System Description

500-Watt VHF Low Band Transmitter Table of Contents
325A, Rev. 0 i August 1, 2002
TABLE OF CONTENTS
CHAPTER 1 INTRODUCTION
SECTION PAGE
1.1 Manual Overview ..................................................................................1-1
1.2 Assembly Designation Procedure ............................................................1-1
1.3 Safety .................................................................................................1-1
1.4 Maintenance.........................................................................................1-2
1.5 Material Return Procedure......................................................................1-2
1.6 Warranty for Axcera Products – Limited One-Year Warranty ......................1-3
CHAPTER 2 SYSTEM DESCRIPTION
2.1 System Overview..................................................................................2-1
2.2 Control and Status................................................................................2-2
2.2.1 VHF Exciter Tray..........................................................................2-3
2.2.2 VHF Amplifier Tray .......................................................................2-6
2.3 Input and Remote Connections...............................................................2-7
2.4 AC Input ............................................................................................2-10
CHAPTER 3 CIRCUIT DESCRIPTIONS
3.1 Low-Band VHF Exciter ...........................................................................3-1
3.1.1 Aural IF Synthesizer Board, 4.5 MHz ..............................................3-1
3.1.2 Sync Tip Clamp/Modulator Board...................................................3-2
3.1.3 Delay Equalizer Board ..................................................................3-5
3.1.4 IF Carrier Oven Oscillator Board ....................................................3-6
3.1.5 ALC Board, NTSC.........................................................................3-7
3.1.6 IF Phase Corrector Board............................................................3-13
3.1.7 VHF Mixer/Amplifier Enclosure Assembly ......................................3-15
3.1.8 Transmitter Control Board...........................................................3-16
3.1.9 Visual/Aural Metering Board........................................................3-21
3.1.10 Channel Oscillator Assembly, Dual Oven.....................................3-23
3.1.11 EEPROM FSK Identifier Board ....................................................3-23
3.1.12 IF Attenuator Board..................................................................3-24
3.2 VHF Low-Band Amplifier Trays..............................................................3-24
3.3 Bandpass Filter Assembly ....................................................................3-28
CHAPTER 4 INSTALLATION AND SETUP PROCEDURES
4.1 Site Considerations ...............................................................................4-1
4.2 Unpacking the Cabinets and Trays ..........................................................4-4
4.3 Installing the Cabinets and Trays............................................................4-5
4.4 Setup and Operation .............................................................................4-6
CHAPTER 5 DETAILED ALIGNMENT PROCEDURES
5.1 Low-Band VHF Exciter Tray with Baseband Video and Audio Inputs ............5-1
5.2 VHF Exciter Tray with 4.5-MHz Composite Input Kit ..................................5-1
5.3 VHF Exciter Tray with Either Baseband or 4.5-MHz Composite Input ...........5-2
5.4 IF Phase Corrector Adjustment...............................................................5-3