Kenwood TK-250 Service Manual Download Page 1

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Summary of Contents for TK-250

Page 1: ...ALLA TION 5 REALIGNMENT 8 CIRCUIT DESCRIPTION 16 SEMICONDUCTOR DATA 24 DESCRIPTION OF COMPONENTS 31 PARTS LIST 33 EXPLODED ViEW 40 PACKING 42 TERMINAL FUNCTION 43 ADJUSTMENT 46 PC BOARD VIEWS VCO UNIT X58 4130 10 51 VCO UNIT X58 4290 50 52 TX RX UNIT X57 444X XX A 3 53 TX RX UNIT X57 444X XX B 3 57 TX RX UNIT X57 4442 71 A 3 61 TX RX UNIT X57 4442 71 B 3 65 TX RX UNIT X57 444X XX C 3 69 SCHEMATIC ...

Page 2: ...ified secure and any open connectors are properly termi nated SHUT OFF and DO NOT operate this equipment near electrical blasting caps or in an explosive at mosphere This equipment should be serviced by a qualified technician only SERVICE This radio is designed for easy servicing Refer to the schematic diagrams printed circuit board views and alignment procedures contained within NOTE WE CANNOT gu...

Page 3: ...the set when pulling it out use a screwdriver covered with a piece of cloth to depress the side of the main unit báttery connector and remove the case 2 Remove the two shield plate screws f the speaker connector the three contral printed circuit board screws and the two side switch FPC screws 0 3 Flip over the control printed circuit board and remove the three connectors 0 3 ...

Page 4: ...he d p è U J G I O o f C X i o 4 5 Remove the final shield plate remove the two screws i the three TX RX printed circuit board screws D and the two shield cover attachment screws e and remove the shield cover Remove the two antenna co axial connector screws and remove the seven sol dered connections You can now remove the TX RX unit 6 Remove the nine soldered connections and remove the shield plat...

Page 5: ...t see Step 1 above from the left hand side and align it properly The sheet adhesive is very strong so please align carefully Press the exposed port ion of the adhesive surface firmly into place f 3 Pee10ft the remainder of the brown backing material on the back side and press 0 the sheet onto the main unit TK 250 4 Remove the backing material 0 from the front side and press the dressing panel 0 in...

Page 6: ...ide apply the adhesive sheet see Step 1 above from the left hand side and align it properly The sheet adhesive is very strong so please align carefully Press the exposed portion of the adhesive surface firmly into place 3 Pee10ft the remainder of the yellow backing material on the back side and press e the sheet onto the main unit 4 Remove the backing material 1 from the front side and press the k...

Page 7: ...move the two screws j and remove the shield plate Insert the keypad flat cable into the connector CN204 fold the flat cable as shown in the figure so that the cushion is inserted 0 and with the keypad bent back out of the way press it into place 7 While pressing on the flat cable of the keypad bend it under the shield plate sandwich it there replace the shield plate and tighten the screws Pee10ft ...

Page 8: ...nction data and channel settings are transferred from or to an IBM PC Oestination data function data and channel data settings are transferred from or to another transceiver 2 Self programmnig Wh en conducting self programming clear function mode channel setting mode function setting mode please remove the TX RX unit B 3 chip jumper R332 Note Self programming is 32ch model setting function for one...

Page 9: ... REALIGNMENT TOP VIEW LCD CHANNEL SELECTOR KNOB VOU POWER SW TOP PANEL KEY LEFT SIDE VIEW FRONT VIEW RIGHT SIDE VIEW LAMP DRESSING PANEL or DTMF KEY PAD Option LCD SP MIC JACK LO SCN BUSY TA MON CALL Bê tB tB tB tB 9 ...

Page 10: ...mit frequency and transmit signaling for each channel are set NOTE Self program ming mode is function for 32ch model When entered Self programming mode channel setting has been 32ch To 160ch version set on for using FPU 1 Receive frequency setting mode If there is no data stored in the E2PROM is displayed If the LO key is pressed the initial frequency is displayed If there is data stored in the E2...

Page 11: ...ing setting mode If th ere is no data stored in the E2PROM is displayed If the LO key is pressed the intial OT value of 67 0 is displayed If the LO key is pressed again the initial DOT value of 023N is displayed If there is data stored in the E2PROM the signalling is displayed If the TA key is pressed OT The mode changes between the EIA mode and the fine tuning mode DOT The variabie digit changes ...

Page 12: ...z UPPER VHF2 136 150 45 05MHz UPPER 2 Battery saver When the channel selector is turned the display changes rOFF S M L OFF I 3 Time out timer When the channel selector is turned the display changes 30 60 90 120 150 180 210 240 270 300 60 I 4 Scan When the channel selector is turned the display changes rOFF SCAN SCAN I 5 DELETE ADD When the channel selector is turned the channel changes rDIA 1 DI A...

Page 13: ...own the LAMP and LO keys and turn the POWER switch on Hold down the LAMP key for at least two sec onds When the PC rnode in entered PC is displayed on the LCD When data transmitting from transceiver the red LED goes on Wh en data receiving to transceiver the green LED goes on Notes Do not connect the interface cable in the normal receive mode The data stored in the personal computer must match VHF...

Page 14: ... PC mode the LAMP key remains iIIuminated for two seconds Additionally en the data trransmission side press the DIA key to enter the clone mode C appears on the display Q When the MONI key on the transmitter is pressed the E2PROM data is copied and the ON AIR indicator lights The state of the receiver does not change After about 40 sec Fig 2 onds the E2PROM copying ends and END is displayed on tra...

Page 15: ...key is pressed Scan delete add change 1 Talkaround The talkaround function is used to transmit data with the receive frequency and receive signaling The talkaround is turned on or off each time the TA key is pressed It does not work during scanning The talkaround is turned off if the channel is changed with the encoder or if scanning starts The talkaround function can be selected in the self progr...

Page 16: ...perate in the frequency range of 150 to 174MHz K M and 136 150MHz K2 M2 3 1 Front end RF amplifier An incoming signal from the antenna is applied to an RF amplifier 017 after passing thraugh a transmitlreceive switch circuit 08 and 09 are of After the signal is amplified the signal is filtered by a Band shift type band pass filter to elimi nate unwanted signals before it is routed to the first mix...

Page 17: ...h circuit which consists of IC208 2 2 and 0203 is applied to the microprocessor The microprocessor passes information to the shift registor IC213 and it contrals the mute contrallines AF MUTE and AC according to the input signal noise pulse and the mi croprocessor task condition Item Rating Nominal center frequency 455kHz 6dB band width 6 0kHz or more 40dB band width 12 5kHz or more Ripple 1 5dB o...

Page 18: ... of the low pass filter network IC216 is passed to the DIA converter IC206 for maximum deviation adjust ment and the summing amplifier IC201 2 2 before being applied to a varactor diode 0504 in the voltage controlled oscillator VCO located in the frequency synthesizer section I I LPFI IC207 2 2 IC216 C257 R263 R268 1 2 R252 3 1 6 0 8 Q202 I M li 1 Cl 0 I 1 I H Cl ü C266 I 11 IC216 LPF T 2 2 5 R279...

Page 19: ...t stabilizes the transmitter output power at a pre determined level by sens ing the collector current of the final amplifier transistor in the power module The voltage comparator IC4 compares the voltage obtained by the above collector current with a refer ence voltage set using the microprocessor and 018 An APC voltage proportional to the difference between the sensed voltage and the reference vo...

Page 20: ...or frequency is controlled by applying the VCO control voltage obtained from the phase comparator to the varactor diodes 0501 in transmit mode and 0502 and 0503 in receive mode The TI R pin in set high in receive mode causing 0501 and 0502 to turn off 0504 and turn on 0505 and is set low for transmit mode The outputs from 0504 and 0505 are amplified by 0503 and outputed to the buffer amplifiers 5 ...

Page 21: ...ocessor or shift register IC203 and IC204 in the con trol unit provide a 5V supply for the control and display cir cuits 6 2 Battery sa ver If no activity is detected squelch closed on the channel the units enters into the battery save mode controiled by the microprocessor and shift registor In this mode SAVE line is set low causing Q4 to disable 5SV 5T CV o 5SV VCO 5R Q4 I DC SW I Q7 0 cr t Q5 cr...

Page 22: ...viation adjustment and the sum ming amplifier IC201 7 2 OT DOT decode A part of the recovered audio signal obtained at the am plifier IC208 1 2 are the OT and DOT tones and are low pass filtered by IC214 1 2 and passed to the microproces sor for decoding L S D QT DQT from CPU IC221 IC201 2 2 5 R219 6i18 5MT BIAS2 R2S Rl66 A2G8 N SM IQ D Ot T IC214 I C208 1 2 a 1 2 3 3 l 2 4 C260 a LSD IN to CPU IC...

Page 23: ...m the DTMF keypad to the microprocessor The microprocessor passes this informa tion to the DTMF encoder IC219 for encoding The en coded signal is then passed to IC206 DI A convertor for DTMF deviation adjustment This signal provides a TX DTMF tone and a RX DTMF tone The TX DTMF tone is passed to the pre emphasis circuit mie amplifier and then to the VCO The RX DTMF tone is passed to the de emphasi...

Page 24: ...6 1 51 AD1 P07 2 50 ADO P10 3 49 o ALE P11 4 48 WR P12 0 5 47 RD P13 6 46 RESET P14 0 7 45 EA P15 0 8 44 o A15 P16 0 9 43 o A14 PH 0 10 78312AGF3553BE 42 A13 P20 0 11 41 A12 P21 INTO0 12 40 o A11 P22 INT10 13 39 A10 P23 INT20 14 38 A9 P24 15 37 A8 P25 PTT 0 16 36 P37 WRPRO P26 D TXD 17 35 P36 DATA2 18 34 P35 RFSH 19 33 P34 QT DOT NNNNNNNNNNC C C OT JCf NUJO C J f tbcn C C C C xx J zzzza J a a a a ...

Page 25: ...stem clock shift contral output P30 SOL I Noise pulse input P31 MON I MONI switch input P32 UL 1 PLL unlock detect input P33 LAMP I LAMP switch input X1 12 000MHz system clock X2 12 000MHz system clock Vss GND ANO LSDIN I Low speed data input AN1 I Open not used AN2 BATT I BATT check input AN3 SELF I SELF programming prat eet input AVREF 5V AVss GND P34 OT DOT 0 Low speed data signalling output P3...

Page 26: ...en not used COMO 0 LCD COMO 50 P30 0 8erial RX data output COM1 0 LCD COM1 51 52 P31 32 Open not used COM2 0 LCD COM2 53 P33 0 LAMP LED output COM3 0 LCD COM3 54 VDD 5V BIA8 0 LCD power supply voltage 55 XT1 5V VLCO VLC2 LCD voltage level generator 56 XT2 Open not used P40 P43 Open not used 57 NC Open not used Vss GND 58 59 X1 X2 I 8ystem clock input P50 0 GREEN LED output 60 P60 I GND P51 0 RED L...

Page 27: ...om the DI terminal is input to the 12 bit shift register DI I serial data input terminal Input serial data 12 bits long VI3 I DIA converter input terminal V03 0 8 bit resolution DIA terminal V04 0 8 bit resolution DIA terminal VI4 I D Aconverter input terminal VI5 I DIA converter input terminal V05 0 8 bit resolution DIA terminal V06 0 8 bit resolution DIA terminal VI6 I DIA converter input termin...

Page 28: ...the 4 bit code OE I 01 04 3 state control terminal OE H enable OE l high impedance Vee Power supply terminal normally 5V PO I Enters standby mode when l is applied OSCE I Oscillation stage control terminal IN I Signal input terminal Vss Power supply terminaL Nrmally OV X2 0 3 579545MHz quartz crystaL X1 I 3 579545MHz quartz crystaL Connected to VOO when using an extemal clock ClK 1 0 OSCE H extern...

Page 29: ...layout Pin function VCC WC SCL SDA o Pin No Pin Name 1 0Function 1 3 AO A 1 A2 I Slave address setting terminal 4 Vss Referenee voltage for alil O OV 5 SOA 1 0 slave and word address serial data in put output 6 SCL I Serial doek input 7 WC I Con neet to GNO 8 VCC Conneet to the power supply AD A1 A2 GND The SOA terminal is the N eh open drain output so use with a pull up resistor attaehed to the o...

Page 30: ... T E M67755LA K2 M2 Equivalent circuit diagram 1 I I 1 I I J 1 IT r I I I I tr I 1 L _ Electrode configuration 1 Input terminal 2 First power supply terminal 3 Base bias power supply terminal 4 End power supply terminal 5 Output terminal 6 Fin earth 30 ...

Page 31: ...2SK1215 E RF amp DTA123JE DC switch DTC144EE DC switch 2SC4617 S Temprature protection D1F20 Reverse polarity protection 1SS368 Current steering 1SS368 Current steering HVU350 Varactor tuning HVU350 Varactor tuning HVU350 Varactor tuning MI809 RF switch 1SS312 RF switch HSM88AS Overload protection TX RX UNIT Control section X57 4440 10 8 3 Ref No Parts No Description TA75W01 FU Buffer amp Suming a...

Page 32: ...A 1362 GR DC switch 2SC4215 Y Clock frequency shift 2SK1588 Audio mute switch DTA144EE DC switch 2SK879 Y MIC AMP level control DA221 Voltage clamp DA221 Voltage clamp DA221 MIC AMP detection TX RX UNIT Display section X57 4440 10 C 3 Ref No Parts No Description 75308BGK739BE9 Microprocesser display S 8054ALB LM T1 Reset Switch B30 2019 05 Red green LED 830 2047 05 LCD back light VCO UNIT X58 4130...

Page 33: ...E TAPE ACCESSORIES 20K29 4800 04 KN08 RELEASE 20 K29 4917 02 KN08 PTT K29 4918 03 KN08 VOLUME 3A K29 4919 03 KN08 KEY TOP 3AK29 4920 03 KN08 CHANNEl SElECTOR New Desti Ref No Adlkes parts Pans No_ Description nation A 38 N09 1492 05 PAN HEAO SCREW M2 6X35 8lK 8 28 38 N09 2053 05 SEMS SCREW M2X35 C 20 N09 2185 05 81NOING HEAO SCREW M26X8 0 3A N 14 0545 04 CIRCUlAR NUT CH VOl E 3A N 14 0560 04 CIRCU...

Page 34: ... No Admess parts Parts No Description nation C93 CK73GBl H102K CHIP C 1000PF K C94 C92 0578 05 CHlp ELE 22UF l6WV C95 CK73GB1 H102K CHIPC 1000PF K C96 CC73GCH1 H1R5C CHIP C 15PF C C97 98 CK73GB1 Hl 02K CHIPC 1000PF K C99 CC73GCH1 H270J CHIP C 27PF J C100 CK73GB1 Cl 04K CHIPC 0 10UF K C101 CC73FCHl H150J CHIP C 15PF J K2 M2 Cl01 CC73FCH1 H270J CHIP C 27PF J KMTE C102 1 03 CK73GBl H102K CHIPC 1000PF...

Page 35: ...221 K CHIPC 220PF K C281 CC73HCH1El01J CHIPC 100PF J C282 291 CK73HBl E221 K CHIPC 220PF K C292 CC73GCHl H221J CHIPC 220PF J C293 294 CK73HBl E221 K CHIPC 220PF K C300 301 CK73HBl E221 K CHIP C 220PF K C302 CK73GBl Hl 03K CHIP C 0 010UF K C303 CK73FFl C334Z CHIP C 0 33UF Z C304 311 CK73HBl E221 K CHIP C 220PF K C312 CC73GCHl H221J CHIP C 220PF J C313 315 CK73HBl E221 K CHIP C 220PF K C316 317 CK73...

Page 36: ...OOK J 1 16W 36 New Desti Ref_ No Address parts Parts No Description nation R6 RK73GB1J473J CHIP R 47K J 1 16W R7 RK73GB1Jl02J CHIP R 1 0K J 1 16W R8 9 RK73GB1J472J CHIP R OK J 1 16W Rl0 RK73GB1Jl02J CHIP R 1 0K J 1 16W Rl1 RK73GB1Jl03J CHIP R 10K J 1 16W KMK2M2 Rl1 RK73GB1J223J CHIP R 22K J 1 16W T E R12 RK73GB1J473J CHIP R 47K J 1 16W R14 RK73GB1Jl02J CHIP R 1 0K J 1 16W R16 RK73GB1Jl02J CHIP R 1...

Page 37: ...GB1J824J CHIP R 820K J 1 16W R248 RK73GB1J153J CHIP R 15K J 1 16W R249 RK73GB1J822J CHIP R 82K J 1 16W R250 RK73GB1Jl04J CHIP R lOOK J 1 16W E R250 RK73GB1J273J CHIP R 27K J 1 16W K M T R250 RK73GB1J273J CHIP R 27K J 1 16W K2 M2 R251 RK73GB1J473J CHIP R 47K J 1 16W R252 RK73GB1J683J CHIP R 68K J 1 16W E R252 253 RK73GB1Jl03J CHIP R 10K J 1 16W K M T R252 253 RK73GB1Jl03J CHIP R 10K J 1 16W K2 M2 R...

Page 38: ...ODE MI809 DIODE lSS312 DIODE 38 Adm ess New Desti Ref No_ parls Palts No Description nation 010 HSM88AS DIODE 0202 204 DA221 DIODE E 0202 203 DA221 DIODE K M T 0202 203 DA221 DIODE K2 M2 ICI NJU7201 U50 ICIVOLTAGE REGULATOR IC2 MC3372V ICIFM IF IC3 MB1512PFV GBND IC PLL FREOUENCY SYNTHESIZER IC4 NJM 1458M ICIOP AMP X21 IC5 M677 55HA ICIPOWER MODULE 150 174MHz6WJ KMTE IC5 M67755LA IC POWER MODULE 1...

Page 39: ...1 16W RK73HBl J822J CHIP R 82K J 1 16W New Desti Ref No Address part Parts No Description nation R510 RK73H81J332J CHIP R 33K J 1 16W RS11 RK73H81J472J CHIP R OK J 1 16W RS12 RK73H81J822J CHIP R 8 2K J 1 16W R51S 516 RK73H81J271J CHIP R 270 J 1 16W K M RS1S 516 RK73H81J331J CHIP R 330 J 1 16W K2 M2 0501 1SV228 VARI CAP DIODE 0502 503 1T363A VARI CAP DIODE 0504 MA360 VARI CAP DIODE 0501 UMG2 DIGITA...

Page 40: ...NUT N14 0560 04 F NUT N14 0562 04 H M2x2 0 N39 2020 46 J M2x8 0 N 8 2080 46 K M2x5 N09 2251 05 L M2x4 F Tap N88 2004 46 34 59 EN1 VR I 701 DISPLAY UNIT X5 444 C 3 54 III F o 1 cs 67 Dil f h k LCD11 i 69 D J 116 J 68 V 35 E 56 7 26 58 Hx2 40 Parts with the exploded numbers larger than 700 are not supplied ...

Page 41: ... 05 C M2 6x8 N09 2185 05 G WASHER N17 1026 60 M SCREW SET N99 0387 05 TK 250 EXPLODED VIEW OPTION KOM ACCESSORY 15 1 11 701 50 Mx2 ACCESSORY ACCESSORY 61 Parts with the exploded numbers larger than 700 are not supplied 41 ...

Page 42: ...ection Bag H25 0085 04 100x200 7t 37 Packing Fixture H12 1470 02 39 Protection Bag H25 0085 04 100x200 T90 0450 05 T90 0381 05 36 Item Carton Case H52 0560 04 13 Warranty Card K K2 846 0409 40 14 Instruction Manual B62 0446 00 42 ...

Page 43: ...Pin Name 110 Function 1 B I Extemal power supply input TX RX UNIT X57 4440 10 B 3 Control section Connector No Pin No Pin Name 110 Function 1 E GND DE I AF detection signal input RX MD a AF modulation signal output TX BL a AF modulation signal Low Speed Data output TX CK a PLL clock data output PE a PLL enable data output OT a PLL data line output KY a Normally 5V Transmit OV UL I Normally 5V Tran...

Page 44: ...Connector No Pin No Pin Name 1 0 Function 1 DKEY1 I DTMF KEY DKEY2 I DTMF KEY DKEY3 I DTMF KEY DKEY4 I DTMF KEY DKEY5 I DTMF KEY DKEY6 I DTMF KEY DKEY7 I DTMF KEY DKEY8 I DTMF KEY TX RX UNIT X57 4440 10 B 3 Contra section Connector No Pin No Pin Name 1 0 Function 1 5M 0 5V TD 0 Serial control signal output RD I Serial control signal input RT I Reset signal inputE GND B 0 Power output after passing...

Page 45: ... GND RST 0 Reset signal output RXD 0 Serial control signal output TXD I Serial control signal input 5M I 5V vce UNIT X58 4130 10 Connector No Pin No Pin Name 1 0 Function 1 MOD I AF modulation signal input TX T R 1 Normally 5V Transmit OV LV I PLL loek voltaqe input O 5V vce UNIT X58 4130 10 Connector No Pin No Pin Name 1 0 Function 1 OUT 0 VCO output E GND 5V I 5V 45 ...

Page 46: ...able frequency Up to 520MHz 2 Impedance 50Q unbalanced 3 Measuring range Full scal of 10W or so 4 A standard cable 5D2W 1m must be used 5 RF VTVM RF V M 1 Measurable frequency Up to 520MHz or sa 6 Linear Detector 1 Measurable frequency Up to 520MHz 2 Characteristics are flat and CN is 60dB or more 7 Digital Voltmeter 1 Voltage range FS 18V or so 2 Input resistance 1MQ or more 8 Oscilloscope 1 Meas...

Page 47: ...2 TX frequency RX frequency TX frequency I RX frequency 162 000MHz 162 100MHz 143 000MHz I 143 100MHz 150 000MHz 150 100MHz 136 000MHz 173 990MHz 173 970MHz 149 990MHz I 149 970MHz 162 000MHz 149 000MHz 162 200MHz 149 200MHz 162AOOMHz 149 AOOMHz Signaling No list ignaling ENC TONE DEC TONE 1 NONE NONE OT OT DOT DOT NONE 2TONE NONE DTMF DTMF NONE DTMF NONE 100Hz square wave NONE 47 ...

Page 48: ...st freq O 6 1 7V fRL check Helical Measurement Adjustment Condition Test Specifications Terminal Unit Parts Method Remarks 1 CH Channel with center freq Trk Gen TX RX ANT TX RX L9 Adjust wave form to figure at below fRM Spectrum N3 TP4 N3 L10 Conneet the spectrum analyzer Analyzer RF L12 L17 Check WAVE shift to right 3 CH Channel with lowest WAVE shift to left CAUTION Wh en using an extern al powe...

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Kenwood TK-250, Service Manual

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