TABLE OF CONTENTS

TABLE OF CONTENTS (CONT’D)

3.10 SYNTHESIZER CIRCUIT DESCRIPTION

(800/900 MHz MODELS). . . . . . . . . . . . . . .3-22

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22

Voltage-Controlled Oscillator . . . . . . . . . . . . . 3-22

VCO and TCXO Modulation . . . . . . . . . . . . . . 3-24

Active Filter (Q800) . . . . . . . . . . . . . . . . . . . . . 3-25

Buffer Amplifier (Q801), Tx/Tx Switch

(CR801/CR802) . . . . . . . . . . . . . . . . . . . . . . 3-25

Synthesizer Integrated Circuit (U804) . . . . . . . 3-26

Lock Detect . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-27

Charge Pump . . . . . . . . . . . . . . . . . . . . . . . . . . 3-27

Shift Register (U800, U801) and Digital

Potentiometer (U802) Programming . . . . . . 3-27

3.11 RECEIVER CIRCUIT DESCRIPTION

(800/900 MHz MODELS). . . . . . . . . . . . . . .3-27

Front End Filter . . . . . . . . . . . . . . . . . . . . . . . . 3-27

RF Amplifier (Q201) . . . . . . . . . . . . . . . . . . . . 3-27

First Mixer (Q202), Crystal Filter (Z204) . . . . 3-28

Second Mixer/Detector (U201) . . . . . . . . . . . . 3-28

3.12 TRANSMITTER CIRCUIT DESCRIPTION

(800/900 MHz MODELS). . . . . . . . . . . . . . .3-29

Predriver (Q506), Driver (Q507) . . . . . . . . . . . 3-29

Power Amplifier Module (U600), Final (Q651) 3-30

Antenna Switch . . . . . . . . . . . . . . . . . . . . . . . . 3-30

Directional Coupler, Low-Pass Filter. . . . . . . . 3-30

Power Control (U500A/B, Q500-Q503) . . . . .3-31

4 SERVICING

4.1 GENERAL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-1 Periodic Checks . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 Schematic Diagrams and Component Layouts. . 4-1 Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . 4-1 Configuring Transceiver for Testing . . . . . . . . . 4-1

4.2 SURFACE MOUNTED DEVICES (SMDs) . .4-1 Servicing Techniques . . . . . . . . . . . . . . . . . . . . . 4-1 Identifying SMD Resistors . . . . . . . . . . . . . . . . . 4-1 SMD Capacitor Identification . . . . . . . . . . . . . . 4-2 SMD Inductor Identification . . . . . . . . . . . . . . . 4-3 Transistor/Diode Identification . . . . . . . . . . . . . 4-3

4.3 SYNTHESIZER TROUBLESHOOTING . . . .4-3 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3 Reference Oscillator (U806). . . . . . . . . . . . . . . . 4-4 VCO Module . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4 Synthesizer IC (U804) . . . . . . . . . . . . . . . . . . . . 4-4 Determining Synthesizer Counter Divide

Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-54.4 RECEIVER SERVICING. . . . . . . . . . . . . . . . . .4-5

4.5 TRANSMITTER SERVICING . . . . . . . . . . . . .4-5

4.6 AUDIO/LOGIC BOARD SERVICING. . . . . . .4-5

Digital Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

Analog Circuits. . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

5 PARTS LIST

Front Panel Assembly and Mechanical Parts . . . 5-1

UHF RF and PA Boards . . . . . . . . . . . . . . . . . . . 5-3

800/900 MHz RF and PA Boards . . . . . . . . . . . 5-18

Audio/Logic Board . . . . . . . . . . . . . . . . . . . . . . 5-25

9800-Series Radio Mounting Kit . . . . . . . . . . . 5-30

9800-Series Remote Mounting Kit . . . . . . . . . . 5-30

DC Power Cable and Hardware Kit . . . . . . . . . 5-30

Accessory Wire Kit . . . . . . . . . . . . . . . . . . . . . . 5-30

Amplified Dynamic Microphone . . . . . . . . . . . 5-30

15 Watt, 4.7-Ohm Speaker (Black) . . . . . . . . . . 5-30

Exploded Views

Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . 5-31

Front and Top . . . . . . . . . . . . . . . . . . . . . . . . 5-32

Bottom. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-32

Remote Control Unit. . . . . . . . . . . . . . . . . . . 5-33

Remote Transceiver . . . . . . . . . . . . . . . . . . . 5-33

6SCHEMATIC DIAGRAMS AND COMPONENT LAYOUTS

Amplified Dynamic Microphone . . . . . . . . . . . . 6-2

Transceiver Top Photo . . . . . . . . . . . . . . . . . . . . 6-3

Transceiver Bottom Photo. . . . . . . . . . . . . . . . . . 6-3

Interconnect Schematic. . . . . . . . . . . . . . . . . . . 6-4

Interface Board Layout. . . . . . . . . . . . . . . . . . . 6-4

Display Board

Top View. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5 Bottom View . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5

RPI (P.N. 023-9800-000)

Board Layout. . . . . . . . . . . . . . . . . . . . . . . . . . 6-6

Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6

Programming Cable (P.N. 597-2002-200) . . .6-6

Component Locator Guides

UHF RF Board . . . . . . . . . . . . . . . . . . . . . . . . 6-7

800/900 MHz RF Board . . . . . . . . . . . . . . . . 6-10

Audio/Logic Board . . . . . . . . . . . . . . . . . . . . 6-12

430-470 MHz RF

RF Board Schematic (Revised Board . . . . . . 6-15

PA Board Schematic (25W) . . . . . . . . . . . . . 6-15

RF Board Layout (Revised Board) . . . . . . . . 6-16

VCO Board Layout . . . . . . . . . . . . . . . . . . . . 6-17

PA Board Layout (25W) . . . . . . . . . . . . . . . . 6-17

PA Board Schematic (40W) . . . . . . . . . . . . . 6-18

PA Board Layout (40W) . . . . . . . . . . . . . . . . 6-19

RF Board Schematic (Unrevised Board) . . . 6-20

RF Board Layout (Unrevised Board) . . . . . . 6-21

 

February 2001

iii

Part No. 001-9800-001