Kenwood TK-785 Service Manual

Hide thumbs Also See for TK-785:

Instruction manual (20 pages)

Table of Contents

Quick Links

Summary of Contents for Kenwood TK-785

Page 1: Table Of Contents
VHF FM TRANSCEIVER TK-785 SERVICE MANUAL © 2000-6 PRINTED IN JAPAN B51-8534-00 ( N ) 616 Panel assy Cabinet (Upper) Key top (A62-0642-03) (A01-2165-13) (K29-5422-02) Cabinet (Lower) Modular jack (A01-2166-13) (E08-0877-05) CONTENTS GENERAL ..............2 TERMINAL FUNCTION ......... 51 OPERATING FEATURES ......... 3 PC BOARD VIEWS REALIGNMENT ............
Page 2: General
TK-785 GENERAL 3. PLANNING THE INSTALLATION INTRODUCTION 3-1. General SCOPE OF THIS MANUAL Inspect the vehicle and determine how and where the This manual is intended for use by experienced techni- radio antenna and accessories will be mounted. cians familiar with similar types of commercial grade com- Plan cable runs for protection against pinching or crush- munications equipment.
Page 3: Operating Features
Control station. The antenna system selection depends 1. Transceiver Controls and Indicators (Fig. 1) on many factors and is beyond the scope of this manual. Your KENWOOD dealer can help you select an antenna sys- 1-1. The Basics tem that will best serve your particular needs.
Page 4: Realignment
TK-785 OPERATING FEATURES / REALIGNMENT C key (Default setting : None) REALIGNMENT Press to activate its auxiliary function below. Also press to scroll left while viewing stack entries. 1. Modes key (Default setting : None) Press to activate its auxiliary function below. Also press User mode to scroll right while viewing stack entries.
Page 5 6. Firmware Programming Mode model type, when it is written into the flash memory. 6-1. Preface • Change the TK-785 to PC mode, then attach the interface Flash memory is mounted on the TK-785. This allows the cable. TK-785 to be upgraded when new features are released in the future.
Page 6: Installation
TK-785 REALIGNMENT / INSTALLATION Notes : INSTALLATION • This mode cannot be entered if the Firmware program- ming mode is set to Disable in the Programming soft- 1. Accessory Connection Cable ware (KPG-62D). • When programming the firmware, it is recommend to...
Page 7 TK-785 INSTALLATION 1-2. KCT-19 Accessory Port Function 1-3. Data Equipment Connection The jumpers must be set to either one for each function. No. (A) No. (B,C,D,E) Name Function Note Otherwise, the radio will not work properly. No function. Microphone ground.
Page 8 TK-785 INSTALLATION 2. Accessory Terminal (TX-RX Unit) 2-1. External Connector Accessory Terminal Method Connector Function name O Detect signal output. (Output level : 250mVrms; standard modulation) TX-RX unit (A/2) No function. Foil side view Ignition sense input. External modulation signal input.
Page 9 TK-785 INSTALLATION 3. Optional Board Terminal Terminal is for mounting the option board are provided at the control and TX-RX unit. The table below shows the cor- respondence between the board and terminals. Disconnect DEO RD2 5C C4 C3 R529 and R571 in control unit when the scrambler board is attached.
Page 10 Modify the transceiver as follows to turn the power or • Modification the Horn Alert or Manual Relay function on and off with the 1. Remove the upper half of the case of the TK-785. ignition key. 2. Remove R529 and R571 on the Control unit (X57-614 B/2 1.
Page 11 TK-785 INSTALLATION Scrambler board TK-785 Code 4 (C4) (TX-RX PCB) TXAI Code 3 (C3) (TX-RX PCB) TXAO Code 2 (C2) (TX-RX PCB) Code 1 (C1) (TX-RX PCB) Control unit (B/2) ( ) : PCB silk name Foil side view R571...
Page 12 Fig. 11 7. Fitting the Control Panel Upside Down The TK-785 control panel can be fitted upside down, so the transceiver can be mounted with its internal speaker (in the upper half of the case) facing down in your car.
Page 13: External Speaker
TK-785 INSTALLATION 2. Fold the flat cable ( ) in the opposite direction ( 8. External Speaker 3. Rotate the control section ( ) 180 degrees ( 8-1. KES-3 : Option 4. Insert the flat cable into the control section connector, The KES-3 is an external speaker for the 3.5-mm-diam-...
Page 14: Circuit Description
TK-785 CIRCUIT DESCRIPTION The signal passes through the BPF and is down-con- Frequency Configuration verted with the first local signal by IC202 to produce the first The TX-RX unit incorporates a VCO, based on a fractional IF signal of 44.85 MHz. The first local signal passes through N type PLL synthesizer system, that has 12.5kHz.
Page 15 DTMF VCO/PLL Circuit The TK-785 has a VCO for the transmitter and a VCO for FIg. 3 AF signal system the receiver in a sub-unit (A1). They are housed in a solid shielded case and connected to the TX-RX unit through CN101.
Page 16 TK-785 CIRCUIT DESCRIPTION Since a signal output from Q106 is input to the PLL IC, it nal is compared with the reference frequency which is out- passes through CN101 and buffer amplifier (Q300) and goes put from the VCXO (X1). VCXO provides 16.8MHz, 2.5ppm to the PLL IC (IC300).
Page 17 TK-785 CIRCUIT DESCRIPTION APC Circuit Control Circuit The automatic transmission power control (APC) circuit The CPU carries out the following tasks: detects part of a power module output with a diode (D27, 1) Controls the shift register (IC7, IC8, IC508) AF MUTE, T/R D30) and applies a voltage to Q21.
Page 18 Key Matrix Circuit Fig. 12 Encode The TK-785 front panel has ten keys. Each of them is connected to a cross point of a matrix of the KEY1 to KEY7 Decode ports of the microprocessor. The KEY5 to KEY7 ports are always high, while the KEY1 to KEY4 ports are always low.
Page 19 TK-785 CIRCUIT DESCRIPTION D/A Converter Power Supply Circuit The D/A converter (IC5) is used to adjust TONE and MO When the POWER switch on the control unit is pressed, modulation, beep, AF volume, TV voltage, FC reference volt- the PSW signal goes low. This signal is inverted by Q26 and age, and PC POWER CONTROL voltage level.
Page 20: Semiconductor Data
TK-785 SEMICONDUCTOR DATA Microprocessor : 30620M8-394GP (TX-RX Unit IC511) Terminal function Pin No. Name Function Pin No. Name Function LSDOUT Low speed data output. RFCLK Common clock output. (TX-RX unit) HSDOUT High speed data output. – Not used. HSDIN High speed data input.
Page 21 TK-785 SEMICONDUCTOR DATA Terminal function (TX-RX unit IC7) Shift Register : BU4094BCFV Pin No. Port Name Function Terminal function (TX-RX unit IC508) Strobe Pin No. Port Name Function Data Strobe Clock Data HORN Horn alert. H : ON, L : OFF / Clock Auxiliary A.
Page 22: Description Of Components
TK-785 DESCRIPTION OF COMPONENTS TX-RX Unit (X57-6142-71) (A/2) : K,E Ref. No. Use / Function Operation / Condition Ref. No. Use / Function Operation / Condition W/N switch No function DC amp FC, TCXO control W/N switch No function DET amp...
Page 23 TK-785 DESCRIPTION OF COMPONENTS TX-RX Unit (X57-6150-21) (A/2) : M Ref. No. Use / Function Operation / Condition Ref. No. Use / Function Operation / Condition Q23,24 W/N switch No function DC amp FC, TCXO control TOF switch Active while Q22 is on...
Page 24 TK-785 DESCRIPTION OF COMPONENTS Control Unit (X57-6142-71) (B/2) : K,E Ref. No. Use / Function Operation / Condition (X57-6150-21) (B/2) : M D512~517 Key backlight Active while KBLC is “H” Ref. No. Use / Function Operation / Condition D518 Current regulation Key backlight...
Page 25: Parts List
TK-785 PARTS LIST New Parts. indicates safety critical components. Parts without Parts No. are not supplied. Les articles non mentionnes dans le Parts No. ne sont pas fournis. Teile ohne Parts No. werden nicht geliefert. TK-785 TX-RX UNIT (X57-6142-71) : K,E...
Page 26 TK-785 PARTS LIST TX-RX UNIT (X57-6142-71) : K,E Desti- Desti- Ref. No. Address Parts No. Description Ref. No. Address Parts No. Description parts nation parts nation C92-0044-05 CHIP-ELE 47UF 10WV C151 CC73GCH1H820J CHIP C 82PF CK73GB1H102K CHIP C 1000PF C153...
Page 27 TK-785 PARTS LIST TX-RX UNIT (X57-6142-71) : K,E Desti- Desti- Ref. No. Address Parts No. Description Ref. No. Address Parts No. Description parts nation parts nation C266 CC73GCH1H150J CHIP C 15PF C525 CK73GB1H103K CHIP C 0.010UF C267 CC73GCH1H220J CHIP C...
Page 28 TK-785 PARTS LIST TX-RX UNIT (X57-6142-71) : K,E Desti- Desti- Ref. No. Address Parts No. Description Ref. No. Address Parts No. Description parts nation parts nation C607 CK73GB1H103K CHIP C 0.010UF L220 L40-1888-67 SMALL FIXED INDUCTOR (180NH) C608 CK73GB1H392K CHIP C...
Page 29 TK-785 PARTS LIST TX-RX UNIT (X57-6142-71) : K,E Desti- Desti- Ref. No. Address Parts No. Description Ref. No. Address Parts No. Description parts nation parts nation RK73GB1J153J CHIP R 1/16W R144 RK73GB1J223J CHIP R 1/16W RK73GB1J103J CHIP R 1/16W R145...
Page 30 TK-785 PARTS LIST TX-RX UNIT (X57-6142-71) : K,E Desti- Desti- Ref. No. Address Parts No. Description Ref. No. Address Parts No. Description parts nation parts nation R304 R92-1252-05 CHIP R 0 OHM R535 RK73GB1J155J CHIP R 1.5M 1/16W R305 RK73GB1J103J...
Page 31 TK-785 PARTS LIST TX-RX UNIT (X57-6142-71) : K,E Desti- Desti- Ref. No. Address Parts No. Description Ref. No. Address Parts No. Description parts nation parts nation R633 R92-1368-05 CHIP R 0 OHM DA204U DIODE R634 RK73HB1J102J CHIP R 1.0K 1/16W...
Page 32 TK-785 PARTS LIST TX-RX UNIT (X57-6142-71) : K,E TX-RX UNIT (X57-6150-21) : M Desti- Desti- Ref. No. Address Parts No. Description Ref. No. Address Parts No. Description parts nation parts nation 2SK1824 CC73GCH1H470J CHIP C 47PF Q2,3 2SC2412K(S) TRANSISTOR C92-0628-05...
Page 33 TK-785 PARTS LIST TX-RX UNIT (X57-6150-21) : M Desti- Desti- Ref. No. Address Parts No. Description Ref. No. Address Parts No. Description parts nation parts nation C101 CK73GB1H102K CHIP C 1000PF C208 CC73GCH1H270J CHIP C 27PF C102 CC73GCH1H270J CHIP C...
Page 34 TK-785 PARTS LIST TX-RX UNIT (X57-6150-21) : M Desti- Desti- Ref. No. Address Parts No. Description Ref. No. Address Parts No. Description parts nation parts nation C315,316 CK73GB1C104K CHIP C 0.10UF C553 CK73GB1H472K CHIP C 4700PF C317 CK73GB1H102K CHIP C...
Page 35 TK-785 PARTS LIST TX-RX UNIT (X57-6150-21) : M Desti- Desti- Ref. No. Address Parts No. Description Ref. No. Address Parts No. Description parts nation parts nation C721-723 CC73GCH1H221J CHIP C 220PF R6,7 R92-1252-05 CHIP R 0 OHM C724 CK73GB1H682K CHIP C...
Page 36 TK-785 PARTS LIST TX-RX UNIT (X57-6150-21) : M Desti- Desti- Ref. No. Address Parts No. Description Ref. No. Address Parts No. Description parts nation parts nation RK73GB1J102J CHIP R 1.0K 1/16W R176 R92-0670-05 CHIP R 0 OHM R92-1252-05 CHIP R...
Page 37 TK-785 PARTS LIST TX-RX UNIT (X57-6150-21) : M Desti- Desti- Ref. No. Address Parts No. Description Ref. No. Address Parts No. Description parts nation parts nation R408 R92-1252-05 CHIP R 0 OHM R553 RK73GB1J102J CHIP R 1.0K 1/16W R411 RK73GB1J472J CHIP R 4.7K...
Page 38 TK-785 PARTS LIST TX-RX UNIT (X57-6150-21) : M Desti- Desti- Ref. No. Address Parts No. Description Ref. No. Address Parts No. Description parts nation parts nation R650-652 R92-1368-05 CHIP R 0 OHM MA742 DIODE R653,654 RK73HB1J102J CHIP R 1.0K 1/16W...
Page 39 TK-785 PARTS LIST TX-RX UNIT (X57-6150-21) : M PLL/VCO (X58-471X-XX) Desti- Desti- Ref. No. Address Parts No. Description Ref. No. Address Parts No. Description parts nation parts nation 2SC2412K(S) TRANSISTOR C127 CK73GB1H102K CHIP C 1000PF 2SK1824 C129 CK73GB1H102K CHIP C...
Page 40: Exploded View
TK-785 EXPLODED VIEW Parts with the exploded numbers larger than 700 are not supplied.
Page 41: Packing
TK-785 PACKING (K,M) 38 Protection bag 39 Protection bag (H25-0103-04) (H25-0720-04) 5 Cap (B09-0235-05) 12 DC cord (E30-3339-05) 23 Fuse (F51-0016-05) 43 Bracket (J29-0627-23) 37 Inner packing case (H12-1391-03) 47 Screw set (N99-0395-05) 36 Polystyrene foamed fixture (H10-6619-12) 704 Warranty card : K...
Page 42 TK-785 PACKING (E) 51 MIC assy 39 Protection bag 12 DC cord (H25-0720-04) (T91-0624-05) 5 Cap (E30-3339-05) (B09-0235-05) 23 Fuse (F51-0016-05) 43 Bracket (J29-0627-23) 37 Inner packing case (H12-1391-03) 42 MIC hanger (J19-1584-05) 47 Screw set 36 Polystyrene foamed fixture...
Page 43: Adjustment
TK-785 ADJUSTMENT Frequency and Signalling Test Mode The set has been adjusted for the frequencies shown in Test Mode Operating Features the following table. When required, re-adjust them follow- This transceiver has a test mode. To enter test mode, ing the adjustment procedure to obtain the frequencies you press [B] key and turn power on.
Page 44 TK-785 ADJUSTMENT • Tuning flow Press [A], now in tuning mode. Use [ C] button to write tuning data through tuning modes, and [System Up/Down] to adjust tuning requirements (1 to 256 appears on LCD). FREQ xxx Use [D ] button to select the adjustment item through tuning modes.
Page 45 TK-785 ADJUSTMENT Test Equipment Required for Alignment Test Equipment Major Specifications 1. Standard Signal Generator Frequency Range 217 to 235MHz (K,E), 250 to 270MHz (M) (SSG) Modulation Frequency modulation and external modulation Output –127dBm/0.1µV to greater than –7dBm/100mV 2. Power Meter Input Impedance 50Ω...
Page 46 EEPROM, is stored in memory. When parts are changed, readjust the transceiver. Repair Jig (Chassis) TX-RX UNIT (A/2) Use jig (Part No. : A10-4010-02) for repairing the TK-785. The jig facilitates the voltage check when the voltage on the component side TX-RX unit is checked during repairs. L203...
Page 47 TK-785 ADJUSTMENT Receiver Section Measurement Adjustment Item Condition Specifications/Remarks Test- Unit Terminal Unit Parts Method equipment 1. Discriminator 1) Set test mode Rear TX-RX L6 AF output voltage CH : CH1 - Sig1 panel (A/2) maximum. SSG output : –53dBm AF VTVM AF : 1.4V/4Ω...
Page 48 TK-785 ADJUSTMENT Measurement Adjustment Item Condition Specifications/Remarks Test- Unit Terminal Unit Parts Method equipment 5. RSSI (High) 1) Set test mode Rear Writing values only. Select “L HRSI” in tuning mode. panel SSG freq’ : 217.05MHz K,E AF VTVM : 250.05MHz M Distortion (EXT.SP)
Page 49 TK-785 ADJUSTMENT Measurement Adjustment Item Condition Specifications/Remarks Test- Unit Terminal Unit Parts Method equipment ± 1.0W 3. High power 1) Set test mode Power meter Rear 10.0W K Select “HPOW” in tuning mode. F. counter panel 15.0W E “L HPOW”...
Page 50 TK-785 ADJUSTMENT Measurement Adjustment Item Condition Specifications/Remarks Test- Unit Terminal Unit Parts Method equipment ± 1.5kHz±0.05kHz 8. MIC 1) Set test mode Power meter Rear Check seisitivity CH : CH1 - Sig1 Deviation panel check AG : 1kHz/4mV meter PTT : ON Oscilloscope ±...
Page 51: Terminal Function
TK-785 TERMINAL FUNCTION CN7 (TX-RX Unit) ← → CN502 (Control Unit) CN101 (VCO) ← → TX-RX Unit Pin No. Name Function Pin No. Name Function No function. Switched transmit input. H : Transmit TX/RX switch. H : Receive RF output.
Page 52: Pc Board Views
TK-785 TK-785 PC BOARD VIEWS PLL/VCO (X58-471X-XX) 0-21 : M 2-71 : K,E Component side view J72-0732-02 CN101 L110 L103 R101 C122 L105 C134 C104 R105 L106 C136 R116 Q105 C127 R107 Q106 C138 R108 Q101 R109 C114 R103 C135...
Page 53: Tx-Rx Unit (X57-6142-71) (A/2)
TK-785 K,E PC BOARD VIEW TX-RX UNIT (X57-6142-71) (A/2) Component side view Ref. No. Address Ref. No. Address Ref. No. Address Ref. No. Address Ref. No. Address I C5 Q403 IC10 IC11 D206 Component side IC400 IC14 Q300 D207 Pattern 1...
Page 54 TK-785 K,E PC BOARD VIEW TX-RX UNIT (X57-6142-71) (A/2) Foil side view Ref. No. Address Ref. No. Address Ref. No. Address Ref. No. Address Ref. No. Address Ref. No. Address Ref. No. Address IC13 IC15 IC201 Component side IC400 D209...
Page 55 TK-785 K,E PC BOARD VIEW TX-RX UNIT (X57-6142-71) (A/2) Component side view + Foil side Ref. No. Address Ref. No. Address Ref. No. Address Ref. No. Address Ref. No. Address Ref. No. Address Ref. No. Address Ref. No. Address Ref. No. Address...
Page 56: Tx-Rx Unit (X57-6142-71) (B/2)
TK-785 K,E PC BOARD VIEWS TX-RX UNIT (X57-6142-71) (B/2) Component side view J72-0724-12 B/2 D512 R514 D517 R710 C712 R517 R510 C527 C710 C518 C583 R526 R713 L507 IC710 R525 R682 IC502 C524 R572 D511 IC501 IC508 C592 R531 R714...
Page 57 TK-785 K,E PC BOARD VIEWS TX-RX UNIT (X57-6142-71) (B/2) Component side view + Foil side J72-0724-12 B/2 D512 R520 R514 D517 R710 C607 C712 R517 MPTT C516 R518 R510 C515 C527 C710 C518 C583 R525 RXAO R521 R680 R526 R713...
Page 58: Tx-Rx Unit (X57-6150-21) (A/2)
TK-785 M PC BOARD VIEW TX-RX UNIT (X57-6150-21) (A/2) Component side view Ref. No. Address Ref. No. Address Ref. No. Address Ref. No. Address Ref. No. Address Q203 D205 IC10 Q300 D206 IC11 Q301 D211 IC14 Q302 D212 Component side...
Page 59 TK-785 M PC BOARD VIEW TX-RX UNIT (X57-6150-21) (A/2) Foil side view Ref. No. Address Ref. No. Address Ref. No. Address Ref. No. Address Ref. No. Address Ref. No. Address Ref. No. Address IC13 Q26 10C Q205 D17 13D IC15...
Page 60 TK-785 M Ref. No. Address Ref. No. Address Ref. No. Address Ref. No. Address Ref. No. Address Ref. No. Address Ref. No. Address Ref. No. Address PC BOARD VIEW IC14 Q203 D203 TX-RX UNIT (X57-6150-21) (A/2) Component side view + Foil side...
Page 61: Tx-Rx Unit (X57-6150-21) (B/2)
TK-785 M PC BOARD VIEWS TX-RX UNIT (X57-6150-21) (B/2) Component side view J72-0725-12 B/2 D512 R514 D517 R710 C712 R517 R510 C527 C710 C518 C583 R526 R713 L507 IC710 R525 R682 IC502 C524 R572 D511 IC501 IC508 C592 R531 R714...
Page 62 TK-785 M PC BOARD VIEW TX-RX UNIT (X57-6150-21) (B/2) Component side view + Foil side J72-0725-12 B/2 D512 R520 R514 D517 R710 C607 C712 R517 MPTT C516 R518 R510 C515 C527 C710 C518 C583 R525 RXAO R680 R521 R526 R713...
Page 63: Schematic Diagram
TK-785 K,E SCHEMATIC DIAGRAM Note : Components marked with a dot (·) are parts of patterun 1.
Page 64 TK-785 K,E Note : Components marked with a dot (·) are parts of patterun 1. SCHEMATIC DIAGRAM...
Page 65 TK-785 M SCHEMATIC DIAGRAM Note : Components marked with a dot (·) are parts of patterun 1.
Page 66 TK-785 M Note : Components marked with a dot (·) are parts of patterun 1. SCHEMATIC DIAGRAM...
Page 67: Level Diagram
TK-785 TK-785 LEVEL DIAGRAM (K,E) Receiver Section –88.0dBm –94.5dBm –118.0dBm –121.0dBm –109.0dBm –106.5dBm –110.0dBm –120.5dBm 62mVrms 30mVrms 820mVrms 820mVrms 16mVrms 0.45Vrms SG input level for 12dB SINAD are obtained measured by AF VTVM connecting SG to each point via a 0.01µF capacitor.
Page 68 TK-785 TK-785 LEVEL DIAGRAM (M) Receiver Section –88.0dBm –95.0dBm –118.0dBm –122.0dBm –116.0dBm –116.0dBm –108.0dBm –121.0dBm –109.0dBm 62mVrms 30mVrms 820mVrms 820mVrms 16mVrms 0.45Vrms SG input level for 12dB SINAD are obtained measured by AF VTVM connecting SG to each point via a 0.01µF capacitor.
Page 69: Block Diagram
TK-785 TK-785 TK-785 BLOCK DIAGRAM (K,E)
Page 70 TK-785 TK-785 TK-785 BLOCK DIAGRAM (M)
Page 71: Specifications
TK-785 SPECIFICATIONS GENERAL Frequency Range ........ TX : 218 to 235MHz (K,E) RX : 217 to 235MHz (K,E) 250 to 270MHz (M) Number of Channels ......Trunking mode : Maximum 1023 channels Conventional mode : Maximum 32 channels Channel Spacing ......... 12.5kHz Input Voltage ........
Page 72 Mechelsesteenweg 418 B-1930 Zaventem, Belgium KENWOOD ELECTRONICS FRANCE S.A. 13, Boulevard Ney, 75018 Paris, France KENWOOD ELECTRONICS U.K. LIMITED KENWOOD House, Dwight Road, Watford, Herts., WD1 8EB United Kingdom KENWOOD ELECTRONICS EUROPE B.V. Amsterdamseweg 37, 1422 AC Uithoorn, The Netherlands KENWOOD ELECTRONICS ITALIA S.p.A.

Kenwood TK-785 Service Manual

Quick Links

Related Manuals for Kenwood TK-785

Summary of Contents for Kenwood TK-785

Table of Contents