UBS Axcera 425A Table of Contents

500-Watt VHF Transmitter Table of Contents

TABLE OF CONTENTS

CHAPTER 1 INTRODUCTION

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 Broadcast 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

2.2.2 600-Watt Amplifier Tray ...............................................................2-6

2.3 Input and Remote Connections...............................................................2-7

2.4 AC Input............................................................................................2-10

CHAPTER 3 CIRCUIT DESCRIPTIONS

3.1 High-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................................................................3-17

3.1.9 Visual/Aural Metering Board.............................................................3-22

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

3.2 600-Watt High-Band VHF 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 High-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

5.5 Linearity Corrector Adjustment...............................................................5-3

5.6 Phase and Gain Adjustment of the VHF Amplifier Trays .............................5-4

425A, Rev. 0 i

500-Watt VHF Transmitter Table of Contents

TABLE OF CONTENTS (continued)

5.7 Calibration of the Forward Output Power Level of the Transmitter...............5-5

5.8 Calibration of the Reflected Output Level of the Transmitter.......................5-5

5.9 2-Way Combiner Assembly ....................................................................5-6

5.10 Bandpass Filter Assemblies ..................................................................5-6

5.11 600-Watt High-Band VHF Amplifier Tray ................................................5-6

5.11.1 AGC Control Board.....................................................................5-6

5.11.2 Phase Shifter Board....................................................................5-7

5.11.3 VHF Filter/Amplifier Board...........................................................5-7

5.11.4 High-Band VHF Amplifier Board ...................................................5-7

5.11.5 Overdrive Protection Board .........................................................5-7

5.11.6 VHF High-Band Amplifier Board ...................................................5-7

5.11.7 4-Way Splitter Board..................................................................5-8

5.11.8 High-Band Amplifier Board..........................................................5-8

5.11.9 4-Way Combiner Board...............................................................5-8

5.11. 10 C a lib rat ion of the V isua l P lus Au ra l Ou tp ut

Power and VSWR Cutback.........................................................5-8

5.12 Board Level Alignment Procedures ........................................................5-9

5.12.1 (Optional) 4.5-MHz Composite Input Kit .......................................5-9

5.12.2 Delay Equalizer Board...............................................................5-10

5.12.3 Composite 4.5-MHz Filter Board.................................................5-10

5.12.4 (Optional) 4.5-MHz Bandpass Filter Board...................................5-10

5.12.5 IF Carrier Oven Oscillator Board.................................................5-11

5.12.6 Sync Tip Clamp/Modulator Board...............................................5-11

5.12.7 Aural IF Synthesizer Board, 4.5 MHz ..........................................5-13

5.12.8 ALC Board (Part 1 of 2).............................................................5-14

5.12.9 IF Phase Corrector Board ..........................................................5-15

5.12.10 ALC Board, NTSC (Part 2 of 2).................................................5-15

5.12.11 Channel Oscillator Board, Dual Oven ........................................5-16

5.12.12 x4 Multiplier Board .................................................................5-16

5.12.13 VHF Filter/Mixer Board............................................................5-16

5.12.14 High-Band VHF Filter/Amplifier Board .......................................5-17

APPENDICES
APPENDIX A SYSTEM SPECIFICATIONS
APPENDIX B SAMPLE LOG REPORT SHEET
APPENDIX C ASSEMBLY DRAWINGS
APPENDIX D SUBASSEMBLY DRAWINGS

425A, Rev. 0 ii