KENWOOD TK790 - Service Manual Immediate Download

B51-8438-10 (N) 1234

VHF FM TRANSCEIVER

TK-790/(B)

TK-790H(B)

SERVICE MANUAL

Cabinet (Upper)

(A01-2161-02)

Cabinet (Upper)

(A01-2163-01)

Panel assy

(A62-0606-13)

Panel assy

(A62-0607-13)

Cabinet (Lower)

(A01-2164-01)

Knob

(K29-4664-04) x 2

Cabinet (Lower)

(A01-2162-02)

Knob

(K29-4664-04) x 2

TK-790 or TK-790(B) with KCH-10

KCH-11

TK-790H(B)

This service manual applies to products with 30300001 or subsequent serial numbers. (KCH-10 and KCH-11 are applicable to

the productions June 2001 and after.)

In terms of the products with the serial numbers earier than 30300001, refer to the TK-790/(B)/H(B) service manual as per

part No. B51-8438-00 and the TK-790(B) service manual as per part No. B51-8456-00.

REVISED

TK-790/(B)/H(B)

CONTENTS / GENERAL

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

SYSTEM SET-UP ............................................................................................................. 4

OPERATING FEATURES ................................................................................................. 5

INSTALLATION .............................................................................................................. 16

DISASSEMBLY FOR REPAIR ......................................................................................... 22

CIRCUIT DESCRIPTION ................................................................................................. 26

SEMICONDUCTOR DATA ............................................................................................. 32

DESCRIPTION OF COMPONENTS ............................................................................... 36

PARTS LIST .................................................................................................................... 39

EXPLODED VIEW .......................................................................................................... 57

PACKING ........................................................................................................................ 61

ADJUSTMENT ............................................................................................................... 65

TERMINAL FUNCTION ................................................................................................. 74

WIRING .......................................................................................................................... 77

PC BOARD VIEWS / CIRCUIT DIAGRAMS

DISPLAY UNIT (X54-3190-20) : KCH-10 .................................................................. 79

DISPLAY UNIT (X54-3200-20) : KCH-11 .................................................................. 81

CONTROL UNIT (X57-5610-XX) (B/3) ..................................................................... 87

FINAL UNIT (X57-5610-XX) (C/3) : TK-790/(B) ....................................................... 97

TX-RX UNIT (X57-5610-XX) (A/3) ......................................................................... 101

FINAL UNIT (X45-3560-10) : TK-790H(B) .............................................................. 113

BLOCK DIAGRAM ........................................................................................................ 117

SPECIFICATIONS ......................................................................................................... 119

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 this publica-

tion date. Changes which may occur after publication are

covered by either Service Bulletins or Manual Revisions,

which 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, and 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 required 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 secure and

any open connectors are properly terminated.

· SHUT OFF this equipment when near electrical blasting

caps or while in an explosive atmosphere.

· All equipment should be properly grounded before

power-up for safe operation.

· This equipment should be serviced by only qualified tech-

nicians.

TK-790/(B)/H(B)

PRE-INSTALLATION CONSIDERATIONS

1. UNPACKING

Unpack 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 ra-

dio installation (mobile or base) be obtained by the equip-

ment owner. The licensee is responsible for ensuring trans-

mitter power, frequency, and deviation are within the limits

permitted by the station license.

Transmitter adjustments may be performed only by a li-

censed technician holding an FCC first, second or general

class commercial radiotelephone operator's license. There

is no license required to install or operate the radio.

3. PRE-INSTALLATION CHECKOUT

3-1. Introduction

Each radio is adjusted and tested before shipment. How-

ever, it is recommended that receiver and transmitter opera-

tion be checked for proper operation before installation.

3-2. 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.

4. PLANNING THE INSTALLATION

4-1. 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.

4-2. 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.

4-3. 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.

4-4. 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. 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.

5. INSTALLATION PLANNING CONTROL STATIONS

5-1. 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.

5-2. 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.

GENERAL

TK-790/(B)/H(B)

Before Reading About System Set-up

The TK-790(B)/H(B) is a transceiver main unit (without a

panel or speaker) that you complete by adding options.

The options are classified into three types according to

operation and function.

1. Install the front panel kit (controller) directly on a radio to

operate it. (Form : Radio + KCH-10/11)

2. Remotely control one radio with one controller. (Form

: Radio + KRK-5 + KCH-10/11 + KCT-22M/M2/M3)

SYSTEM SET-UP

*Service manual parts No. list

Model

Parts No.

KRK-5/6DH

B51-8445-00

KRK-7DB/8DBH

B51-8452-00

Merchandise received

License and frequency allocated by FCC

Choose the type of transceiver

TK-790/(B), TK-790H(B) (Radio 1)

TK-790(B) or TK-790H(B) is complete by combining

options with only the transceiver body (without panel)

Are you using the remote kit?

KCH-10 (Basic model)

Front panel kit

KCH-11 (Full featured

model) Front panel kit

Supplied accessory knob

Are you using one radio with two controllers?

Are you using one radio

with one controller?

Are you using two radios with one controller?

Are you using two radios with two controllers?

TK-790 : Contain (KCH-10)

Are you using the printed keytops?

KRK-5

Single control head kit

KRK-7DB

Dual band remote kit

KRK-6DH

Dual control head kit

KCH-10

KCH-11

KCH-10

KCH-11

KCH-10

KCH-11

KCT-22M/M2/M3

Control cable

YES

*See Remote

kit service

manual

See

page 16

See page 16

YES

KRK-8DBH

Dual band dual control head kit

KCH-10

KCH-11

YES

Frequency range

148~174MHz

YES

*See Remote kit

service manual

Are you using the voice scrambler?

Transceiver programming (option)

Are you using the external speaker?

KCT-23 (DC cable)

Are you using the ignition sense cable?

Delivery

Modified of control unit

YES

KES-4 (EXT. SP)

YES

KCT-18

YES

See page 18

See page 17

See page 13

A personal computer (IBM PC or compatible), programming interface (KPG-43),

and programming software (KPG-44D) are required for programming.

(The frequency and signalling data are programmed for the transceiver.)

See Installation manual

KCT-23 M,M3 : TK-790/(B), KCT-23 M2,M4 : TK-790H(B)

RF power

45W

110W

TK-790/(B) F1

136~156MHz

45W

TK-790(B) F2

TK-790H(B) F1

Type

3. Remotely control one radio with two controllers. (Form

: Radio + KRK-6DH + KCH-10/11 (two) + KCT-22M/M2/

M3 (two))

4. Remotely control two radios with one controller. (Form

: Radios (two) + KRK-7DB + KCH-10/11 + KCT-22M/M2/

M3)

5. Remotely control two radios with two controllers. (Form

: Radio (two) + KRK-8DBH + KCH-10/11 (two) + KCT-

22M/M2/M3 (two))

TK-790/(B)/H(B)

1. Controls and Functions

1-1. Basic Function Panel

(1) POWER Switch

Press to turn the power ON and OFF.

(2) TX/BUSY Indicator

The TX Indicator (Red LED) shows that you are transmit-

ting.

The BUSY Indicator (Green LED) shows that the channel

is in use.

(3) Microphone Connector

(4) Volume Knob

To increase the volume level, turn clockwise (CW).

To decrease the volume level, turn counterclockwise

(CCW).

(5) UP/DOWN Knob

The function of this Knob can be programmed by the

FPU.

Function

Description

Note

Channel

Channel selector.

Default

UP/DOWN

To increase the channel, turn CW.

setting.

To decrease the channel, turn CCW.

Group

Group selector.

UP/DOWN

To increase the group, turn CW.

To decrease the group, turn CCW.

(6) GR UP Key, (7) GR DW Key, (8) MON Key, (9) SCN Key,

(10)~(18) PF1-9 Key

The function of these Keys can be programmed by the

FPU.

Function

Description

Note

[ ] : Key top name

No function.

Default setting

Function

of PF1~9.

Monitor

If [MON] is pressed once while

Default setting

[MON]

the RADIO is waiting for reception,

of MON. (Full

all signalling* squelch is canceled.

function panel)

If [MON] is held down for 2 seconds,

all singalling;

noise squelch is canceled and the

QT/DQT &

audio is unmuted.

2 TONE/DTMF

Scan

Start and stop the scanning

Default setting

[SCN]

sequence.

of SCN. (Full

function panel)

Public

The RADIO works as a PUBLIC

Address [PA]

ADDRESS amplifier.

Horn Alert

When the RADIO receives a

[HA]

the optional signalling calls that

are assigned to the channel, the

HA relay turns on.

Talk Around

Use this function to communicate

[TA]

with other operators directry,

without using a repeater.

Intercom

Use this function to communicate

Dual HEAD

[IC]

between the HEAD1 and HEAD2

configuration

operator without transmitting.

only.

OPERATING FEATURES

GRP

VOL

POWER

TX BUSY

(1)

(2) (3)

(4)

(5)

(10)

(11)

(12)

(13)

(14)

(19)

(7)

(6)

(20)

(29)

(32)

(30)

(31)

(21) (22)(23)

(24)

(25)

(26)

(27)

(28)

1-2. Full Function Panel

GRP

POWER

VOL

BUSY

SCAN

OPT

OST

MON

CALL

MON

SCN

(1)

(2) (3)

(4)

(5)

(10)

(11)

(12)

(13)

(14)

(6) (7)

(19)

(9) (8)(17) (15) (16)

(18)

SCAN

OPT

OST

MON

CALL

(29) (31)

(20)

(21)

(22)

(23)

(24) (25)

(26)

(27) (28)(30)

(32)