KENWOOD TK785 - Service Manual Immediate Download

B51-8534-00 (N) 616

VHF FM TRANSCEIVER

TK-785

SERVICE MANUAL

GENERAL ................................................................. 2

OPERATING FEATURES ......................................... 3

REALIGNMENT ........................................................ 4

INSTALLATION ........................................................ 6

CIRCUIT DESCRIPTION ......................................... 14

SEMICONDUCTOR DATA ..................................... 20

DESCRIPTION OF COMPONENTS ....................... 22

PARTS LIST ............................................................ 25

EXPLODED VIEW .................................................. 40

PACKING ................................................................ 41

ADJUSTMENT ....................................................... 43

TERMINAL FUNCTION ......................................... 51

PC BOARD VIEWS

PLL/VCO (X58-471X-XX) .................................. 52

TX-RX UNIT (X57-6142-71) (A/2)..................... 53

TX-RX UNIT (X57-6142-71) (B/2) ..................... 59

TX-RX UNIT (X57-6150-21) (A/2)..................... 63

TX-RX UNIT (X57-6150-21) (B/2) ..................... 69

SCHEMATIC DIAGRAM ........................................ 73

LEVEL DIAGRAM ................................................... 89

BLOCK DIAGRAM .................................................. 93

SPECIFICATIONS ................................................... 99

CONTENTS

Cabinet (Upper)

(A01-2165-13)

Cabinet (Lower)

(A01-2166-13)

Modular jack

(E08-0877-05)

Panel assy

(A62-0642-03)

Key top

(K29-5422-02)

TK-785

GENERAL

INTRODUCTION

SCOPE OF THIS MANUAL

This manual is intended for use by experienced techni-

cians familiar with similar types of commercial grade com-

munications equipment. It contains all required service in-

formation for the equipment and is current as of the publica-

tion data. Changes which may occur after publication are

covered by either Service Bulletins or Manual Revisions.

These are issued as required.

ORDERING REPLACEMENT PARTS

When ordering replacement parts or equipment informa-

tion, the full part identification number should be included.

This applies to all parts : components, kits, or chassis. If the

part number is not known, include the chassis or kit number

of which it is a part, and a sufficient description of the re-

quired component for proper identification.

PERSONNEL SAFETY

The following precautions are recommended for person-

nel safety :

· DO NOT transmit if someone is within two feet (0.6

meter) of the antenna.

· DO NOT transmit until all RF connectors are verified se-

cure and any open connectors are properly terminated.

· SHUT OFF and DO NOT operate this equipment near

electrical blasting caps or in an explosive atmosphere.

· All equipment should be properly grounded before

power-up for safe operation.

· This equipment should be serviced by a qualified techni-

cian only.

PRE-INSTALLATION CONSIDERNATIONS

1. UNPACKING

Unpack the radio from its shipping container and check

for accessory items. If any item is missing, please contact

KENWOOD immediately.

2. PRE-INSTALLATION CHECKOUT

2-1. Introduction

Each radio is adjusted and tested before shipment. How-

ever, it is recommended that receiver and transmitter op-

eration be checked for proper operation before installation.

2-2. Testing

The radio should be tested complete with all cabling and

accessories as they will be connected in the final installa-

tion. Transmitter frequency, deviation, and power output

should be checked, as should receiver sensitivity, squelch

operation, and audio output. QT equipment operation

should be verified.

3. PLANNING THE INSTALLATION

3-1. General

Inspect the vehicle and determine how and where the

radio antenna and accessories will be mounted.

Plan cable runs for protection against pinching or crush-

ing wiring, and radio installation to prevent overheating.

3-2. Antenna

The favored location for an antenna is in the center of a

large, flat conductive area, usually at the roof center. The

trunk lid is preferred, bond the trunk lid and vehicle chassis

using ground straps to ensure the lid is at chassis ground.

3-3. Radio

The universal mount bracket allows the radio to be

mounted in a variety of ways. Be sure the mounting surface

is adequate to support the radio's weight. Allow sufficient

space around the radio for air cooling. Position the radio

close enough to the vehicle operator to permit easy access

to the controls when driving.

3-4. DC Power and wiring

1. This radio may be installed in negative ground electrical

systems only. Reverse polarity will cause the cable fuse

to blow. Check the vehicle ground polarity before installa-

tion to prevent wasted time and effort.

2. Connect the positive power lead directly to the vehicle

battery positive terminal. Connecting the Positive lead to

any other positive voltage source in the vehicle is not rec-

ommended.

3. Connect the ground lead directly to the battery negative

terminal.

4. The cable provided with the radio is sufficient to handle

the maximum radio current demand. If the cable must be

extended, be sure the additional wire is sufficient for the

current to be carried and length of the added lead.

TK-785

4. INSTALLATION PLANNING CONTROL STATIONS

4-1. Antenna system

Control station. The antenna system selection depends

on many factors and is beyond the scope of this manual.

Your KENWOOD dealer can help you select an antenna sys-

tem that will best serve your particular needs.

4-2. Radio location

Select a convenient location for your control station radio

which is as close as practical to the antenna cable entry

point. Secondly, use your system's power supply (which

supplies the voltage and current required for your system).

Make sure sufficient air can flow around the radio and power

supply to allow adequate cooling.

SERVICE

This radio is designed for easy servicing. Refer to the

schematic diagrams, printed circuit board views, and align-

ment procedures contained in this manual.

Note

When you modify your radio as described in system set-

up, take the following precaution.

The rating of pin 7 (SB) of the accessory connector cable

(KCT-19) on the rear of the radio is 13.2V (E), 13.6V (K,M).

Insert a 1A fuse if you use the SB pin for external equip-

ment.

Accessory connector

cable (KCT-19)

If you do not intend to use the 3.5-mm jack for the exter-

nal speaker, fit the supplied speaker-jack cap (B09-0235-05)

to stop dust and sand getting in.

GENERAL / OPERATING FEATURES

Speaker-jack cap

(B09-0235-05)

OPERATING FEATURES

1. Transceiver Controls and Indicators (Fig. 1)

1-1. The Basics

Features listed in this section are available for both

Trunking and Conventional modes. Mode specific features

can be found in their corresponding sections in this manual.

· Front panel

IO (Power) switch

Press to switch the transceiver ON (or OFF).

Transmit/Receive indicator

(Volume) keys

(Control) keys

Microphone jack

Insert the microphone plug into this connector.

6 s

key

A key

B key

C key

key

CALL key

1-2. Trunking Mode

· Key functions

The numbers correspond to the Figure 1.

Transmit indicator

Lights red while transmitting.

(Control) keys

Press these keys to select your desired call address

(voice calls) or status (status calls).

6 s

key

Press to end the current call.

A key (default setting : Status/Stack)

Press to activate its auxiliary function below.

B key (default setting : Redial)

Press to activate its auxiliary function below.

Fig. 1

TK-785

OPERATING FEATURES / REALIGNMENT

REALIGNMENT

1. Modes

User mode

Panel test mode

PC mode

Firmware program-

ming mode

Panel tuning mode

Data program-

ming mode

PC test mode

PC tuning mode

Mode

Function

User mode

For normal use.

Panel test mode

Used by the dealer to check the funda-

ment characteristics.

Panel tuning mode

Used by the dealer to tune the radio.

PC mode

Used for communication between the

radio and PC (IBM compatible).

Data programming

Used to read and write frequency data

mode

and other features to and from the radio.

PC test mode

Used to check the radio using the PC.

This feature is included in the FPU.

See panel tuning.

Firmware program-

Used when changing the main program

ming mode

of the flash memory.

2. How to Enter Each Mode

Mode

Operation

User mode

Power ON

Panel test mode

[B]+Power ON

PC mode

Received commands from PC

Panel tuning mode

[Panel test mode]+[A]

Firmware programming mode

[A]+Power ON

3. Panel Test Mode

Setting method refer to ADJUSTMENT.

4. Panel Tuning Mode

Setting method refer to ADJUSTMENT.

C key (Default setting : None)

Press to activate its auxiliary function below. Also press

to scroll left while viewing stack entries.

key (Default setting : None)

Press to activate its auxiliary function below. Also press

to scroll right while viewing stack entries.

CALL key

Press to call the displayed call address.

· Display

displays the strength of received signals, the output

power (high or low), status numbers, and received call

types.

appears when a control channel is found. It flashes

while the transceiver is searching for a control channel.

flashes when you activate call diversion.

appears while there is data in the stack. It flashes when

there is new data in the stack.

displays call addresses, the call dura-

tion timer, data messages, and the current operating status

of the transceiver.

1-3. Conventional Mode

· Key functions

The numbers correspond to the Figure 1.

Transmit/Receive indicator

Lights red while transmitting.

Lights green while receiving a signal.

(Control) keys

Press these keys to select your desired channel.

6 s

key

Press to return to Trunking mode.

A key

Press to turn Scan ON (or OFF).

B key

Press to add/remove channels to/from Scan.

CALL key

Press to turn the squelch OFF in order to monitor your

selected channel.

· Display (Refer to Figure 2)

displays the strength of received signals.

appears while you are monitoring a channel by press-

ing the CALL key.

appears while you are scanning.

displays channel numbers and the

current operating status of the transceiver.

Fig. 2

TK-785

REALIGNMENT

5. PC Mode

5-1. Preface

The TK-785 transceiver is programmed by using a per-

sonal computer, programming interface (KPG-46) and pro-

gramming software (KPG-62D).

The programming software can be used with an IBM PC

or compatible. Figure 1 shows the setup of an IBM PC for

programming.

5-2. Connection Procedure

1. Connect the TK-785 to the personal computer with the

interface cable.

2. When the Power switch on, user mode can be entered

immediately. When PC sends command the radio enter

PC mode, and "PROGRAM" is displayed on the LCD.

When data transmitting from transceiver, the red LED is

blinking.

When data receiving to transceiver, the green LED is

blinking.

Notes :

· The data stored in the personal computer must match

model type, when it is written into the flash memory.

· Change the TK-785 to PC mode, then attach the interface

cable.

5-3. KPG-46 Description

(PC programming interface cable : Option)

The KPG-46 is required to interface the TK-785 to the

computer. It has a circuit in its D-subconnector (25-pin) case

that converts the RS-232C logic level to the TTL level.

The KPG-46 connects the modular microphone jack of

the TK-785 to the computers RS-232C serial port.

5-4. Programming Software KPG-62D Description

The KPG-62D is the programming software for the trans-

ceiver supplied on two 3.5" floppy disks. This software runs

under MS-Windows 95/98 on an IBM-PC or compatible ma-

chine.

The data can be input to or read from the transceiver and

edited on the screen. The programmed or edited data can

be printed out. It is also possible to tune the transceiver.

We recommend that install the KPG-62D for example to

hard disk first then use it.

5-5. Programming With IBM PC

If data is transferred to the transceiver from an IBM PC

with the KPG-62D, the destination data (basic radio informa-

tion) for each set can be modified. Normally, it is not neces-

sary to modify the destination data because their values are

determined automatically when the frequency range (fre-

quency type) is set.

The values should be modified only if necessary.

Data can be programmed into the flash memory in RS-

232C format via the modular microphone jack.

KPG-46

IBM-PC

KPG-62D

TK-785

Fig. 1

6. Firmware Programming Mode

6-1. Preface

Flash memory is mounted on the TK-785. This allows the

TK-785 to be upgraded when new features are released in

the future. (For details on how to obtain the firmware, con-

tact Customer Service.)

6-2. Connection Procedure

Connect the TK-785 to the personal computer (IBM PC or

compatible) with the interface cable (KPG-46). (Connection

is the same as in the PC Mode.)

6-3. Programming

1. Start up the programming software (Fpro. exe).

2. Set the communications speed (normally, 57600 bps)

and communications port in the configuration item.

3. Set the firmware to be updated by File name item.

4. Turn the TK-785 Power ON with the [A] switch held

down. Hold the switch down until the display changes to

"PROG 57600". When "PROG 57600" appears, release

your finger from the switch.

5. Check the connection between the TK-785 and the per-

sonal computer, and make sure that the TK-785 is in the

Program mode.

6. Press write button in the window. A window opens on

the display to indicate progress of writing. When the TK-

785 starts to receive data, the

icon is blinking.

7. If writing ends successfully, the LED on the TK-785 lights

and the checksum is displayed.

8. If you want to continue programming other TK-785, re-

peat steps 4 to 7.

Tuning

cable