Motorola EP350 User Manual

Table of Contents vii
8.4.3 Voltage Doubler and Charge Pump.................................................................................. 8-5
8.4.4 Loop Filter......................................................................................................................... 8-5
8.4.5 Dual VCO.......................................................................................................................... 8-5
8.5 Keypad........................................................................................................................................... 8-6
Chapter 9 VHF Troubleshooting Tables ............................................. 9-1
9.1 Troubleshooting Table for Receiver (VHF) ................................................................................... 9-1
9.2 Troubleshooting Table for Synthesizer (VHF) .............................................................................. 9-2
9.3 Troubleshooting Table for Transmitter (VHF) ............................................................................... 9-3
9.4 Troubleshooting Table for Board and IC Signals (VHF) ............................................................... 9-4
Chapter 10 VHF Schematic Diagrams, Overlays, and Parts Lists.... 10-1
10.1 Introduction .................................................................................................................................. 10-1
10.1.1 Notes For All Schematics and Circuit Boards................................................................. 10-1
10.1.2 Four Layer Circuit Board................................................................................................. 10-3
10.2 Speaker and Microphone Schematic........................................................................................... 10-3
10.2.1 Speaker and Microphone Parts List................................................................................ 10-3
10.3 Circuit Board/Schematic Diagram and Parts List (VHF: 136–174 MHz)...................................... 10-1
10.3.1 Parts List....................................................................................................................... 10-14
Chapter 11 403 – 447 MHz UHF1 Theory Of Operation ..................... 11-1
11.1 Introduction .................................................................................................................................. 11-1
11.2 UHF1 Receiver ............................................................................................................................ 11-1
11.2.1 Receiver Front End......................................................................................................... 11-2
11.2.2 Receiver Back End .........................................................................................................11-2
11.3 UHF1 Transmitter ........................................................................................................................ 11-3
11.3.1 Power Amplifier............................................................................................................... 11-3
11.3.2 Antenna Switch............................................................................................................... 11-3
11.3.3 Harmonic Filter ............................................................................................................... 11-3
11.3.4 Auto Power Control......................................................................................................... 11-4
11.4 UHF1 Frequency Generation Circuitry ........................................................................................ 11-4
11.4.1 Reference Oscillator (12.8 MHz VCTCXO) .................................................................... 11-4
11.4.2 PLL IC Prescaler and Comparator.................................................................................. 11-5
11.4.3 Voltage Doubler and Charge Pump................................................................................ 11-5
11.4.4 Loop Filter....................................................................................................................... 11-5
11.4.5 Dual VCO........................................................................................................................ 11-5
11.5 Keypad......................................................................................................................................... 11-6
Chapter 12 UHF1 Troubleshooting Tables......................................... 12-1
12.1 Troubleshooting Table for Receiver (UHF1) ............................................................................... 12-1
12.2 Troubleshooting Table for Synthesizer (UHF1) .......................................................................... 12-2
12.3 Troubleshooting Table for Transmitter (UHF1) ........................................................................... 12-3
12.4 Troubleshooting Table for Board and IC Signals (UHF1) ........................................................... 12-4
Chapter 13 UHF1 Schematic Diagrams, Overlays, and Parts Lists . 13-1
13.1 Introduction .................................................................................................................................. 13-1

Motorola EP350 Specifications

General

Channel Capacity	16 channels
IP Rating	IP54
Drop Resistance	1.2 meters
Frequency Range	VHF: 136-174 MHz, UHF: 403-470 MHz
Battery Life	Up to 11 hours
Power Supply	7.5 V (Nominal)
Waterproof	Splashproof
Dimensions	127.6 x 62 x 42 mm (with standard battery)