Model 500A250D
ii
2.4.6.16
SBB (Piggyback) Firmware Revision ............................................................ 21
2.4.6.17
System Serial Number ................................................................................... 22
2.4.6.18
AC Power-On Defaults .................................................................................. 22
2.4.7
Interlocks .............................................................................................................. 23
2.4.7.1
Inhibit Interlock ............................................................................................. 23
3.
THEORY OF OPERATION ............................................................................. 25
3.1
Introduction .......................................................................................................... 25
3.2
RF Amplifier Operation ....................................................................................... 25
3.2.1
A1 Pre-Amplifier Assembly (Schematic No. 10045472, 10041352, 10045475) . 25
3.2.1.1
A1 Pre-Amplifier Assembly (Schematic 10045472) ..................................... 25
3.2.1.2
A2 Switch Assembly (Schematic 10041352) ................................................ 25
3.2.1.3
A3 Output Amplifier Assembly (Schematic 10045475) ................................ 25
3.2.2
A2 100W 250MHz Driver Module Assembly (Schematic 10039874) ................ 26
3.2.3
A3 Two-Way Splitter ........................................................................................... 26
3.2.4
A4, A5 Three-Way Splitter .................................................................................. 26
3.2.5
A6, A8, A9, A10, A12, A13 100W 250MHz Module Assembly (Schematic
10039874) ........................................................................................................... 26
3.2.6
A24, A25, A26 Two-Way Combiners .................................................................. 27
3.2.7
A14 Three-Way Combiner ................................................................................... 27
3.2.8
A15 Bi-Directional Coupler ................................................................................. 27
3.2.9
A16 Detector (Schematic 10045651) ................................................................... 27
3.3
Power Supplies (PS1, PS2, Ps3) ........................................................................... 27
3.4
Control System ..................................................................................................... 28
3.4.1
A18 Control/Fault Board (Schematic 10042218)................................................. 28
3.4.2
A20 Interface Board (Schematic 10020073) ........................................................ 28
3.4.3
A17 ALC .............................................................................................................. 28
3.5
Sample Ports ......................................................................................................... 28
4.
MAINTENANCE ............................................................................................... 29
4.1
General Maintenance Information ........................................................................ 29
4.2
Disassembly Procedure ........................................................................................ 29
4.3
Troubleshooting ................................................................................................... 30
4.3.1
General - Reading Faults ...................................................................................... 30
4.3.2
The Unit Cannot Be Operated Remotely .............................................................. 31
4.3.3
Thermal Fault (Schematic Diagrams 10045748, 10039874) ................................ 31
4.3.4
Interlock Fault (Schematic Diagram 10044770) .................................................. 31
4.3.5
Amplifier Faults (Schematic Diagrams 10045748, 10039874) ............................ 32
4.3.6
Low or No Power Output (DC Tests) (Schematic Diagram 10045748) .............. 32
4.3.7
Low or No Power Output (RF Test) (Schematic Diagrams 10045748
and 10039874) ...................................................................................................... 33
FIGURES
2-1
Model 500A250D Front Panel ............................................................................... 7
2-2
Model 500A250D Rear Panel ................................................................................ 8
2-3
Menu Map .............................................................................................................. 9
4-1
Typical Response at -20dBm Input ...................................................................... 33
4-2
Typical Response at 0dBm Input ......................................................................... 33
4-3
Typical A Module Response ................................................................................ 34
4-4
Typical A1 Pre-Amplifier Response .................................................................... 34