Codan Radio Communications VT-3H040-S-HSO User Manual
iv
Transmitter Main Board Instruction Manual IM20-MT3TXMN
2.4
Version 2.3 Audio Processor .................................................................................2-15
2.4.1
Introduction......................................................................................................2-15
2.4.2
Version 2.3 FM Audio Processor Block Diagram ...........................................2-17
2.4.3
Factory Configuration......................................................................................2-18
2.4.4
Turn-on Time...................................................................................................2-19
2.4.5
Low Frequency Modulation.............................................................................2-19
2.4.6
Audio Processor Signals..................................................................................2-20
2.4.6.1
FM Audio Processor Outputs......................................................................2-20
2.4.6.2
Audio Processor Modulation Outputs .........................................................2-20
2.4.6.3
Audio Processor Microphone Input.............................................................2-21
2.4.6.4
Audio Processor Balanced Input..................................................................2-21
2.4.6.5
Audio Processor Auxiliary Input .................................................................2-21
2.4.6.6
Audio Processor Subtone Inputs .................................................................2-22
2.4.6.7
Direct Modulation Input ..............................................................................2-22
2.4.6.8
Low Frequency Modulation.........................................................................2-22
2.4.7
Audio Processor Signal Paths (Version 2.3)....................................................2-23
3
TRANSMITTER ALIGNMENT .....................................................................................3-1
3.1
General...................................................................................................................3-1
3.2
Repair Note............................................................................................................3-1
3.3
Printed Circuit Board Numbering Convention .......................................................3-1
3.4
Recommended Test Equipment List.......................................................................3-2
3.5
Standard Factory Settings and Jumper Configuration............................................3-2
3.5.1
MT-3 Transmitter Main Board Factory Configuration.....................................3-2
3.6
MT-3 Transmitter Main Board Configuration........................................................3-4
3.6.1
General.............................................................................................................3-4
3.6.2
MT-3 Transmitter Main Board Test Points......................................................3-4
3.7
Module Installation and Removal...........................................................................3-5
3.8
Audio Processor Alignment ...................................................................................3-6
3.8.1
Multiple Channel Transmitters.........................................................................3-7
3.8.2
Audio Processor Version Identification and Adjustment Locations..................3-7
3.8.3
Audio Processor Alignment Procedures...........................................................3-9
3.8.3.1
Transmitters with Pre-Emphasis and CTCSS Subtone ................................3-9
3.8.3.2
Transmitters with Flat Audio and CTCSS subtone ......................................3-13
4
TROUBLESHOOTING ..................................................................................................4-1
4.1
Balanced Input Test................................................................................................4-1
4.2
Frequency Response Test ......................................................................................4-1
4.3
Subtone Input Test.................................................................................................4-1
5
TEMPERATURE COMPENSATION ............................................................................5-1
6
TRANSMITTER INTERCONNECT PIN DEFINITIONS ............................................6-1
7
AUDIO PROCESSOR JUMPER CONFIGURATIONS...............................................7-1
7.1
Version 1.8 Audio Processor Jumper Configuration..............................................7-1
7.2
Version 2.3 Audio Processor Jumper and Select Value Tables ..............................7-3