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SECTION 3

DISASEMBLY INSTRUCTION

3 - 1

A

B

B

MAIN unit

RF unit

C

D

E

G

F

REMOVING THE REAR PANEL

1

Unscrew 1 screw 

A

, and 4 screws 

B

.

2

Remove the rear panel in the direction of the arrow.

REMOVING THE RF UNIT

1

Remove 1 knob 

C

, and unscrew 1 nut 

D

.

2

Then remove the RF unit.

REMOVING THE MAIN UNIT

1

Unscrew 2 screws, 

E

.

2

Remove the PTT rubber, 

F

.

3

Unsolder 2 points, 

G

, and remove the MAIN unit.

Summary of Contents for PMR446

Page 1: ...SERVICE MANUAL PMR446 FM TRANSCEIVER...

Page 2: ...M2x6 ZK IC 446S Chassis 10 pieces Addresses are provided on the inside back cover for your convenience 1 Make sure a problem is internal before disassembling the transceiver 2 DO NOT open the transce...

Page 3: ...SUPPLY CIRCUITS 4 3 4 5 PORT ALLOCATIONS 4 3 SECTION 5 ADJUSTMENT PROCEDURES 5 1 PREPARATION 5 1 5 2 PLL AND TRANSMITTER ADJUSTMENTS 5 2 5 3 RECEIVER ADJUSTMENT 5 3 SECTION 6 PARTS LIST SECTION 7 MECH...

Page 4: ...iving system Double conversion superheterodyne Intermediate frequency 1st 21 7 MHz 2nd 450 kHz Sensitivity 12 dB SINAD Less than 0 25 V 12 dB V Adjcent chnnel selectivity 55 dB Spurious response 65 dB...

Page 5: ...amplifier IC9 NJM2070M EEPROM IC3 AT24C02N CPU IC1 PD753036GK 3 Regurator IC6 S 81230SG TOP VIEW BOTTOM VIEW 1st mixer Q2 3SK284 Reference oscilletor X1 CR 669 21 25MHz PLL IC IC1 PD3140GS TOP VIEW BO...

Page 6: ...L 1 Unscrew 1 screw A and 4 screws B 2 Remove the rear panel in the direction of the arrow REMOVING THE RF UNIT 1 Remove 1 knob C and unscrew 1 nut D 2 Then remove the RF unit REMOVING THE MAIN UNIT 1...

Page 7: ...applied to the 2nd mixer circuit 4 1 4 2ND MIXER AND DEMODULATOR CIRCUITS RF UNIT The 2nd mixer circuit converts the 1st IF signal into a 2nd IF signal A double conversion superheterodyne system whic...

Page 8: ...cuit modulates the VCO oscillating signal RF signal using the microphone AF signals The filtered audio signals from the MAIN unit are passed through the deviation adjustment pot R50 and are then appli...

Page 9: ...EPROM IC3 Outputs data signals to the EEPROM IC3 Output port for power save function applied to VCO regurator circuit RF unit Q13 Q14 D8 D9 Outputs the R 3 regulator control sig nal Q25 D4 Outputs the...

Page 10: ...C millivoltmeter External speaker Attenuator GRADE AND RANGE Frequency range 300 3000 Hz Measuring range 1 500 mV Frequency range 0 1 600 MHz Output level 0 1 V 32 mV 127 to 17 dBm Frequency range DC...

Page 11: ...or to the MIC jack and set as 1 kHz 100 mV rms Set an FM deviation meter as HPF OFF LPF 20 kHz or 15 kHz De emphasis OFF Detector P P 2 Transmitting Set group No OFF Set an audio generator output leve...

Page 12: ...UNIT LOCATION Audio signal disappears 1 2 Operating channel Ch 04 Connect an SSG to J1 on the RF unit and set as Frequency 446 04375 MHz Level 0 14 V 124 dBm Modulation OFF Receiving Set an SSG as Le...

Page 13: ...RJ3GEYJ 104 V 100 k R63 7030003530 S RESISTOR ERJ3GEYJ 562 V 5 6 k R64 7030003590 S RESISTOR ERJ3GEYJ 183 V 18 k R65 7030003590 S RESISTOR ERJ3GEYJ 183 V 18 k R66 7030003590 S RESISTOR ERJ3GEYJ 183 V...

Page 14: ...ESISTOR ERJ3GEYJ 333 V 33 k RF UNIT MAIN UNIT S Surface mount C34 4030006880 S CERAMIC C1608 JB 1H 472K T A C35 4030011600 S CERAMIC C1608 JB 1C 104KT N C36 4030006860 S CERAMIC C1608 JB 1H 102K T A C...

Page 15: ...006980 S CERAMIC C1608 CH 1H 070D T A C31 4030006980 S CERAMIC C1608 CH 1H 070D T A C32 4030006970 S CERAMIC C1608 CH 1H 060D T A C35 4030006860 S CERAMIC C1608 JB 1H 102K T A C36 4030006990 S CERAMIC...

Page 16: ...30045220 2045 BATT seal 1 MP14 8930046280 2045 ANT termainal 1 MP15 8930045350 2045 A terminal 1 MP16 8930045360 2045 B terminal 1 MP17 8930045370 2045 C terminal 2 MP19 8930045740 2045 sheet 1 MP20 8...

Page 17: ...RF RF UNIT MP1 C SP1 C MP10 C MP12 C EP1 M DS2 M MP7 C MP5 C MAIN unit MP20 C MP25 C MP4 RF MP14 C MP17 C MP2 RF MP16 C MP23 C MP5 RF MP11 C MP13 C MP4 C MP2 C MP15 C MP25 C MP9 C MP8 C RF unit MP24...

Page 18: ...ol K1 3SK284 Symbol U1 2SC4215 O Symbol QO 2SC4226 T2 R25 Symbol R25 2SC4228 T2 R44 Symbol R44 2SC5006 T1 Symbol 24 2SA1586 GR Symbol SG 2SB798 T2 DK Symbol DK 2SC3356 R24 T2B Symbol R24 2SC4081 T107S...

Page 19: ...C74 R49 R200 R201 R114 R115 R119 R204 W3 R98 C53 C60 C81 R74 R76 C63 R23 R80 R78 C88 W7 C90 C62 R102 R12 C35 C34 R10 C25 C3 R9 R31 R202 R118 R110 R45 R36 C36 C31 R42 R41 C32 R38 R46 C7 R13 C4 C79 R50...

Page 20: ...C85 C99 R2 R30 C1 R39 C73 R40 R64 W2 R5 R53 C24 C98 C93 R52 R51 C83 Q2 Q12 Q1 Q29 R32 R35 C28 C91 C10 R14 C51 R62 R103 R101 R117 R105 R203 R108 R100 R96 R57 C26 R34 C40 R95 C11 R33 C27 R7 R6 C29 C6 I...

Page 21: ...D8 C86 C48 C61 C69 R10 W5 L15 R45 C16 C26 C23 R27 R64 R302 R215 R205 D103 C206 R209 R202 C202 W202 L205 C207 C208 L201 W201 C201 C203 C204 L202 R213 R305 L208 R313 R306 C67 R12 C70 R65 R93 R62 C87 R1...

Page 22: ...0 R206 Q12 C84 Q7 C56 Q6 C51 D4 D5 L13 L12 C32 R70 J1 FI3 FI2 B5421B R72 C6 L3 R7 R75 R76 Q16 R74 C93 C92 C91 D102 D101 C210 C209 R207 C205 R301 L206 R83 C5 C95 R73 R16 R25 C7 L4 R30 R29 C20 L11 C53 C...

Page 23: ...4EU LPF IDC 3V IC2A NJM2100M Q6 2SK1829 MIC MUTE IC2B NJM2100M Q23 2SJ144 R58 AF VOL VOL MUTE MC1 KUC3523 PTT SENSE MIC SW MIC R 3 CURRENT AMP R 3 T 3 3V CURRENT AMP Q25 UMZ2N D4 1SS355 3V to LOGIC 3...

Page 24: ...COM0 COM1 COM2 COM0 COM1 COM2 DS2 LD BU10503J R65 18 k R66 18 k R64 18 k 3 V SHIFT VOL CK DATA STB AF SENS SQL MOD PSC R 3 T 3 BATT 1 2 3 4 5 6 7 8 9 10 11 12 13 14 J4 8 IC2a NJM2100M R30 15 k C73 0...

Page 25: ...4 6 P T 3 C23 7 P R202 22 k D2 MA77 C70 470 P D1 MA77 R12 1 k R208 1 k R37 22 k C102 2 P C88 10 C16 470 P R305 3 9 k C62 0 033 R45 8 2 k C68 0 68 R306 8 2 k R10 8 2 k C17 0 033 C61 5 P R88 4 7 k R313...

Page 26: ...om france com Crta de Gracia a Manresa Km 14 750 08190 Sant Cugat del Valles Barcelona SPAIN Phone 93 590 26 70 Fax 93 589 04 46 URL http www icomspain com Corporate Headquarters 2380 116th Avenue N E...

Page 27: ...COVER 99 12 18 8 39 AM Page 1...

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