Cobra MR HH325VP Service Manual
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Cobra MR HH325VP Service Manual

Marine handheld transceiver
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Specifications ...............................................................................................................................2
Theory of Operation ..........................................................................................................5
Block Diagram .............................................................................................................................7
Disassembly Instructions ..............................................................................................................8
Alignment Procedures ...............................................................................................................9
Adjustment Procedure ...............................................................................................................10
Wiring Diagram .........................................................................................................................12
Printed Circuit Board ..................................................................................................................13
Troubleshooting ..........................................................................................................................16
Exploded View ..........................................................................................................................17
Mechanical Parts List .................................................................................................................19
Electrical / Packing / Other Parts List ..........................................................................................21
IC Lead Identification and Internal Diagram ............................................................................37
Transistor Lead Identification .........................................................................................44
Voltage Chart .............................................................................................................................46
Schematic Diagram.....................................................................................................................50
Version:01 Date: Nov 27,2007

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  • Page 1: Table Of Contents

    Page Specifications .................……………………….………...……2 Theory of Operation .……………….........………..………………..….5 Block Diagram ................……...…………………………………7 Disassembly Instructions ............………..………………………...…8 Alignment Procedures ...……………...........……....…...…………………9 Adjustment Procedure ……..…………..............…………………10 Wiring Diagram ……..............…………..…………………….……12 Printed Circuit Board ..............……………..……………………...13 Troubleshooting …...................………...……………………16 Exploded View ..............…………………………..………………..17 Mechanical Parts List ..............…………………….…………….…19 Electrical / Packing / Other Parts List ..........………………………...…………..21 IC Lead Identification and Internal Diagram ....………………………………………..………..37 Transistor Lead Identification …………………………………………………………….……...……….44 Voltage Chart ................………………….……………...……46...
  • Page 2 SPECIFICATIONS Measurement Conditions Frequency Range:Transmit 156.025 To 157.425 Frequency Range:Receive 156.050 To 162.025 Number of Channels 59 INT Channels 57 USA Channels 57 Canada Channels Memory Channels All marine channels Oscillate Mode Modulation FM(16K0G3E) Channel Spacing Frequency Stabllity ±10 Stantard Operation Temperature °C -20 To+55 Normal Working Voltage...
  • Page 3 78.4MHz ≥ 46 39.2/ 146.8/ 154.4/ 155.9/ 157.8/ 158.2/ 163.9/ 249.4MHz ≥ 50 OTHER freq. ≥ 70 Adjacent ch.Rejection ≥ 55 Image rejection ≥ 65 Intermod rejection (3-Gen.Method) ≥ 60 Scan time. per channel ≤ 200 Speaker output 8Ω load @ Max Vol. ≥...

  • Page 4: Theory Of Operation

    THEORY OF OPERATION This PLL - controlled VHF marine transceiver provides an accurate and stable multi-channel operation. The transceiver consists of 6 main sections: Transmitter Receiver Low Voltage Detection Vibration Alert PLL (Phase Lock Loop) Circuit Memory Backup Transmitter The audio is picked up from the internal MIC, the audio signal is then amplified by Audio Amplifier, U4 LM324 (2/4), U4 (3/4) and filtered by a low pass filter U4 LM324 (4/4).
  • Page 5 switching circuit to receive. The received RF signal is sent to a SAW filter F1 to filter out-of-band signal. The RF amplifier Q7 amplifies signals within the range of the frequency coverage and passes though another saw filter F2 to further filter out-of-band signals. The RF signal then is mixed with the local oscillation frequency by the mixer Q8.

  • Page 6: Block Diagram

    BLOCK DIAGRAM RESET V +7.2 AUDIO MUTE BEEP...

  • Page 7: Disassembly Instructions

    DISASSEMBLY INSTRUCTIONS To remove the front and rear panels from the main chassis: 1. Remove the rubber antenna, SPK/MIC knob and the VOL/SQL knob from the main unit. 2. Remove 4 screws from the rear housing of main unit. 3. Detach the die cast from the front housing.

  • Page 8: Alignment Procedures

    ALIGNMENT AND PROCEDURES This unit has been fully aligned at the factory before shipment and does not normally require further adjustment. When necessary, however, the unit may be aligned as indicated below. Do not adjust any circuit in this radiotelephone unless you understand the circuit operation and have experience in adjusting the radiotelephone.

  • Page 9: Adjustment Procedure

    ADJUSTMENT PROCEDURE Step Adjustment Test Point Procedure 1. Connect digital voltmeter to TP1 on RF PCB. 2. Set CH01. L22 Receive 3. Adjust L22. 4. TP1 voltage 1.2~1.6V DC. 1. Connect a digital voltmeter to TP1 on RF PCB. 2. Set CH01. L23 Transmit 3.
  • Page 10 Main PCB Top View Bottom View...

  • Page 11: Wiring Diagram

    WIRING DIAGRAM...

  • Page 12: Printed Circuit Board

    PRINTED CIRCUIT BOARD Main PCB Top View...
  • Page 13 PRINTED CIRCUIT BOARD Main PCB Bottom View...
  • Page 14 PRINTED CIRCUIT BOARD LCD PCB Top View Bottom View Charger PCB Top View Bottom View...

  • Page 15: Troubleshooting

    TROUBLE SHOOTING Item Symptom Possible Cause Defective power switch VR3. Unit does not turn on. Check the battery voltage. Defective regulator U8. Speaker no sound with Defective volume control. AF signal applied to Defective speaker. volume control Defective U11 and/or associated components. Check squelch control.

  • Page 16: Exploded View

    MAIN UNIT EXPLODED VIEW MAIN UNIT EXPLODED VIEW...
  • Page 17 CHARGER UNIT EXPLODED VIEW...

  • Page 18: Mechanical Parts List

    MAIN UNIT EXPLODED VIEW PART LIST Ref.No. Description Mfr's Part No. CAB FNT MU COBRA TM832USL ABS GREY DS 022 ROHS 051L003546C017 INSU WATERPROOF FILM D9.5MM ROHS 058LD95047-20006 INSU SHT- NYLON D37.3 TM832EUL SPEAKER FELT 058L002895C013 KEY RUB FUN -6K MAIN...
  • Page 19 Description Mfr's Part No. PLAS MOUNIG- BAT PACK POCKET ABS BLK 3U2X TM832EUL ROHS 056L006982C011 CAB FNT CHG COBRA TM832USL ABS BLK 3U2X CM110-007 ROHS 051L003473D029 055L002779C020 LENS LTGD LED LENS FOR CHG TM832EUL PMMA TRANSPARENT ROHS CONT COM CHARGE-- TM832EUL...

  • Page 20: Electrical / Packing / Other Parts List

    METAL PLATE ----- T03 S/S LCD MOUNTING TM832EUL ROHS 063L003946D016 INLAY KEY- SUS304+ADHESIVE TM833EUL COBRA ROHS 076L002625-015 INLAY KEY- SUS304+ADHESIVE TM832EUL UNIT COBRA ROHS 076L002626-012 CUSH SPON 40*4*3MM TM832 ROHS 089L003426-017 DOUBLE COATED WHITE SPONGE 9*7 *1mm 089L070901-30007 TM832USL/MAIN/SOLDERING/PCBA/ COBRA/US/BLK/REV.0...
  • Page 21 PARTS LIST-CONTINUED MAIN PCB ASSEMBLY Ref.No. Description Mfr's Part No. TM832EUL/MAIN/TOP/SMD/PCBA/ COBRA/EU/BLK/REV.0 A28P4030101L0002 CAP-CSM 30--P/J 50-V 0603--COG MURATA GRM1885C1H300JA01D ROHS 003L883005-05567 CAP-CSM 1000P/K 10-V 0402--X7R *** 003L211021-01388 CAP-CSM 1000P/K 10-V 0402--X7R *** 003L211021-01388 CAP-CSM 1000P/K 10-V 0402--X7R *** 003L211021-01388 C113...
  • Page 22 VR LIN TRIMMER 10K- B - 0.15W PANASONIC EVM3YSX50B14 +/-25% 026LA10311-70009 VR LIN TRIMMER 50K- B - 0.15W PANASONIC EVM3YSX50B54 +/-25% 026LA50311-70001 PCB 4L FR4- L112.5W57--T10- V4 MAIN TM832EUL L2-3:0.2MM ROHS 116L4832EU-56B42 TM832EUL/PTT/SMD/PCBA/ COBRA/EU/BLK/REV.0 A28P4030126L0006 SWITCH TACT 1P2T 250M SMD ROHS SUN RISE TM1103R25W-2500-TR 022L041103-R25W8...
  • Page 23 MAIN PCB ASSEMBLY Ref.No. Description Mfr's Part No. PCB DS FR4- L33---W8---T10- PTT REV.2 TM832USL ROHS 116L2832EU-USF28 TM832USL/MAIN/BTM/SMD/PCBA/ COBRA/US/BLK/REV.0 A28P4030214L0005 CAP-CSM 18--P/J 50-V 0603--NPO *** ROHS 003L151805-05564 CAP-CSM 18--P/J 50-V 0402-COG MURATA 003L881805-05365 CAP-CSM 18--P/J 50-V 0402-COG MURATA 003L881805-05365 CAP-CSM 10--P/J 50-V 0603-NPO *** GRM1885C1H100JA01D...
  • Page 24 PARTS LIST-CONTINUED MAIN PCB ASSEMBLY Ref.No. Description Mfr's Part No. CAP-CSM 1000P/K 10-V 0402--X7R *** 003L211021-01388 CAP-CSM 1000P/K 10-V 0402--X7R *** 003L211021-01388 CAP-CSM 1000P/K 10-V 0402--X7R *** 003L211021-01388 CAP-CSM 1000P/K 10-V 0402--X7R *** 003L211021-01388 CAP-CSM 1000P/K 10-V 0402--X7R *** 003L211021-01388 CAP-CSM 1000P/K 10-V 0402--X7R *** 003L211021-01388 CAP-CSM 1000P/K 10-V 0402--X7R ***...
  • Page 25 PARTS LIST-CONTINUED MAIN PCB ASSEMBLY Ref.No. Description Mfr's Part No. CAP-CSM 10--N/K 25-V 0402--X7R MURATA ROHS 003L211032-51364 CAP-CSM 10--N/K 25-V 0402--X7R MURATA ROHS 003L211032-51364 CAP-CSM 10--N/K 25-V 0402--X7R MURATA ROHS 003L211032-51364 CAP-CSM 10--N/K 25-V 0402--X7R MURATA ROHS 003L211032-51364 CAP-CSM 10--N/K 25-V 0402--X7R MURATA ROHS 003L211032-51364 CAP-CSM 100-N/K 16-V 0402-X7R *** 003L211041-61360...
  • Page 26 PARTS LIST-CONTINUED MAIN PCB ASSEMBLY Ref.No. Description Mfr's Part No. C135 CAP-CSM 100-N/K 16-V 0402-X7R *** 003L211041-61360 C136 CAP-CSM 1---U/Z 6.3V 0402--Y5V MURATA GRM155F50J105Z ROHS 003L201050-68366 C138 CAP-CSM 33--N/K 16-V 0402--X7R EYANG ROHS 003L213331-613H5 C140 CAP-CSM 100-N/K 16-V 0402-X7R *** 003L211041-61360 C143 CAP-CSM 220-P/J 50-V 0402-COG MURAT GMR155C1H221JA01D...
  • Page 27 PARTS LIST-CONTINUED MAIN PCB ASSEMBLY Ref.No. Description Mfr's Part No. C191 CAP-CSM 1---U/Z 6.3V 0402--Y5V MURATA GRM155F50J105Z ROHS 003L201050-68366 C192 CAP-CSM 100-N/K 16-V 0402-X7R *** 003L211041-61360 C193 CAP-CSM 100-N/K 16-V 0402-X7R *** 003L211041-61360 C194 CAP-CSM 1000P/K 10-V 0402--X7R *** 003L211021-01388 C195 CAP-CSM 10--N/K 25-V 0402--X7R MURATA ROHS 003L211032-51364...
  • Page 28 PARTS LIST-CONTINUED MAIN PCB ASSEMBLY Ref.No. Description Mfr's Part No. CHOKE--- 47----NH J 0.95R 0603 MATSUSHITA ELJRE47NJF2 006L847100-60000 CHOKE--- 47----NH J 0.95R 0603 MATSUSHITA ELJRE47NJF2 006L847100-60000 CHOKE--- 2.2---UH J 1.55R 2520 TDK NLV25T-2R2J-PF 006L822503-50004 CHOKE--- 2.2---UH J 1.55R 2520 TDK NLV25T-2R2J-PF 006L822503-50004 CHOKE--- 2.2---UH J 1.55R 2520 TDK NLV25T-2R2J-PF 006L822503-50004...
  • Page 29 PARTS LIST-CONTINUED MAIN PCB ASSEMBLY Ref.No. Description Mfr's Part No. RES-TFC 220--OHM 1/16W J 0402- *** 200 021L622009-10124 RES-TFC 220--OHM 1/16W J 0402- *** 200 021L622009-10124 RES-TFC 220--OHM 1/16W J 0402- *** 200 021L622009-10124 RES-TFC 220--OHM 1/16W J 0402- *** 200 021L622009-10124 RES-TFC 4.7K-OHM 1/16W J 0402- 200PPM ASJ CR10-472-JT 021L247019-10225...
  • Page 30 PARTS LIST-CONTINUED MAIN PCB ASSEMBLY Ref.No. Description Mfr's Part No. RES-CF- 1K---OHM 1/16W J 0402- 200PPM ASJ CR10-102-JT 021L210019-10222 RES-CF- 1K---OHM 1/16W J 0402- 200PPM ASJ CR10-103-JT 021L210019-10223 RES-CF- 1K---OHM 1/16W J 0402- 200PPM ASJ CR10-102-JT 021L210019-10222 RES-CF- 1K---OHM 1/16W J 0402- 200PPM ASJ CR10-104-JT 021L210019-10224 RES-CF- 1K---OHM 1/16W J 0402- 200PPM ASJ CR10-105-JT 021L210019-10225...
  • Page 31 PARTS LIST-CONTINUED MAIN PCB ASSEMBLY Ref.No. Description Mfr's Part No. R103 RES TFC 0.39-OHM 1/8-W J 1206- ROHS 021L6390A9-27924 R104 RES TFC 0.39-OHM 1/8-W J 1206- ROHS 021L6390A9-27924 R105 RES-CF- 10K--OHM 1/16W J 0402- 200PPM ASJ CR10-103-JT 021L210029-10220 R106 RES-TFC 33K--OHM 1/16W J 0402- *** 200 021L633029-10125 R107 RES-TFC 2.2K-OHM 1/16W J 0402- *** 200...
  • Page 32 PARTS LIST-CONTINUED MAIN PCB ASSEMBLY Ref.No. Description Mfr's Part No. R146 RES TFC 18K--OHM 1/16W J 0402- *** 200 021L618029-10129 R147 RES-CF- 4.7--OHM 1/16W J 0402- 200PPM ASJ CR10-4R7-JT 021L247089-10221 R148 RES-TFC 200K-OHM 1/16W F 0402 *** ROHS 021L620031-10324 R149 RES-TFC 100K-OHM 1/16W F 0402- *** 200 021L610031-10125 R155...
  • Page 33 SCREW MS M3.0L09 PH - + FL S/S BLK ROHS 071L130093-50001 O-RING OD6.5*ID4.5*W1.0 SIL BK TM832EUL ROHS 100L001225-012 OTHER CASING ASSEMBLY TM832EUL/OTHER CASING/E-M COMP COBRA/EU/BLK/REV.0 A28P2730103L0007 KEY VOL- TM832EUL ABS BLK 3U2X ROHS 054L004483D013 KEY SQ-- TM832EUL ABS BLK 3U2X ROHS 054L004484E016...
  • Page 34 TM832USL/FNT HSG/E-M COMP/ COBRA/US/BLK/REV.0 A28P2730201L0003 SPK FLAT 8--OHM D40-H5.2 1---W TAIHEXING TEK404P-8 OHM1W ROHS 002L240145-11004 CAB FNT MU COBRA TM832USL ABS GREY DS 022 ROHS 051L003546C017 LENS MAIN TM832EUL COBRA PMMA ROHS 055L002776C015 PLAS PLATE-- PTT MOUNT PC BLK 3U2X TM832EUL ROHS 056L006978D011 INSU SHT- NYLON D37.3 TM832EUL SPEAKER FELT...
  • Page 35 Description Mfr's Part No. SCREW M3.0*8.0mm PB IRON 067L130086-10003 CUSH RUB KE941-U 10x1.6 TE238R 089L001127-035 CHARGER PACKING MATERIAL ASSEMBLY TM832EUL/CRADLE CHG/PKG MAT'L/ COBRA/EU/BLK/REV.0 A28P1700103L0007 RATING LABEL FOR TM832EUL CHG ROHS 081L001998-010 BAG PE 165*180MM FOR NC886G CHG ROHS 088L003395-019 TM886BEUG/PKG MAT'L/CHG SCREW/ COBRA/EUR/BLACK/REV.0 886P1702300L0000 SCREW TS D3.0L23 PH - + SH S/S ROHS...

  • Page 36: Ic Lead Identification And Internal Diagram

    IC LEAD IDENTIFICATION AND INTERNAL DIAGRAM 4116 PIN FUNCTION 3. MIXER OUT 4. VCC 5. IF IN 6. BY PASS 7. FILTER OUTPUT 8. FILTER INPUT 9. AUDIO 10. DISCRIMINATOR 11. IF OUTPUT 12. RSSI 13. COMP OUTPUT 14. COMP INPUT 15.
  • Page 37 2904 PIN FUNCTION 1.A OUTPUT 2.A - INPUT 3.A +INPUT 4.GND 5.B +INPUT 6.B - INPUT 7.B OUTPUT U3-XC61FC4012MR VOUT Delay Circuitry Vref 1. VOUT 2. VSS 3. VIN...
  • Page 38 4/ 5- 324 8825 01- 090 U SIT DPLL Fin1 Fin2 OSC1 DATA OSCO 16TSSOP...
  • Page 39 U7-M38C29FFAHP60K...
  • Page 40 U7-M38C29FFAHP60K...
  • Page 41 U8-XC6204B502MR 24 16...
  • Page 42 U11-NJM2070 BIAS +INPUT +INPUT -INPUT OUTPUT -INPUT 100K OUTPUT U401-HT1621-DICE...

  • Page 43: Transistor Lead Identification

    TRANSISTOR LEAD IDENTIFICATION MMBT3904 MMBT3906 1.Gate 1 1. Base 2.Gate 2 2. Emitter 3.Drain 3. Collector 4.Source 4901 8550 2SC4097R 1.Gate 1.Base 2.Drain 2.Emitter 3.Source 3.Collector 2SK3078 Terminal No. 1.Gate 1.Drain (output) 2.Source 2.Source (GND) 3.Drain 3.Gate (input) 2SK210Y Drain Gate Source...
  • Page 44 KTC9014 Emitter Emitter Base Collector Collector Base...

  • Page 45: Voltage Chart

    VOLTAGE CHART U1 BA4116FV Rx(V) 4.78 4.20 3.45 4.81 4.38 4.39 0.64 0.60 RFIN Rx(V) 0.94 U2 NJM2904M Tx(V) 0.48 0.48 4.70 4.80 0.40 7.20 U3 XC61FC4012MR 5.00 5.00 Tx(V) Rx(V) 5.00 5.00 U4 S324 Tx(V) 4.80 1.86 1.86 1.86 1.86 1.86 1.86...
  • Page 46 VOLTAGE CHART-CONTINUED U6 SIT8825B01-R090 FIN1 OSCO OSCI Rx(V) 4.82 4.82 1.63 4.81 3.65 3.89 4.73 FIN2 Rx(V) 4.82 4.82 U8 XC6204B502MR VOUT Rx(V) 7.20 7.20 4.99 U9 AT24C16BN-SH-T Tx(V) 4.98 4.99 U11 NJM2070M Rx(V) 0.60 3.26 7.16...
  • Page 47 VOLTAGE CHART-CONTINUED TRANSISTOR Q1 2SC4901YK Q2 2SC4901YK Q3 2SC4901YK Q4 2SC4901YK 0.70 0.80 0.25 4.54 0.74 3.76 Tx(V) Rx(V) 0.71 Q5 2SC4901YK Q6 RD07MVS1 Q7 2SC4901YK Q9 MMBT3906LT1 Tx(V) 2.30 6.80 Rx(V) 0.70 3.90 0.78 2.32 3.40 4.10 4.02 Q8 3SK318 Tx(V) Rx(V) 1.57...
  • Page 48 VOLTAGE CHART-CONTINUED Q23 2SC4097R Q27 MMBT3904LT1 Moto(on) 4.50 3.20 6.80 0.65 Mute Q26 MMBT3906LT1 3.48 4.10 4.10 Tx(V) Rx(V) CHARGER Q01 2SB772-P Q2 KTC9014C Q3 KTC9014C Charging 10.00 12.00 8.20 0.70 11.00 Standby 12.00 12.00 0.70 0.70...

  • Page 49: Schematic Diagram

    SCHEMATIC DIAGRAM MAIN CLONE MUTE C174 C147 ALERT OSCO DATA OSCI BEEP / CALL Fin2 Fin1 RSSI MUTE BUSY SCLK 2.2uH ATT - 2.2uH 100K ATIS1 ATIS1 ATIS2 ATIS2 CNVss ATIS3 ATIS3 4.7nH ATIS4 RESET RESET ATIS4 & Xout 9.828M 1050HZ ATIS / Hz...
  • Page 50 SCHEMATIC DIAGRAM-LCD MISO MOSI DATA INT /...
  • Page 51 SCHEMATIC DIAGRAM-CHARGER...

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