Kenwood TM-271A Service Manual Download Page 28

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COM3

COM2

COM3

COM0

SEG31

SEG30

SEG29

SEG28

SEG27

SEG26

SEG25

SEG24

SEG23

SEG22

SEG21

SEG20

SEG19

SEG18

SEG17

SEG16

SEG15

SEG14

SEG13

SEG12

SEG11

SEG10

SEG9

SEG8

SEG7

MIC JACK

D19

D20

D21

CALL

VFO

D22

D23

D25

D26

D27

D28

D29

VR1

POWER/VOL

C24

C27

C30

C31

C32

C33

C36

C38

C39

PTT

MIC

MBL

GND

HOOK

C40

R55

D31

IC3

R21

R22

R23

R25

R46

R51

R52

R53

CP1

C15

C16

C19

LCD

TM-271A/271E

PC BOARD

DISPLAY UNIT (X54-3450-10) Component side view (J72-0905-09)

DISPLAY UNIT (X54-3450-10) Foil side view (J72-0905-09)

Summary of Contents for TM-271A

Page 1: ...ION 27 PC BOARD DISPLAY UNIT X54 3450 10 28 TX RX UNIT X57 685X XX 30 SCHEMATIC DIAGRAM 34 BLOCK DIAGRAM 38 LEVEL DIAGRAM 40 SPECIFICATION BACK COVER CONTENTS Microphone T91 0624 05 Cabinet A01 2193 01 Panel assy A62 1088 03 Knob Encoder K29 9293 03 Knob Volume K29 9292 03 Key top K29 9291 01 Microphone T91 0641 05 Cabinet A01 2193 01 Panel assy A62 1088 03 Knob Encoder K29 9293 03 Knob Volume K29...

Page 2: ...SYSTEM PLL VCO 16 8MHz 50 4MHz ANT RX TX SP MIC 1 2 Fig 1 Frequency configuration IF Amplifier The first IF signal is amplified by Q351 and then goes to IC301 FM processing IC The signal is heterodyned again with a second local oscillator signal within IC301 to create a 450kHz second IF signal The second IF signal is then fed through a 450kHz ceramic filter Wide CF301 Narrow CF302 to further elimi...

Page 3: ...1 IC161 W NO EVOL2 AF PA IC252 SP IF IC IC301 Q301 NOISE AMP D301 IC301 IC101 AFO RSSI DET CPU IF SYSTEM SQIN RSSI Fig 3 Wide Narrow switching circuit Fig 4 AF signal system Fig 5 Squelch circuit PLL Frequency Synthesizer The PLL circuit generates the first local oscillator signal for reception and the RF signal for transmission PLL The frequency step of the PLL circuit is 5 or 6 25kHz A 16 8MHz r...

Page 4: ...e low pass filter removes unwanted high frequency harmonic com ponents and the resulting signal is transmitted through the antenna terminal See Fig 8 APC Circuit The automatic transmission power control APC circuit detects part of a final amplifier output with a diode D606 D607 and applies a voltage to IC501 IC501 compares the APC control voltage PC generated by the D A converter IC161 and DC ampl...

Page 5: ...LCD driver The LCD driver monitors the status of the KI1 to KI3 and KS1 to KS2 ports If the state of one of the ports changes the LCD driver assumes that the key at the matrix point corre sponding to that port has been pressed Encode The DCS and CTCSS signals are output from QT DQT of the CPU IC101 and summed with the external pin DI line by the summing amplifier IC203 and the resulting signal goe...

Page 6: ...hen CPU send to EEPROM IC66 the backup data and go into STOP mode This circuit has an overvoltage protection circuit If a DC voltage of 18V or higher is applied to the base of Q61 this voltage turns Q61 on and will set to high on CPU port 18 INT Then CPU send to EEPROM IC66 the backup data and go into stop mode See Fig 16 IC101 CPU DTMF IN W NO EVOL2 95 Q71 SW Q31 SW Q32 SW Q61 SW IC33 AVR D61 D62...

Page 7: ...lways output whether the squelch is open or closed PR1 is the 1200bps data communications reception out put It outputs the FM detection circuit output through an AF filter IC251 Output is controlled with the mute switch Q252 according to whether squelch is open or closed See Fig 17 Squelch Signal Output Circuit The squelch circuits is input to the TNC to prevents con flicts from occurring between ...

Page 8: ... mute 51 SPM O Speaker mute 52 AMPSW O AF AMP switch Pin No Name I O Function 53 DT O Common data 54 CK O Common clock 55 NC I 56 DST1 I Destination 1 57 59 DST2 DST4 I Destination 2 4 60 VCC 5V 61 NC I 62 VSS GND 63 ADJ I For adjustment mode 64 NARROW O Wide Narrow 2 65 WIDE O Wide Narow 66 67 NC I 68 LCDCL O Clock for LCD 69 LCDCE O Chip enable for LCD 70 LCDDO O Output data to LCD 71 LCDDI I In...

Page 9: ...ile SPM is H Q255 Transistor AF mute Active while AMPSW is H Q301 Transistor Noise amplifier SQL amplifier Ref No Parts name Description Q302 Transistor Buffer amplifier 16 8MHz 3rd over tone Q351 Transistor IF amplifier Q352 FET Mixer Q353 FET RF amplifier LNA Q354 Transistor PC TV switch Q402 403 Transistor Charge pump Q404 Transistor RF amplifier PLL F in Q405 FET RX VCO Q406 FET TX VCO Q407 FE...

Page 10: ... 1544 01 PACKING SHIELDING COVER 31 1A G53 1548 02 GASKET 33 2C 1D H12 3112 05 PACKING FIXTURE 34 3D H13 1190 02 CARTON BOARD 36 1D H25 2341 04 PROTECTION BAG 37 2D H52 1995 12 ITEM CARTON CASE K M2 37 2D H52 2027 02 ITEM CARTON CASE M3 37 2D H52 2028 02 ITEM CARTON CASE M4 37 2D H52 2029 12 ITEM CARTON CASE E 39 3C J19 1584 05 MIC HOLDER ACCESSORY 40 3D J29 0662 03 BRACKET ACCESSORY 42 3A K29 929...

Page 11: ...C206 CK73GB1H102K CHIP C 1000PF K M4 C206 CK73GB1H681K CHIP C 680PF K E C207 CK73GB1C223K CHIP C 0 022UF K K M2 M3 C207 CK73GB1C223K CHIP C 0 022UF K M4 C207 CK73GB1C393K CHIP C 0 039UF K E C208 CK73GB1H103K CHIP C 0 010UF K C209 CC73GCH1H680J CHIP C 68PF J C210 CK73GB1C104K CHIP C 0 10UF K C211 CK73GB1H821K CHIP C 820PF K C212 CK73GB1H122K CHIP C 1200PF K C213 CK73GB1H332K CHIP C 3300PF K C214 CC...

Page 12: ...CK73GB1H103K CHIP C 0 010UF K C414 CK73GB1C104K CHIP C 0 10UF K C416 418 CK73GB1H102K CHIP C 1000PF K C421 422 CK73GB1H471K CHIP C 470PF K C423 C92 0555 05 CHIP TAN 0 047UF 35WV C424 C92 0004 05 CHIP TAN 1 0UF 16WV C425 C92 0001 05 CHIP C 0 1UF 35WV C426 CC73GCH1H300J CHIP C 30PF J C427 CC73GCH1H080B CHIP C 8 0PF B C428 CK73GB1H471K CHIP C 470PF K C429 CC73GCH1H010B CHIP C 1 0PF B C430 CC73GCH1H4R...

Page 13: ...H L413 L40 4778 67 SMALL FIXED INDUCTOR 47NH L414 415 L40 2702 86 SMALL FIXED INDUCTOR 27UH L416 417 L92 0443 05 FERRITE CHIP L418 L41 3375 06 SMALL FIXED INDUCTOR L419 L41 1085 06 SMALL FIXED INDUCTOR L420 L41 1585 06 SMALL FIXED INDUCTOR L421 L41 1085 06 SMALL FIXED INDUCTOR L422 L40 5675 92 SMALL FIXED INDUCTOR 56NH L423 L92 0443 05 FERRITE CHIP L501 502 L41 6875 08 SMALL FIXED INDUCTOR L503 50...

Page 14: ...73GH1J913D CHIP R 91K D 1 16W R264 RK73GH1J124D CHIP R 120K D 1 16W R265 RK73GH1J562D CHIP R 5 6K D 1 16W R266 RK73GB1J562J CHIP R 5 6K J 1 16W R268 RK73GB1J102J CHIP R 1 0K J 1 16W R269 RK73GB1J393J CHIP R 39K J 1 16W R271 RK73GB1J332J CHIP R 3 3K J 1 16W R272 RK73GB1J392J CHIP R 3 9K J 1 16W R273 RK73GB1J123J CHIP R 12K J 1 16W R274 275 RK73GB1J153J CHIP R 15K J 1 16W R276 RK73GB1J473J CHIP R 47...

Page 15: ...CHIP R 2 2K J 1 10W R514 R92 1217 05 CHIP R 0 OHM R516 R92 0670 05 CHIP R 0 OHM R518 RK73EB2B330J CHIP R 33 J 1 8W R519 RK73GB1J333J CHIP R 33K J 1 16W R520 RK73GB1J183J CHIP R 18K J 1 16W R521 RK73GB1J101J CHIP R 100 J 1 16W R522 RK73EB2B331J CHIP R 330 J 1 8W R523 RK73GB1J393J CHIP R 39K J 1 16W R524 R92 1215 05 CHIP R 470 J 1 2W R525 RK73GB1J563J CHIP R 56K J 1 16W R526 R92 1261 05 CHIP R 150 J...

Page 16: ...403 2SC4738 GR TRANSISTOR Q404 2SC4649 N P TRANSISTOR Q405 406 2SK508NV K52 FET Q407 2SJ347 FET Q408 KRX102U TRANSISTOR Q410 2SC5108 Y TRANSISTOR Q411 2SC4649 N P TRANSISTOR Q440 2SC2412K TRANSISTOR Q501 502 2SC3357 TRANSISTOR Q503 PD55003TR DRIVE FET Q504 2B RD70HVF1 01 FINAL FET TH97 98 NCP18WF104J03 THERMISTOR TH301 NCP18WF104J03 THERMISTOR Ref No Address Parts No Description Desti nation New p...

Page 17: ... Dx8 12 13 14 29 Ax2 A Cx12 26 23 13 14 IC252 Q504 25 27 9 8 Cx2 Cx2 6 701 S No label 702 Standard label K 700 Caution label 703 Sticker M3 28 44 43 48 15 42 24 24 Bx2 16 103 101 104 102 TX RX unit Display unit A M2 6 x 8 N67 2608 46 B M2 x 10 BLK N80 2010 45 C M2 6 x 6 Br Tap N87 2606 46 D M2 6 x 14 Br Tap N87 2614 46 ...

Page 18: ...M3 M4 46 Screw set N99 0395 05 49 Microphone T91 0624 05 M2 M4 704 Pamphlet 705 Warranty card 36 Protection bag H25 2341 04 36 Protection bag H25 2341 04 33 Packing fixture H12 3112 05 33 Packing fixture H12 3112 05 34 Carton board H13 1190 02 40 Bracket J29 0662 03 39 MIC holder J19 1584 05 37 Item carton case H52 1995 12 K M2 H52 2027 02 M3 H52 2028 02 M4 H52 2029 12 E 50 Microphone T91 0641 05 ...

Page 19: ...essage VFO Reset This resets the transceiver parameters excluding the DTMF Memory the Memory channel contents and the Call channel contents There are two methods available for reset ting the transceiver Note Menu No 7 P VFO and Menu No 10 OFFSET re turn to the factory default values VFO Reset Method 1 1 With the transceiver power OFF press VFO Power The VFO reset confirmation message appears 2 Pre...

Page 20: ...item dis play returns t Moves the adjustment item forward If it is operated when a frequency is displayed the adjustment item dis play returns y If it is pressed before determining the adjustment value the adjustment value of the Adjustment item returns to its original value u Not used in Adjustment Mode Note If Max Power for transmission is low check the DC cable If the DC cable connector has poo...

Page 21: ...ppear 136 10 136 05 CTCSS 88 5Hz Center 155 10 155 05 High 173 90 173 95 CTCSS Fine Deviation Narrow Center CT and N icon appear 155 10 155 05 DCS Fine Deviation Low DCS icon appear 136 10 136 05 DCS 023N Center 155 10 155 05 High 173 90 173 95 DCS Fine Deviation Narrow Center DCS and N icons appear 155 10 155 05 DTMF Fine Deviation Center 155 10 155 05 DTMF 9 DTMF Fine Deviation Narrow Center N i...

Page 22: ...m or less 7 Ammeter 20A 8 AF Volt Meter Frequency Range 50Hz to 10kHz AF VTVM Voltage Range 1mV to 3V 9 Audio Generator AG Frequency Range 20Hz to 20kHz or more Output 0 to 1V 10 Distortion Meter Capability 3 or less at 1kHz Input Level 50mV to 10Vrms 11 8Ω Dummy Load Approx 8Ω 10W or more 12 Regulated Power Supply 13 8V approx 20A adjustable from 9 to 17V Useful if ammeter requipped 13 Spectrum A...

Page 23: ...ing the shield cover as below Fuse To mount the fuse the cable terminal direction must be as follow Except the E type models Locator Speaker cable This side up This side up Cable terminal Cable terminal Fuse Pin 1 marker Part name label face down IC252 TX RX UNIT Component side ANT TC401 TC402 L301 BPF B E TX RX unit Foil side F501 VR601 Q503 Q504 R516 R518 R524 IC252 GND PR9 PR1 PKS SQC PKD 5M CN...

Page 24: ...dition Test equipment Terminal Parts Method Specifications Remarks Measurement Adjustment Transmitter Section 1 Frequency 1 CH TX center Frequency counter ANT Encoder Adjust to center frequency Within 50Hz 2 Transmit knob 2 Maximum 1 CH TX high Power meter VR601 55W 1W power 2 Adjustment HEX value FF alignment 3 Transmit 3 High 1 CH TX low Encoder Low 50W 1 0W power CH TX low knob Low 60W CH TX ce...

Page 25: ...or power to be within the range of 0 3W 0 6W If power found is less than 0 3W check the circuit before the Drive FET 6 MAX 1 CH TX low Wide Modulation analyzer ANT Encoder 4 0kHz Wide 100Hz Wide deviation CH TX center Wide Narrow or Linear detector MIC knob 2 0kHz Narrow 50Hz Narrow CH TX high Wide LPF 15kHz According to the large 2 AG 1kHz 50mV Oscilloscope 3 Transmit AG AF V M 7 MIC 1 CH TX cent...

Page 26: ...z Dev 3 0kHz Wide Dev 1 5kHz Narrow 4 RSSI 1 CH RX center Wide Push RSSI value writing is per writing 2 SSG output 53dBm 501µV encoder formed by the Squelch Mod 1kHz knob open item center wide Dev 3 0kHz SSG output level is changed and adjusted after SQ adjustment This adjustment should not turn the encoder 5 S meter 1 CH RX center Wide S1 2 SSG output 118dBm 0 28µV Mod 1kHz Dev 3 0kHz 6 S meter 1...

Page 27: ...nd 2 SQC Squelch Signal 3 PKS Transmission Control 4 PR1 1200bps Receive Data 5 PR9 9600bps Receive Data 6 GND Ground 7 PKD Transmission Modulation CN No Pin No Name Function CN5 1 INT SP Internal speaker 2 GND Ground DISLAY UNIT X54 3450 10 CN No Pin No Name Function CN1 1 ENC A Encoder A 2 CM Microphone Key Check 3 ENC B Encoder B 4 MIC KEY Microphone Key 5 DI Data Out from LCD 6 CE Chip Enable ...

Page 28: ...8 SEG7 S G D3 J1 MIC JACK D19 D20 D21 CALL VFO MR D22 D23 D25 D26 D27 D28 D29 VR1 POWER VOL C24 C27 C30 C31 C32 C33 C36 C38 C39 8C 8C PTT PTT MIC MIC CM CM MBL MBL GND GND ME ME HOOK HOOK C40 R55 C4 L1 D31 IC3 1 16 17 32 33 48 49 64 R21 R22 R23 R25 R46 R51 R52 R53 CP1 C15 C16 C19 LCD 28 TM 271A 271E PC BOARD DISPLAY UNIT X54 3450 10 Component side view J72 0905 09 DISPLAY UNIT X54 3450 10 Foil sid...

Page 29: ...R54 CN1 1 18 ENCA CM ENCB MIC KEY DI CE CL DO 5C 8C VOL POWER RXD BRI PTT GND ME MIC 29 Component side Foil side Layer 1 Layer 2 Component side Foil side Layer 1 Layer 2 DISPLAY UNIT X54 3450 10 Foil side view J72 0905 09 DISPLAY UNIT X54 3450 10 Component side view J72 0905 09 PC BOARD TM 271A 271E Ref No Address D2 6F D3 6J D4 5O D19 4G D20 4P D21 4E D22 4I D23 4J D24 4K D25 3G D26 3F D27 3E D28...

Page 30: ...0 R55 Q10 Q12 1 2 3 5 C4 L1 D31 IC3 1 16 17 32 33 48 49 64 R10 R21 R22 R23 R25 R26 Q6 Q9 B C E R8 R41 R42 R43 R44 R45 R46 R49 R50 R51 R52 R53 R54 CN1 CP1 C15 C16 C19 LCD 1 18 ENCA CM ENCB MIC KEY DI CE CL DO 5C 8C VOL POWER RXD BRI PTT GND ME MIC 28 29 TM 271A 271E PC BOARD Component side Foil side Layer 1 Layer 2 Component side Foil side Layer 1 Layer 2 DISPLAY UNIT X54 3450 10 Component side vie...

Page 31: ...4 5 L503 L504 L505 IC401 D251 R101 R105 R106 R118 R119 E SP R120 R121 R122 R125 R516 R518 R519 R520 R521 R523 R524 R525 R527 R5 R529 R R151 R152 C514 C516 C517 C518 C519 C522 C525 C527 C528 C529 R35 R1 R36 R2 R37 R3 C530 C531 C533 C536 C151 C152 C559 Q402 Q403 C560 L201 D503 L404 R81 R82 IC252 1 10 IC5 5 8 CN1 CN2 CN5 Q252 Q253 D S G D S G Q254 Q255 C10 1 17 18 2 CM MIC KEY CE DO 8C POWER BRI GND ...

Page 32: ...H301 C305 R349 C310 C311 C312 C313 C314 R350 C315 R351 C316 R352 R353 C317 C318 R354 C319 R355 R161 R162 R164 C128 R165 R166 C321 C322 C323 C324 C525 R379 C536 C541 C542 C350 C351 C545 C546 C353 C354 C161 C355 C549 C162 C356 C163 C164 Q201 C165 C550 C552 C553 C554 C555 D302 D303 C559 C560 L401 L403 L404 C574 C576 C389 IC501 1 4 5 8 TH97 TH98 R203 R204 R205 R206 R207 R208 R209 TEMP1 PC 8T BPF AFV 8...

Page 33: ...532 C303 R533 C304 TH301 C305 R151 R152 R349 C310 C311 C312 C313 C314 R350 C315 R351 C316 R352 R353 C317 C318 R354 C319 R355 R161 R162 R164 C128 R165 R166 C514 C321 C322 C516 C323 C517 C324 C518 C519 C522 C525 C527 C528 C529 R35 R1 R36 R2 R37 R3 C530 R379 C531 C533 C536 C151 C152 C541 C542 C350 C351 C545 C546 C353 C354 C161 C355 C549 C162 C356 C163 C164 Q201 C165 C550 C552 C553 C554 C555 D302 D303...

Page 34: ...PF L352 R308 L354 L355 R309 L356 L357 R501 IC251 1 7 8 14 R502 R503 R504 R310 R505 R506 R507 R509 R510 R325 R526 C301 C302 C306 C307 C308 C309 C501 C502 C503 C504 C505 C506 C507 C509 R356 R358 R359 C511 R360 R361 XF351 C326 R362 R363 R364 R365 R366 R367 R368 R369 R370 R371 R372 R373 R374 R375 R376 C357 C358 C359 C360 C361 D301 C362 C556 C363 C557 C544 C543 C364 C558 C366 C367 C368 Q404 C369 Q405 G...

Page 35: ...6 G S D D502 R70 0 IC101 L405 L406 L407 L408 L411 L412 R86 L413 R87 L414 5 L416 R91 R92 R93 R94 X86 C14 J72 0906 09 1 25 26 50 51 75 76 100 B E O G I I O G 33 PC BOARD TM 271A 271E Ref No Address IC31 12Q IC32 13O IC34 13M IC35 13L IC66 11L IC101 11N IC251 12B IC301 12E IC402 13G Q31 5P Q32 4P Q33 12P Q34 12P Q61 4P Q86 10N Q87 10N Q251 11B Q301 13E Q352 10F Q353 10B Q404 12I Q405 12I Q406 13J Q40...

Page 36: ...3 C515 R360 R361 XF351 C326 R362 R363 R364 R365 R366 R367 R368 R369 C526 R370 R31 R371 R32 R372 R373 R33 R374 R34 R375 R376 R4 R38 R5 R39 R6 R7 R8 R40 R41 C357 C358 C359 C360 C361 D301 C362 C556 C363 C557 C544 C543 C364 C558 R61 C366 R62 C367 R63 C368 Q404 C369 Q405 G S D Q406 G S D Q407 G S D Q408 1 2 3 5 D501 D502 C370 C371 C372 C373 R70 Q410 C374 Q411 IC101 C375 C376 C377 C378 C379 L405 L406 L4...

Page 37: ... 560 PKD PKD 5C R93 6 8k R94 10k TH98 100k C97 1000p TH97 100k C98 1000p C216 39p IC161 M62363FP 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 R222 10k IC203 BA10324AFV VCC VEE C209 68p C165 1u X401 L77 1944 05 R406 10k C475 1000p C476 1000p C473 1000p C400 0 1u L406 270n L407 270n C426 30p L409 27u L408 33n C427 8p L410 27u R423 220 C429 1p R429 270 L411 270n C434 150p L413 47n C...

Page 38: ...82 SBC 83 NC 84 NC 85 NC 86 CM 87 MICKEY2 88 MICKEY 89 VOL 90 TEMP2 91 TEMP1 92 RSSI 93 SQIN 94 AVSS 95 DTMF IN 96 VREF 97 AVCC 98 NC NC NC 74 73 R124 47k R92 1k R91 1k 87 R127 47k 88 89 2SC2412K Q302 C321 68p C474 1000p SQC PKS PR1 5M 68 R125 47k R119 R120 R122 0 R121 R246 150k R247 120k R248 5 6K C249 4 7u6 3 2SC5488 Q351 R355 470 C355 18p C354 4 5p C356 3p R358 220 R361 180 C367 150p R363 330k ...

Page 39: ...8C C309 0 022u C283 1000p C37 1000p R303 22k IC501 TA75W01FU 1 2 3 4 VEE 5 6 7 8 VCC D605 XB15A709 C261 0 01u R309 3 3k R262 18k C256 0 018u R311 33k C607 2p C303 4700p R260 220k C30 1000p C528 220p R32 470 C264 0 033u R280 390 C555 5p R4 1k R2 100 R3 100 CN1 R7 1k R5 1k R8 1k R6 1k C13 470p C14 470p C10 1000p C15 470p R1 0 D3 DA221 D2 DA221 D4 DA221 D1 DA221 8C 5C 5M 88 R522 330 R523 39k C533 100...

Page 40: ...INATION SEG1 LCD B38 0885 05 SEG17 SEG27 SEG29 SEG4 SEG26 SEG31 SEG5 SEG14 SEG18 SEG19 VARIABLE SEG8 SEG12 SEG2 SEG20 LCD ILLUMINATION DISPLAY UNIT X54 3450 10 SEG22 MR SEG0 SEG16 COM0 SEG6 SEG28 SEG25 SEG30 ENCODER LCD CONTROLLER KEY BACKLIT SWITCH DIMMER FUNCTION SWITCH LCD BACKLIT D2 4 LCD BACKLIT SWITCH DC SWITCH KEY BACKLIT D19 30 MHz MENU ADJUASTMENT ON OFF VOLUME ADJUASTMENT 144 148MHz 144 ...

Page 41: ...2 O I 3 VSS 4 CONT 5 VDD C222 0 1u R224 560 PKD PKD 5C R124 47k R93 6 8k R92 1k R94 10k R91 1k TH98 100k C97 1000p TH97 100k C98 1000p 87 R127 47k 88 89 C216 39p IC161 M62363FP 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 R222 10k IC203 BA10324AFV VCC VEE C209 68p C165 1u X401 L77 1944 05 R406 10k 2SC2412K Q302 C321 68p 8C 5C 5M 88 C475 1000p C476 1000p C473 1000p C400 0 1u L406 ...

Page 42: ... 8 8TC BRI SQIN 8C CM SPLATTER FILTER 8C 8C MIC KEY MIC IDC Q404 2SC4649 N P 16 8MHz MIC PTT TXD DO ENCB KI3 ME Q407 2SJ347 IC401 MB15A02 LD DT VOL T CV 5C Q402 2SA1832 GR CL KI2 DTM Q10 KRA225S 5C Q6 KRC102S V PLLE DISPLAY UNIT X54 3450 10 Q 2SK50 MICMT D19 30 B30 2205 05 LCD BACK LIGHT Q9 2SB1132 Q R Q12 UMG3N SW MBL BRI IC3 LCD DRIVER LC75854W LC75854W CL CE DI COM0 3 SEG0 31 MBL DO LCD GND ME ...

Page 43: ...W EEPROM Q252 253 2SK3019 8R RESET NARROW D A CONV IC33 NJM78L05UA AVR IC161 M62363FP 7 8 3FP BPF Q36 KRC102S Q254 DTC363EU IC161 M62363FP 2 8 8T Q406 2SK508NV K52 IC35 BD4740G 5C RESET X86 IC161 M62363FP 5 8 6 8 IC161 M62363FP 1 8 IC34 BD4732G DTMF BEEP 8TC SQIN Q32 KRC102S SBC Q251 2SC2412K PTT FINAL AMP 8C SPM MICMT SIGNAL Q34 KRC102S 8T DRIVE AMP SB B IF DEMODULATOR AF PA AFM SW CPU IC101 3062...

Page 44: ...o make measurements in the AF section connect the AC level meter AG is set so that MIC input becomes 3kHz 1 5kHz Wide Narrow DEV at 1kHz MOD D CF1 CF2 450kHz 7 IC203 TX RX Unit S IC301 5 49 95MHz 9 IC201 G1 20 1 Center Frequency W 124 0dBm N 123 5dBm W 119 5dBm N 119 0dBm W 104 7dBm N 103 7dBm W 103 9dBm N 103 4dBm W 0 75Vrms N 0 36Vrms W 0 30Vrms N 0 18Vrms W 112 3dBm N 111 5dBm W 92 1dBm N 90 7d...

Page 45: ...r a 0 64V 8Ω by the front panel AF VOL control Q406 vel meter 12dB SINAD TX RX Unit Q410 1 11 Q411 FINAL Amp Q503 2 D409 TX RX Unit S IC402 Audio Frequency Q501 D TX RX Unit VCO CF1 CF2 450kHz Q502 G IC301 D602 G ANT 5 3dBm 10dBm 4 8dBm 12 5dBm 26 5dBm 8 8dBm 60W W 85 0dBm N 84 5dBm W N 0 33Vrms W N 0 32Vrms W N 0 26Vrms W N 0 30Vrms W N 0 31Vrms W N 10mVrms W N 0 50Vrms W N 0 64Vrms 14 J1 IC161 1...

Page 46: ... 271A E SPECIFICATIONS GENERAL Frequency Range TX K M4 144 148MHz E 144 146MHz M2 M3 136 174MHz RX K E M2 M3 136 174MHz M4 144 148MHz Mode F3E FM Antenna Impedance 50Ω Usable Temperature Range 20 C 60 C 4 F 140 F Power Supply 13 8V DC 15 11 7 15 8V Grounding Method Negative ground Current Transmit max K E M2 M3 13A or less M4 8A or less Receive at 2W output 1 0A or less Frequency Stability 20 C 60...

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