Kenwood 941 Service Manual Download

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Summary of Contents for 941

Page 1: ...L DIAGRAM 2b FX R ONIT1x57 4590 XXI BIZ 67 G CIRCUIT DESCRIPTION 27 T X R X U N I X O X X A121 71 SEMICONDUCTOR DATA 34 SCHEM TIC A G R A M 77 DESCRIPTION OFCOMPON NTS b 39 SPECIFICA IONS 83 I PARTS LIST 41 KT 19 ACCESSORYCONNECTION CABLE1 BACK COVER EXPLODED VIEW 55 KDD 4 D rMF DECODER BACK COVER PACKING 56 KPG 25D PROGRAMMING DISK BACK COVER a ...

Page 2: ...pack the radio from its shipping container and check for accessory items If any item is missing please contact KENWOOD immediately 2 LICENSING REQUIREMENTS Federal regulations require a station license for each radio installation mobile or base be obtained by the equipment owner The licensee is responsible for en ring transmitter power frequency and deviation are hin the limits permitted by the st...

Page 3: ... and wiring 1 Th s rad o may be nstalled In negatlve ground eec tr cal systems only Reverse polar ty will cause the f cable fuse to blow Check the veh cle ground polar I t y before nstallat on to prevent wasted time and 1 effort k 2 Connect the posltive power lead d rectly to the ve t i h cle battery pos tive term nalConnect ng the Posi t tive lead to any other posltlve voltage source In the I veh...

Page 4: ...nge MHz TX 806 825 851 870 RX 851 870 TX 896 902 935 941 RX 935 941 I See page 21 See page 21 Are you using the external speaker KES 3 External speaker Option 1 Option Transceiver programming Option See page 18 See page 20 KCT 18 Ignition sense cable N0 Option RF power 15W 15W See page 13 A personal computer IBM PC or compatible programming interface KPG 4 c Delivery Type TK 940 K TK 9 41 K and pr...

Page 5: ...own the Clear to talk system number changes continuously After the External DTNlF decoder The optional KDD 4 DTMF system number reaches the highest system number it decoder is required goes back to the lowest system number System Test mode numbers not set are skipped Horn alert port Data port GROUP UPIDOWN key This key is operated in the same way as the SYS 1 2 Trunked System Features TEM UPIDOWN ...

Page 6: ... number 1 MAX 32 Only the programmed systems are displayed The system display is located above the SYSTEM UP DOWN key Group display Shows the selected group rlumbei 1 MAX 250 Zero ndicates group 10 Only the programmed groups GROLIP LIPIDOWN key are d splayed The group d splay1 s located above the Scan indicator The amark on the display goes on in system scan mode Delete 1 indicator When a system l...

Page 7: ...d to lock systems out of the scan sequence and can be selected by pro gramming in the following two ways Fixed lockout The system to be locked out is selected by program ming When a locked system is selected the Delete Indicator appears on the left of the SYSTEM indi cator The revert system is scanned even if it is locked out If there is a locked system the Delete b indica tor flashes during fixed...

Page 8: ... 15 seconds to ten mlnutes for patch and Interconnect operat ons If the transmlt for longer than the pro ter IS dlsabled and a warn P l T button IS held down he P l T button IS released ute for dlspatch and three 3 9 Priority ID Codes The priority of the programmable decode ID codes for each system is as follows 1 Fixed ID code 1 2 F xed ID code 2 3 Selected ID code 4 Other selectable ID codes Gro...

Page 9: ... tone sbunds the mode IS termlnated and the trans celver returns to the flrst system If the access IS suc cessful the mode IS termlnated and the searched sys tem becomes the new selected system If durrng scannlng the scan stops 3 15 Transpond Thts feature can be programmed to turn on and off each group If the ID of the group for which trans d IS enabled is received two data messages trans ID and t...

Page 10: ...is output and this mode is terminated When the talk Deny tone ends the revert system group returns When the scan This tone is output if the AUTO TEL function is set mode is effective the scan resumes The AUTO TEL the queue tone is output but the TEL channel cannot feature can be programmed to turn on or off for each be accessed within 60 seconds It is similar to the in system tercept tone The m d ...

Page 11: ...nned The KDD 4 can be set with the decode ID of each group If it is supporled the following features are available Audio mute If the decode latch Input port is low during reception and the LTR data or signaling matches when the squelch is open if signaling is not set the audio is out put During systemlgroup scanning the SCAN dis play changes to the systemlgroup display or alphanu meric display If ...

Page 12: ...an A scan list can be set for each system The list to be scanned can be changed by changing the display system If many systems have been set the scan speed can be increased by narrowing the systems to be scanned with scan lists 3 26 Data Port The following ports are available for external equipment when the KCT I9 is used B Terminal functions Digital HOR Horn alert port For details of operations s...

Page 13: ... 3 Programming Software Description KPG 25D is the programmlng software for the TK 9401941 supplled on a 3 5 or 5 25 floppy disk Thls software runs under MS DOS vers on 3 3 or later on an IBM XT AT or PS2 or on a compatible mach ne Data car de Input to or read from the TK 9401941 and ed tedon the screen Programmed data can be 4 4 Data Program Mode In thts mode data IS wr tten Into the flash memory...

Page 14: ... slave set to show that it is receiving data 5 When cloning is complete the amark on the master set disappears and CLOIVE changes to END The slave set is automatically reset and enters user mode If cloning fails the master set shows ERROR Repeat steps 4 and 5 If you wish to clone several sets switch each of them on and reDeat 4 and 5 5 Description of Each Modes 5 1 Dealer mode To enter this mode h...

Page 15: ... None No decode squelch can be adjusted 100H sqilare wave No decode squelch can be adjusted LTR format Decode squelch cannot be adjusted QT 67 OHz Decode Squelch cannot be adjusted QT 151 4Hz Decode squelch cannot be adjusted QT 210 7Hz Decode squelch cannot be adjusted DQT 023N No decode squelch cannot be adjusted DOT 754N No decode squelch cannot be adjusted Fj varied between 1 to 256 1 SCAN key...

Page 16: ...F Option 1 1 KDD 4 assembly 1 Solder the 9 pin leads with connector to the KDD 4 board locations designated with the unit specification numbers Fig 1 Fig 1 2 Put an insulating tube around the KDD 4 board and heat it so that the tube encases the board Fig 2 ...

Page 17: ...ansceiver and the control panel Fg 3 Fig 3 2 Install the KDD 4 on the TX RX unit B12 Fig 4 1 Attach the pad to the KDD 4 0 2 Plug the KDD 4 connector into CIV203 of the TX RX unit BIZ 0 3 Attach the KDD 4 to the TX RX unit 0 4 Reinstall the panel and the two halves of the cases Cornpon cide Fig 4 ...

Page 18: ...pen c rcu t 1 I supply Fig 5 JU3 Shorted Open Shorted Open Shorted 2 Accessory Connection Cable KCT 19 Option The KCT I9 is an accessory connection cable for connecting external equipment The connector has 15 pins and the necessary signal lines are selected for use JUJ E A A C C 2 1 Installing the KCT 19 in the transceiver 1 Remove the upper and lower halves of the transceiver case and lift the DC...

Page 19: ...unction DC supp PTT inout No A A 1 A 2 1 A 9 D 4 Dl 1 Data mod innut I No lB C DI D 2 D 5 I A I3 E I LOK Link corn lete o t o i l i I A I 2 Narne HK ME DTC I Data PTTinput Function M C hook input MICGND HOR SQ SP A I 4 A I 5 Refer to Term na function on page 63 fneed description in detail The functions of A 14 and A I5 are changed if the connector E are connected to CN2 or CN3 of the radio Horn Al...

Page 20: ...T B 19 section 1 p 2 Insert the KCT 18lead terminal Q into pin 3 of the I square plug 0 supplied with the KCT 19 theri t insert the square plug into the KCT I9 connector 01 3 2 Modifying the transceiver Modify the transceiver as follows to turn the power ontact or the Horn Alert or Manual Relay function on and off 1 with the ignition key i 1 Remove the lower half of the transceiver case KCT 18 2 S...

Page 21: ...r jack on the rear of the transceiver 1 4 2 KES 4 Option The KES 4 is an external speaker used w t h the r accessory connection cable Connection procedure 1 Install the KCT 19 in the transceiver See the KCT 19 section 2 Insert the crimp terminal into the square plug supplied with the KCT I9 3 Connect CN5 of the transceiver to connector C of the KCT 19 instead of t o the internal speaker connector ...

Page 22: ...our car 1 Reniove the control panel and the TX RX unit B 2 control section Fig 12 Fig 12 2 Fo1 dthe flat cable 0 differently Q1 3 Turn the control section through 180 degrees 0 and rriount it on the transceiver 0 4 Insert the flat cable into control section connector CN201 0 5 Turn the pnel through 180 degrees and mount it on the transceiver Refit the two halves of the case to complete installatio...

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Page 27: ...Hz TK 940 3 Receiving System 3 1 RF unit An incoming RF signal from the antenna terminal passes through the antenna switch D19 D20 and D21 are off and then the bandpass filter L9 The signal is ampliked by RF amplifier 024 and passes through the bandpass filter L6 again The resulting signal goes to the flrst mixer 021 where it is mixed with the first local oscillator signal output from the frequenc...

Page 28: ... to audio amplifier IC11 is amplified and is output to the speaker 3 4 Squelch circuit The detector output is amplified by IC2 212 and passes through a high pass filter consisting of IC204 2 2 which removes the noise components from the signal Q202 converts the noise pulse level by hysteresis and applies it to the CPU lC209 The CPU counts the pulses integrates them and turns the squelch on and off...

Page 29: ... 4 2 Final amplifier 4 3 APC circuit The signal from the PLL is amplified by t w o power The direct current that flows through the final modules ICI2 and IC14 to an output level of 15W and module lC14 produces a voltage across resistors goes through the harmonic filter and antenna switch R108 R109 and R110 This voltage is applied to pin 6 D20 and on to the antenna terminal of lC13 2 2 and is input...

Page 30: ...nal in IC1 The output from the phase coniparator goes through the charge pump In ICl and low pass filter and on to the varactor diodes D51 and D52 in the VCO unit keeping the VCO frequency constant The other output from Q53 is amplified by the RF amplifier iQ181 and output to the transmit or receive unit vla the RF switch D17 I PLLJVCO UNIT _I _1 I IC209 rl D A irl __ __ Us Q52 Q53 I 018 D l 7 PLL...

Page 31: ...e CR low pass input decode data filter and goes to the summing amplifier IC212 in the 6 Sending encode data microphone amplifier It is mixed with the audio signal 7 Sendlng data to the D A converter and output to the splatter filter It then goes to the D A 6 1 Memory circuit converter IC6 and on to the VCXO and VCO IC201 is a 2 Kbit EEPROM that stores adjustment 6 3 RX decode data and backup data ...

Page 32: ...nimum of 800mA 6 6 Power supply circuit D8 protects 1C1 against overvoltage Each time a pulse comes from the PSW terminal the IC1 output is reversed The reversed output signal passes through 0 1 and Q3 and drives 0 4 A voltage must be applied to the IGN terminal If 24V is supplied to the transceiver by mistake Q2 turns on and 0 3 and 0 4 are forced off so the transceiver does not turn on If the SB...

Page 33: ...LCD can indicate alphanumeric characters 13 segments 8 d gits TX BUSY CALL SCAN Talk around Option AUX TEL and Delete 7 2 Power switch circuit Each time the power key IS pressed a pulse IS sent to the TX RX unlt to turn the transceiver on or off 7 3 Tone generator The beeps and alert tones are generated by combining square wave signals of about 700Hz 900Hz and 1500Hz generated by the CPU These sig...

Page 34: ...Vour7 VlN7 GND RESET V o r r f Da VING V O U T Vou15 VIN5 18 17 16 I I I I I I I I I I I I I I I I 7 8 VIN V O U T VOUT2 VlN2 V00 LD CLK Dl V I N V O U T VOUTA v 1 4 Audio Power Amplifier LA4422 TX RX Unit IC11 Terminal connection diagram Block diagram DC BS IN OUT NFb NFa I I I 8 GND ...

Page 35: ...Vcc Terminal function I PI name I Functon Ser al data Ser al clock No connect GND START STOP LOGIC SERIAL SCL SDA 41 O A 2 A1 Ao O 1 OUT CONTROL EN H V PUMPfllMlNG D LOGIC D LOAD 4 DEVICE DATA REGISTER ADDRESS COMPARATOR LOAD INC I Riw DATAWORD O ADDRESS 2 COUNTER n EZPROM X Y DEC w SERIAL MUX b DIN b C DourIACK LOGIC ...

Page 36: ...ith programming Data group control input MDT KEY Transmit Active H GND For display serial RX data input HOOKfdata input with programming Data inputwith clone 23 P33 CTRLI I Option signaling decode latch 62 PO3 0 Shift register a b l e PO4 24 XI 12 000MHz 63 0 For display serial TX data output 25 X2 PO5 0 P25 RXD P26 SCK P27lCTS RFSH P3O CIO P31 CTRLO 3 8 2 1 1 28 29 30 31 T AVREF O I 0 O 32 33 34 ...

Page 37: ...tch input SCAN swltch npui Volume up switch input Volurne down switch input Group up swltch input Group down switch input System up switch input System down swl h input System reset nput LCD output 532 S21 Function LCD output S20 SII LCD COMO COM3 output LCD power supply voltage LCD voltage level generator Open not use GND Open not use HOOK PC ser al data input Open not use Ser al data input PTT P...

Page 38: ...T A 1 DIVIDER LOGIC REFout CONFIGURABLE 1 N 3 13 DOUBLE BUFFERED Bit GrabberTMR REGISTER 16 BlTS t Bit Grabberm C REGISTER 8 BITS 1 I STANDBY POR LOGIC Bn Grabberm A REGISTER 24 BlTS 6 STAGE 12 STAGE A COUNTER N COUNTER fin 11 64 65 10 PRESCALER CONTROL fin t LOGIC I A Y y TEST1 SUPPLY CONNECTIONS PIN12 V C C VcTO INPUT AMP AND 64 55pnCSCALERl PIN5 VPD VcTO PHASEIFREQUENCY 9RS A AND 8 PIN14 VDD V ...

Page 39: ...ch On when power swltch on 2SA1641 S T Q4 DC switch On when power swltch on Q5 DTA114YU DC switch Oh when power switch off then D22 turn on Q6 7 2SB1188iQ R DC switch RX OV TX 8V 0 8 2SA1362iY DC switch RX 8V TX O V 0 9 DC switch On when PLL lock Q10 On when PTT switch on DC switch 0 11 DTC114EU On when RX Q12 DTC114EU On when TX DC switch Q13 DTC114EU DC sw tch On when horn control on Q14 2SD1624...

Page 40: ...X58 4170 XX 10 TK 940 11 TK 941 MI809 MA4P1250 MI809 MA77 DA204K 1SS301 Ref No IC1 Q1 Q2 Q3 p p TWRX switch p p p p TWRX sw tch TWRX swltch DC swltch Surge absorption DC swltch On when microphone mute on 2SK508NViK52 2SC3356 LCD ASSY B38 0731 05 Parts No SC370651F DTC143EK 2SA1586 Y GRj 2SC3356 Q53 D1 D51 52 D53 Oscillator p p p p Buffer ampllfler Doubler UseIFunction OperationICondition PLL syste...

Page 41: ...4 7pF 10 75 RESISTORS Chip resistor Carbon EX Q 7 3 E B B m 1 2 3 4 5 6 7 T Blue 470 1st Word Coloi p p m T Chip B F U Violet 750 L Red 80 C Black 0 M i 2 0 C o d e C I Carbon resistor Normal type EX B B 1 2 3 4 5 6 7 D F0 5 k0 25 1 Type ceramic electrolytic etc 5 Voltage rat ng 2 Shape round square ect 6 Value 3 D mension 7 Tolerance 4 Temp coeff c ent P Orange 1 5 0 X 40 20 Dimension Chip capaci...

Page 42: ...S E 3 7 0 4 7 0 0 5 F l u 2 1 2 5 0 4 F l u 2 1 2 6 0 3 F 5 1 U 0 1 6 0 5 F 5 1 00 16 05 GU2 0576 14 G02 07 11 04 G10 0764 04 G10 0765 04 GI I 0 7 2 8 0 4 G13 1468 04 G I 3 092 1 04 G 5 3 0 7 7 6 0 4 H 1 0 2 7 8 4 0 2 H I D 2 7 8 5 0 2 H12 1469 02 H 13 0 9 4 2 0 4 H 2 5 0 0 2 9 0 4 H25 0049 03 H25 0103 04 H 2 5 0 7 9 6 0 4 H52 0603 04 H 5 2 0 6 1 0 0 4 J 1 9 1 3 7 6 1 5 J 1 9 1 4 3 4 0 4 5 2 9 0 4...

Page 43: ...C73CCH lH lUUD CHIP C IUPF D CK73GBlH103K CHIP C U UIUF K CC73GCHlH221J CHIP C 22UPF J ELECTRQ l UUF lUWV UNIT X57 4590 XX CC73CCH1HI01J CK73CBiH102K C C 7 3 C C H I H l U I J CC73CCHIHIOI J CEU4EW1E471M CK73GB l H471K CK73CBIHIU2K y 2 4 0 5 CY2 UU36 U5 CK73CB1H471 K CK73GB l H103K 2 0 5 7 5 CK73G61H471K 9 2 0 0 0 4 U 5 CK73FB1EIU4K CK73GBI H1U3K CK73CB1H472K CK73CB l HiU3K CK73CB1 H lU2K CK73CB1H...

Page 44: ...CI c 4 C e c t0 e c X 5 8 5 5 1 l h j 4 K 3 W W 1 W l C C J G cm cmmc m I P A C I C 8 4 x 4 1 2 I C C G 0 C m W w c n p f r C x 3 c w w w w w C C C3 c C r c c c m I I I I d I I I I I C L C P O U s 1 C m K m CI C C A x r D C C C cf c r 3 m r m c 7 c C o c C n em em em c o c c c C c c c m c c c c c m c c m c c o c 5 c 3 c c c I I I T I C I I I I I I I r I C I I I I I I I I I I I I I I r I I I I I C ...

Page 45: ...H I P C 1 UUPF J C H I P C IPF C C H I P C I 5 P F C C H l P C 4 7 P F J C H I P C l i l U u P F K F I X E D C 6 P F F I X E D C 2 P F F I X E D C IP F C H I P TAN 4 7 U F 6 3WV C H I P C 4 7 P F J C H I P C 1 u O P F j C H l P TAN 1 UUF l6WV C H I P C U l U U F K C H I P C U O I U F K C H I P C 1UUUPF K C H I P C 1 UUPF J C H I P C 1 UUPr J C H I P C I U U P F J C H I P C I U U P F J C H I P TAN ...

Page 46: ...W C W C l L n W K W C W C W C 4 7 x c x c x x c c x 4 4 41 c1 c 4 4 L L 4 J f l m m fimfifi ILr ILr LCIc Ce fi 71 T T T V T T T T C c c c c T C C c c C c C C c c r H 1 x x x x x m c e r r r 3 r T I T I I I X T I I I L I I I I I I I I I I I I I I I I r r D b D D p m m z P fi w e D Z D D Z Z Z Z r r u H H H H r u r 3 c i w H w 3 3 r r r r r r r r D p C 8 C rr C Z i i i T T T T T T T C T W T T T T T ...

Page 47: ...DUCT IH 6 HNH VCXB 1 2 8 M H Z VCXU 1 2 8 M H Z CRYSTAL H E S B N A T Q h 4 4 5 8 2 5 M H Z CRYSTAL HESUNATOh1138 5825MHZ HESBNATUH MCF 4 5 0 3 7 5 M H Z MCF 3 9 0 3 7 5 M H Z C H I P H L OK J 1 1 6 W C H I P H IOK J 1 1 6 W C H l P H U UHM C H I P R 0 BHM C H I P R I OK J 1 1 6 W C H I P R U BHM C H I P H 1 0 K J 1 1 6 W C H I P H O U H h C H I P R I0K J 1 1 6 W C H I P R 1UUK J 1 1 6 W C H I P H...

Page 48: ...J102J RK73CB1 J l U2J HK73GB l J 4 7 1 J HK73GBlJlU2J HK73GBlJ1UlJ RK73GB 1J 5 6 1 J RK73GB l J l U 2 J HK73FB2A271J RK73FB2A2R2J HK73FB2A l 6OJ RK73GB l J331J RK73FB2A271J RY2 06YY 05 RK73FB2AlU2J HY2 06Y9 05 HK73EB2B471J HK73GBlJlUUJ RK73FB2A22UJ RK73FB2A22UJ K USA P Canada T England E Europe i Desti Re ir R k3 CHIP R 22UK J I 1 b W CHIP R 1 5K J l IbW nation marks 1 I CHIP R 4 7K J I lbW CHIP R...

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Page 67: ...LCD ASSY 638 0731 05 Component side view LCD ASSY B38 0731 05 Foil side view ...

Page 68: ...PLLIVCO X58 4170 XX A 2 10 TK 940 11 TK 941 Component side view PLLIVCO X58 4170 XX A121 Foil side view REF GND VIN PLLIVCO X58 4170 XX B12 Foil side view Component side Pattern 1 Pattern 2 Foil side ...

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Page 70: ...1 IRef No IAddress Ref No d d r e s s l component side i Pattern 1 Pattern 2 Pattern 3 Pattern 4 Foil side ...

Page 71: ...ITX RX UNIT X57 4590 XX B 2 Component side view 10 TK 940 11 TK 941 _ Ref N c IC201 IC202 IC203 IC205 IC20E ...

Page 72: ...Component side 1 O Connect 1 and 4 Pattern 1 Pattern 2 Pattern 3 Pattern 4 Foil side I I I I I I DTCI 14EU DTCI44EU ...

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Page 75: ...L I I Component side 2SB1 1 Pattern I Pattern 2 Pattern 3 Pattern 4 I Sidel I I i iI I I I I I I i 1 i I ii I 1 TX RX UNIT iX51 4590 XX 11 12 Foil iide view 10 TK 940 11 TK 941 i i i ...

Page 76: ... M N PC BOARD VIEW d 4 2 INPUT ICalel VIH ...

Page 77: ...TX RX UNIT X57 4590 XX AI2 Component side wiew 10 TK 940 11 TK 941 l2 13 14 o h o n e n t side I I I 75 I I I I I ...

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Page 79: ...f pattern 1 TX RX UNIT TX RX SECTION X57 4590 XX A 2 10 TK 940 11 TK 941 pLL VCo X58 417o XX 0 1 DTC143EK A1 PLL X58 4170 XX A 2 a 2 2SA1586 Y GR 03 52 53 2SC3356 a 5 1 2SK508NV K52 D l 1 S S 3 0 1 D51 52 1T363A D53 MA360 ...

Page 80: ... 7 m a o w m o d m a o n A I Y O f L31Y ZL31X ...

Page 81: ...C MA4P1250 D22 MA77 DTA114EU O X 1 14EU 2SA1641 S T DTA114YU DTA114TU 2SC4226 R24 OTC144EU O X 3 14TK 3SK24 1 R 2SB1370 2SC4094 R 7 E F DTA144EU DTC 114YU 2SA1586 Y GR 4 Crirrp Terminal 33 R95 97 100l 081 X l I X2 XFI I p 1 I7 1 YES I 22 lL77 1563 05 1145 8 2 5 z 4 5 0 3 7 5 1 L72 0 18 1 NO I 0 77 1564 05138 5 0 2 5 6 0 3 7 5 z L72 KCT 18 a L I E aIz23z ...

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Page 83: ... 7 I AT24C02N1OS12 7 NJM78L05UA IC203 HO74HC373FP AT29C256 20TI TC7S32F 78312AGF3563BE TA75S01 F ccrlASS Y DISPLAY S ECTION 838 IC209 78312ACF3563BE ...

Page 84: ...Note 0 Ref No Parts of pattern 1 Eqqzj 10 11 JJP YES SC RESET ...

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