 DTC144EU Q5 DTB123EK Q6 100k R45 0 01 C53 1M R65 1M R66 47p C32 100k R44 NJM2125F IC4 5 4 2 1 3 MIC CP6 MICG SKB 2746 LPC MC1 CP5 CP4 470k ...

Page 42: ...PMIC KEYM MICE 1 2 3 4 5 6 7 J1 KGND 1 2 3 4 5 6 7 P3 PTT MIC MICE SPMIC KEYM UP ON 2 0V DN ON 3 0V H L ON 3 8V GND KGND W1 W4 W3 R5 15 W2 C1 470p C2 470p R1 12k SP1 S36G04K 4 MC1 KUC2123 030245 UP PTT DN S1 SKHHLP014A S2 S3 R2 6 8k R3 15k BLUE HANG SPMIC GND MIC MICE HANG PTT AF1 AF2 RED BLUE BLACK WHITE OUT IN 1 2 3 4 5 6 7 8 P1 R4 33k S4 S2 S4 SKHHAM024A H L ...

Page 43: ...one 425 454 8155 Fax 425 454 1509 URL http www icomamerica com Customer Service Phone 425 454 7619 Glenwood Centre 150 6165 Highway 17 Delta B C V4K 5B8 Canada Phone 604 952 4266 Fax 604 952 0090 URL http www icomcanada com A B N 88 006 092 575 290 294 Albert Street Brunswick Victoria 3056 Australia Phone 03 9387 0666 Fax 03 9387 0022 URL http www icom net au 146A Harris Road East Tamaki Auckland ...

Page 44: ...1 1 32 Kamiminami Hirano ku Osaka 547 0003 Japan S 13710HZ CD 2000 Icom Inc ...