Kenwood NX-840H Service Manual

Uhf digital transceiver

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Function reference (235 pages)

Instruction manual (37 pages)

Instruction manual (18 pages)

Summary of Contents for Kenwood NX-840H

Page 1: Table Of Contents
5 S ERVICE MANUAL B5B-7127-00 NX-840H, NX-840H(U), NX-840 ACC. COPYRIGHT © 2014 JVC KENWOOD Corporation Note : Lead free solder used in the board (material : Sn, Ag, In, Bi, melting point : 227 Centigrade) TABLE OF CONTENTS PRECAUTION............... . . 1-4 SPECIFIC SERVICE INSTRUCTIONS .
Page 2 Neither is any liability assumed for damages resulting from the use of the information contained herein. JVC KENWOOD Corporation reserves the right to make changes to any products herein at any time for improvement purposes. Firmware Copyrights The title to and ownership of copyrights for firmware embedded in KENWOOD product memories are reserved for JVC KENWOOD Corporation.
Page 3 FM Hum & Noise Analog 40dB Audio Distortion Less than 5% Modulation 11K0F3E, 4K00F1E, 4K00F1D, 4K00F7W, 4K00F2D Measurements made per TIA/EIA-603 and specifications shown are typical. JVC KENWOOD Corporation reserves the right to change specifications without prior notice or obligation. (No.RA011<Rev.001>)1-3...
Page 4: Precaution
Merchandise received Type RF power Frequency range (MHz) 450~520 NX-840 M Choose the type of transceiver 450~520 NX-840H K 450~520 NX-840H(U) K A personal computer, programming interface (KPG-46A/46U), Transceiver programming and FPU (programming software) are required for programming. KCT-60 (Option)
Page 5 When using the KPG-46U, install the supplied CD (with driver software) in the computer. The KPG-46U driver runs under Win- dows XP, Vista, 7 or 8. The latest version of the USB driver is available for download from the following URL: http://www.kenwood.com/usb-com/ (This URL may change without notice.) (No.RA011<Rev.001>)1-5...
Page 6 2.2.4.2 Flow chart (Source transceiver) D-sub 15-pin Pin No. Name Molex 15-pin Pin No. Press [ ] key + Power ON for 2 seconds FNC1 FNC2 password* set? FNC3 * Read Authorization Shows PS FNC4 password FNC5 Enter password FNC6 Is entered password correct?
Page 7 2.3.3 Ignition Sense Cable (KCT-18: Option) Installation Procedure: Method B The KCT-18 is an optional cable for enabling the ignition func- (1) Remove the ACC. cap on the rear of the transceiver. tion. The ignition function lets you turn the transceiver power on (2) Connect the D-sub connector of the KCT-60 to the D-sub and off with the car ignition key.
Page 8 2.3.4.2 KES-5 2.3.6 Extended Function: COM Port 0 and COM Port 1 External speaker KES-5 can be installed for KCT-60. Location of COM Port 0 and COM Port 1 of the transceiver is shown below. Connection procedure (1) Remove the ACC. cap on the rear of the transceiver. COM Port 1 (2) Connect the D-sub connector of the KCT-60 to the D-sub 15-pin terminal of the transceiver.
Page 9 2.3.8 Changing of Signal Type (3) Dress the cable as shown in the figure. The cable needs to pass through one of two indentations located on the rear 2.3.8.1 Change signal input of D-SUB connector from DI to panel of the transceiver. The input (5pin) of D-SUB 15-pin connector is configured at the DI as the default value.
Page 10 CIRCUIT DESCRIPTION 2.4.1 Frequency Configuration The receiver utilizes double conversion. The first IF is 49.95MHz and the second IF is 450kHz. The first local oscillator signal is sup- plied from the PLL circuit. The PLL circuit in the transmitter generates the necessary frequencies. Figure 1 shows the frequencies. 49.95MHz IF SYSTEM 50.4MHz...
Page 11 2.4.2.4 AF Signal System The detection signal from FM IC (IC501) goes to the baseband IC (IC709) DISC input (pin 16) after pass through IC500 for character- izing the signal. • Analog signal The demodulated AF signal pass through IC709 with the signal processing and output at AUDIO (pin26) to the E-Vol before the Audio amplifier (IC719).
Page 12 2.4.3.3 APC Circuit The automatic transmission power control (APC) circuit detects part of a final amplifier output with a coupler circuit and applies a volt- age to IC301. IC301 compares the APC control voltage (APCC) generated by the baseband IC (IC709) and DC amplifier (IC503) with the detection output voltage.
Page 13 2.4.5 Control Circuit The MCU carries out the following tasks: (1) Controls the FM IC (IC501). (2) Controls the baseband IC (IC709). (3) Controls the PLL (IC2) & TX/RX outputs. (4) Controls IO expender through I2C level converter. (5) Controls the display unit. PLL IC C.DATA RSTN...
Page 14 2.4.5.3 Key Matrix Circuit < The front panel has function keys. Each of them is connected to KMO1 a cross point of a matrix of the KMI1 to KMO3 ports of the micro- CH UP processor. > KMO2 The KMO1 to KMO3 ports are always high, while the KMI1 to IC714 KMI3 ports are always low.
Page 15 2.4.6.3 NXDN Receiving • For Digital Data Mode: The demodulated signal from IC501 (Pin13) feed into baseband IC (Pin 16) for NXDN decoding. The decoded digital data will pass to MCU through C-BUS. MCU determines whether or not to output sound from speaker by check- ing if the data match.
Page 16 2.4.7 Power Supply Circuit • When the power switch on the display unit is pressed, the power port on the display unit which is connected pin 140 (POWKEY), goes low, then pin88 (SBC) goes high, Q718 turns on, SB SW (Q719) turns on and power (SB) is supplied to the transceiver. •...
Page 17 Port Name Function Port Name Function - 33MD - 33MD LSDO O Low-Speed Data Output MKEYI I DTMF MIC key input HSDO O High-Speed Data Output BUCNT2 O DTMF MIC buffer control O 33C Control PLL_UL I PLL Unlock Detect O 5C Control O SB Control SQIN...
Page 18 Port Name Function Ref. No. Part Name Description IC703 5V level shifter (TXDO/RTSO) 129 NC O No connection IC704 RS-232C driver 130 VSS - GND IC705 5V level shifter (TXD2) 131 VDD - 33MD IC706 MIC/AFO amplifier 132 NC O No connection IC709 Baseband IC 133 SWO...
Page 19 Ref. No. Part Name Description Ref. No. Part Name Description Q710 Transistor 9T switch D704~ Diode Surge protection D711 Q711 Transistor 5C control switch D712, Diode MIC AGC detection Q712 Transistor Overvoltage detect D713 Q713 Transistor Overvoltage detect D714, Diode RXD2 level shifter Q714, Speaker mute switch...
Page 20 Name Function Name Function J1(MIC Jack) J700 (D-SUB 15pin) 1 MBL Backlight of Microphone 1 SB Battery voltage DC supply DC 13.6V±15%,1.0A max 2 SB Battery voltage DC supply 2 IGN Ignition sens input,16.0V max 3 GND Ground 3 SP2 Speaker output 4 PTT PTT/ PC serial data from radio...
Page 21: Disassembly
SECTION 3 DISASSEMBLY Disassembly Procedure (4) To remove the speaker holder, first remove the two screws from the display PCB using a phillips screwdriver. (1) When removing the cabinet, first remove the two screws Then, insert a flat-head screwdriver under the tabs of the from the right and left with a phillips screwdriver.
Page 22 Note: (2) When mounting the panel assembly, pass the flat cable When you supply power to the TX-RX PCB after remov- through the hole of the chassis as shown below then con- ing the TX-RX PCB from the chassis, solder the positive nect the flat cable to connector of the panel assembly.
Page 23: Adjustment
SECTION 4 ADJUSTMENT Test Equipment Required for Alignment Test Equipment Major Specifications 1. Standard Signal Generator Frequency Range 100 to 520MHz (SSG) Modulation Frequency modulation and external modulation Output -127dBm/0.1µV to greater than -7dBm/100mV 2. Power Meter Input Impedance 50Ω Operation Frequency 100 to 520MHz Measuring Range...
Page 24 Frequency and Signaling Preparations for Tuning the Transceiver The transceiver has been adjusted for the frequencies shown in Before attempting to tune the transceiver, connect the unit to a the following table. When required, re-adjust them following the suitable power supply. adjustment procedure to obtain the frequencies you want in ac- Whenever the transmitter is tuned, the unit must be connected to tual operation.
Page 25 Common Section Item Condition Measurement Adjustment Specifications /Remarks Test- Unit Terminal Unit Parts Method equipment 1. Setting 1) Power supply voltage DC power supply terminal : 13.6V 2. Receive 1) Select each tab FPU Voltage level indi- 2.5 ±0.1V Assist voltage CH : Low cated in PC window CH : Low'...
Page 26 Item Condition Measurement Adjustment Specifications /Remarks Test- Unit Terminal Unit Parts Method equipment 4. Low 1) Test CH : Low, Low', Power meter FPU 5.0W ±0.1W Transmit Center, High', High Ammeter 4.0A or less Power ( 5 point ) 2) Baterry Terminal voltage : 13.6V 3) PTT ON ( Transmit ) 5.
Page 27 Item Condition Measurement Adjustment Specifications /Remarks Test- Unit Terminal Unit Parts Method equipment 12. MSK 1) Test CH : Center ( 1 point ) Deviation FPU 1.5kHz ±50Hz Deviation 2) Deviation meter filter Meter (Analog LPF : 15kHz Oscilloscope Narrow) HPF : OFF 3) PTT ON ( Transmit ) *Note 2:...
Page 28 Item Condition Measurement Adjustment Specifica- tions Test- Unit Terminal Unit Parts Method /Remarks equipment 5. High RSSI [Analog Narrow] FPU Press [Start], [Auto *Note 4 1) Test CH : Low, Low', Center, Oscilloscope tuning] High', High ( 5 point ) Audio 2) SSG output : -80dBm Analyzer...
Page 29: Troubleshooting
KPG-175D. "Service TX-RX unit" Data Note: The following data is written on the service TX-RX unit: • When a new printed circuit board is used, the KENWOOD ESN changes, as does the Transceiver Information dis- Data Type Description...
Page 30 MEMO...
Page 31: Printed Circuit Board
PRINTED CIRCUIT BOARD TX-RX UNIT (XC1-0010-11 (NX-840H(K), NX-840H(U)(K)), XC1-0010-22 (NX-840(M)) --- Component side view (J7C-0002-10) --- J701 C958 D-SUB C962 J700 R752 C956 CN713 CN709 CN710 C941 F700 CN703 CN704 CN705 R755 C949 C729 C727 C725 C723 C721 C720 D709...
Page 32 TX-RX UNIT (XC1-0010-11 (NX-840H(K), NX-840H(U)(K)), XC1-0010-22 (NX-840(M)) --- Foil side view (J7C-0002-10) --- D715 R789 C965 Q703 C745 R786 R356 R741 D714 C947 Q702 C950 C364 C952 C955 C769 C773 C361 C360 C774 C770 C772 C771 TH302 R774 C775 C767...
Page 33 A-1C ADDRESS TABLE OF BOARD PARTS Side Y axis Each address may have an address error by one interval. X axis REF.NO. LOCATION REF.NO. LOCATION REF.NO. LOCATION REF.NO. LOCATION REF.NO. LOCATION REF.NO. LOCATION REF.NO. LOCATION REF.NO. LOCATION REF.NO. LOCATION REF.NO. LOCATION REF.NO. LOCATION REF.NO. LOCATION REF.NO. LOCATION REF.NO. LOCATION REF.NO. LOCATION REF.NO. LOCATION REF.NO. LOCATION Q719 A- 1C B- 2B...
Page 34 DISPLAY UNIT (X54-3890-20) --- Component side view (J79-0249-29) --- ADDRESS TABLE OF BOARD PARTS Each address may have an address error by one interval. POWER A-1C Side Y axis X axis REF.NO. LOCATION REF.NO. LOCATION REF.NO. LOCATION B- 2B B- 1A B- 4B B- 2A B- 4B...
Page 35: Schematic Diagram
SCHEMATIC DIAGRAM TX-RX UNIT (1/2) (XC1-0010-11 (NX-840H(K), NX-840H(U)(K)), XC1-0010-22 (NX-840(M)) RX VCO R:5.27V MCH3914(7)-H L92-0443-05 (92) (14) R:1.71V 270n 0.3p 1SV325F DRIVE AMP T:8.86V 0.01u CV(A) Q300 (-92) (-92) 3.31V TX/RX BAND SWITCH R:0V BUFFER AMP RD00HVS1-T113 L303 L305 C313 T:3.36V...
Page 36 TX-RX UNIT (2/2) (XC1-0010-11 (NX-840H(K), NX-840H(U)(K)), XC1-0010-22 (NX-840(M)) D309 D310 D501 L300 L301 L302 L303 L304 L305 L310 L312 L313 L314 L316 L317 L318 L503 L504 L506 L507 UHF(K) 0-11 1SV325F 1SV325F 1SV305F 6.8n 270n 270n 220n 220n 220n 220n...
Page 37 DISPLAY UNIT (X54-3890-20) KEY BACKLIT HOOK 4.06V 13.53V KRA225S 5.6k B30-2337-05 B30-2337-05 4.06V 5.6k B30-2337-05 B30-2337-05 1.90V KRC102S-P 6.8k HDSP-521A B30-2337-05 4.94V LEDM RLED GLED BLED KMO1 KMO2 KMO3 TO TX-RX 2SC3928A KMI1 UNIT 1/2 KMI2 CN700 KMI3 RK74HB1J102J L92-0138-05 LEDI LECE LECL...
Page 38: Level Diagram
LEVEL DIAGRAM Receiver Section RF (Center Frequency) IF_1 (49.95MHz) IF_2 (450kHz) AF Frequency (1kHz) 242mVrms N: -116.5dBm 84mVrms 83mVrms 82mVrms N: -100dBm 0.100Vrms N: -120 dBm N: - 103dBm N: -101.5dBm N: - 119.5dBm 281mVrms 4 Vrms 4.59 Vrms IF amplifier FMIC Baseband IC Baseband IC...
Page 39: Block Diagram
BLOCK DIAGRAM DISPLAY UNIT X54-389 TX/RX UNIT XC1-001 D305,306 : L407CDB Q300 IC300 POWER 9T 9R 450-520MHz D309,D310 : 2SC5636 MCH3914(7)-H 2SC5108(Y)F 2SC5108(Y)F RD00HVS1-T113 RA60H44521101 COUPPLER TX/RX DRIVE POWER POWER BUFF MODULE KMO1 AK1541 PLL_LE LV/C KRX102U D16,17 LOOP <B PLL_CLK RN142S Filter...
Page 40 MEMO...
Page 41: Parts List
PARTS LIST [NX-840H,NX-840H(U),NX-840] * SAFETY PRECAUTION Parts identified by the symbol are critical for safety. Replace only with specified part numbers. * BEWARE OF BOGUS PARTS Parts that do not meet specifications may cause trouble in regard to safety and performance.
Page 42 Exploded view of general assembly and parts list Block No.M1MM J700 J701 IC705 IC301 R374 TX-RX UNIT<02> DISPLAY UNIT<01> 3-2(No.RA011<Rev.001>)
Page 43 General assembly Block No. [M][1][M][M]  Symbol No. Part No. Part Name Description Local A02-4073-21 PLASTIC CABINET A6A-0004-00 PANEL ASSY B09-0732-03 CAP(D-SUB) B4D-0003-00 BADGE B10-2794-03 FRONT GLASS E04-0167-15 RF COAXIAL RECEPTACLE(M) E23-1346-04 GROUND TERMINAL E30-7684-25 DC CORD E37-1461-05 FLAT CABLE(30P PANEL) G53-1643-04 PACKING(DC CORD) G53-1662-04...
Page 44: Electrical Parts List
RK74HB1J102J CHIP-COM 1.0K J 1/16W 2SC3928A TRANSISTOR MODULAR JACK 2SC3928A TRANSISTOR LTA014EEBFS8 TRANSISTOR LTA014EEBFS8 TRANSISTOR TX-RX UNIT 2SC3928A TRANSISTOR XC1-0010-11 (NX-840H(K), NX-840H(U)(K)) B30-2337-05 (YELLOW) B30-2337-05 (YELLOW) XC1-0010-22 (NX-840(M)) B30-2337-05 (YELLOW) B30-2337-05 (YELLOW) Block No. [0][2] B30-2337-05 (YELLOW) DA221 DIODE  Symbol No.
Page 45  Symbol No. Part No. Part Name Description Local  Symbol No. Part No. Part Name Description Local Q506 3SK318 CK73HB1H271K C CAPACITOR 270PF K Q700 2SK1824-A CK73HB1H103K C CAPACITOR 0.010UF K Q701 2SC4919-S TRANSISTOR CK73HB1E103K C CAPACITOR 0.010UF K Q702 LTC014TEBFS8 TRANSISTOR...
Page 46  Symbol No. Part No. Part Name Description Local  Symbol No. Part No. Part Name Description Local C311 CC73HCH1H1R5B C CAPACITOR 1.5PF B C535 CK73HB0J225K C CAPACITOR 2.2UF K C312 CK73HB1E223K C CAPACITOR 0.022UF K C536 CK73GB1A105K C CAPACITOR 1.0UF K C313 CC73GCH1H271J C CAPACITOR...
Page 47  Symbol No. Part No. Part Name Description Local  Symbol No. Part No. Part Name Description Local C720 CK73HB1H471K C CAPACITOR 470PF K C843 CK73HB1A104K C CAPACITOR 0.10UF K C721 CK73HB1H471K C CAPACITOR 470PF K C844 CK73HB1H102K C CAPACITOR 1000PF K C722 CC73HCH1H101J C CAPACITOR...
Page 48  Symbol No. Part No. Part Name Description Local  Symbol No. Part No. Part Name Description Local C941 CK73EB1E106K C CAPACITOR 10UF K RK73FB2B102J MG RESISTOR 1.0K J 1/8W C942 CK73HB1H102K C CAPACITOR 1000PF K RK73HB1J220J MG RESISTOR 22 J 1/16W C944 CK73FB1E225K C CAPACITOR...
Page 49  Symbol No. Part No. Part Name Description Local  Symbol No. Part No. Part Name Description Local R509 RK73HB1J123J MG RESISTOR 12K J 1/16W R704 RK73HB1J000J MG RESISTOR 0.0 J 1/16W R510 RK73HB1J104J MG RESISTOR 100K J 1/16W R705 RK73HB1J000J MG RESISTOR 0.0 J 1/16W...
Page 50  Symbol No. Part No. Part Name Description Local  Symbol No. Part No. Part Name Description Local R804 RK73HB1J104J MG RESISTOR 100K J 1/16W R907 RK73HB1J100J MG RESISTOR 10 J 1/16W R805 RK73GB2A104J MG RESISTOR 100K J 1/10W R908 RK73HB1J473J MG RESISTOR 47K J 1/16W...
Page 51  Symbol No. Part No. Part Name Description Local  Symbol No. Part No. Part Name Description Local R998 RK73HB1J101J MG RESISTOR 100 J 1/16W CP707 RK75HA1J102J CHIP-COM 1.0K J 1/16W R999 RK73HB1J101J MG RESISTOR 100 J 1/16W CP708 RK74HA1J102J CHIP-COM 1.0K J 1/16W F700...
Page 52 Packing materials and accessories parts list Block No.M2MM Packing and accessories Block No. [M][2][M][M]  Symbol No. Part No. Part Name Description Local B5A-0031-10 INSTRUCTION MANUAL HK,HUK B5A-0030-10 INSTRUCTION MANUAL E30-7523-55 DC CORD ASSY ACCESSORY F52-0024-05 FUSE(BLADE TYPE)15A ACCESSORY (x2) HK,HUK F52-0023-05 FUSE(BLADE TYPE)10A ACCESSORY (x2)
Page 53 MEMO...
Page 54 JVC KENWOOD Corporation Communications Equipment Div (No.RA011<Rev.001>) Printed in Japan...

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Kenwood NX-840H Service Manual

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