Table of Contents
3.7.4.11 Transmitter VCOs...................................................................................................3-61
3.7.4.12 Receiver VCOs.......................................................................................................3-62
3.8
Controller Section.........................................................................................................................3-62
3.8.1
Daughtercard Module ......................................................................................................3-64
3.8.2
3.8.3
Encryption Voltages ........................................................................................................3-66
3.8.4
Reset Circuits ..................................................................................................................3-67
3.8.5
3.8.5.1
3.8.5.2
3.8.5.3
3.8.6
3.8.7
RS-232 USB Bus.............................................................................................................3-69
3.8.8
3.8.9
3.8.10 Receive Audio .................................................................................................................3-72
3.8.11 Transmit Audio ................................................................................................................3-74
3.8.12 Flash Programming .........................................................................................................3-75
4.1
Introduction.....................................................................................................................................4-1
4.2
Handling Precautions .....................................................................................................................4-1
4.2.1
4.2.2
Rigid Circuit Boards...........................................................................................................4-2
4.2.3
Heat-Related Precautions .................................................................................................4-2
4.2.4
Daughtercard Module ........................................................................................................4-2
4.2.4.1
4.2.4.2
4.3
4.4
Power-Up Self-Check Errors ..........................................................................................................4-3
4.5
Operational Error Codes ................................................................................................................4-5
4.6
VHF (136-174 MHz) Band Main Board Troubleshooting...............................................................4-5
4.6.1
4.6.2
VCO Hybrid Assembly.......................................................................................................4-6
4.6.3
Out-of-Lock Condition .......................................................................................................4-7
4.6.4
FGU Troubleshooting Aids ................................................................................................4-7
4.6.5
4.6.6
No or Low Modulation .....................................................................................................4-11
4.6.7
4.7
4.7.1
4.7.2
FGU Troubleshooting Aids ..............................................................................................4-13
4.7.3
Out-of-Lock Condition .....................................................................................................4-16
4.7.4
4.7.5
No or Low Modulation .....................................................................................................4-16
4.7.6
4.8
UHF Range 2 (450-520 MHz) Band Main Board Troubleshooting ..............................................4-17
4.8.1
Display Flashes "FAIL 001" .............................................................................................4-17
4.8.2
FGU Troubleshooting Aids ..............................................................................................4-19
6881096C74-B
Power Turn-On.......................................................................................................3-68
Power Turn-Off.......................................................................................................3-68
SRAM .......................................................................................................................4-2
Testing......................................................................................................................4-2
ix
May 25, 2005