AR 10044831, Operating And Service Manual

Page: 16 / 52

Model 175A400
ii
3. THEORY OF OPERATION ............................................................................. 23
3.1 Introduction .......................................................................................................... 23
3.2 RF Amplifier Operation ....................................................................................... 23
3.2.1 A1 Pre-Amplifier Assembly (Schematic No. 10041189, 10041352, 10043496) . 23
3.2.1.1 A1 Pre-Amplifier Assembly (Schematic 1001189) ....................................... 23
3.2.1.2 A2 Switch Assembly (Schematic 10041352) ................................................ 23
3.2.1.3 A3 Output Amplifier Assembly (Schematic 10043496) ................................ 23
3.2.2 A2 Two-Way Splitter ........................................................................................... 23
3.2.3 A6–A7 100W 400MHz Module Assembly (Schematic 10039874) ..................... 24
3.2.4 A5 Two-Way Combiner ....................................................................................... 24
3.3 Power Supplies (PS1, PS2) .................................................................................. 24
3.4 Control System ..................................................................................................... 25
3.4.1 A12 Control/Fault Board (Schematic #10042218)............................................... 25
3.4.2 A14 Interface Board (Schematic #10020073) ...................................................... 25
4. MAINTENANCE ............................................................................................... 27
4.1 General Maintenance Information ........................................................................ 27
4.2 Disassembly Procedure ........................................................................................ 27
4.3 Troubleshooting ................................................................................................... 28
4.3.1 General - Reading Faults ...................................................................................... 28
4.3.2 The Unit Cannot Be Operated Remotely .............................................................. 29
4.3.3 Thermal Fault (Schematic Diagram Nos. 10044790, 10039874) ......................... 29
4.3.4 Interlock Fault (Schematic Diagram No. 10044790) ........................................... 29
4.3.5 Amplifier Faults (Schematic Diagram Nos. 10044790, 10039874) ..................... 30
4.3.6 Low or No Power Output (DC Tests) (Schematic Diagram No. 10044790) ........ 30
4.3.7 Low or No Power Output (RF Test) (Schematic Diagram Nos. 10044790
and 10039874) ...................................................................................................... 31
FIGURES
2-1 Model 175A400 Front Panel .................................................................................. 7
2-2 Model 175A400 Rear Panel ................................................................................... 8
2-3 Menu Map .............................................................................................................. 9
4-1 Typical Response at -20dBm Input ...................................................................... 31
4-2 Typical Response at 0dBm Input ......................................................................... 31
4-3 Typical A Module Response ................................................................................ 32
4-4 Typical A1 Pre-Amplifier Response .................................................................... 32
TABLES
2-1 RS-232 Port Settings ............................................................................................ 11
2-2 RS-232 (DCE) Port Pinout Diagram DB-9 Female.............................................. 11
2-3 Fiber-Optic Port Settings ...................................................................................... 12
2-4. Relationship between 175A400 Controls and Remote Communication .............. 14
2-5 States .................................................................................................................... 17
2-6 Faults .................................................................................................................... 18