Filter
Top Products
ii
Circuit Description
Introduction 34
Signal Amplifier 34
Current Amplifier 34
Notch Filters 34
Bandpass Filter 34
Reference Oscillator 35
PSD, LP Filters and DC Amplifier 35
Analog Output 36
A/D's 36
D/A's 36
Expand 36
Front Panel 36
Microprocessor Control 36
RS232 Interface 37
GPIB Interface 37
Power Supplies 37
Internal Oscillator 37
Calibration and Repair
Introduction 38
Multiplier Adjustments 38
Amplifier and Filter Adjustments 38
CMRR Adjustment 38
Line Notch Filter Adjustment 39
2xLine Notch Filter Adjustment 39
Repairing Damaged Front-End 39
Appendix A: Noise Sources and Cures
Johnson Noise 40
'1/f' Noise 40
Noise Spectrum 40
Capacitive Coupling 41
Inductive Coupling 41
Ground Loops 42
Microphonics 42
Thermocouple Effect 42
Appendix B: RS232
Simplest Case Using the RS232 43
Using Control Lines 43
Baud Rates 43
Stop Bits 44
Parity 44
Voltage Levels 44
'Eavesdropping' 44
Appendix C: GPIB
Introduction to the GPIB 45
Bus Description 45
Appendix D: Program Examples
Program Description 46
IBM PC, Microsoft Basic, via RS232 46
IBM PC, Microsoft Fortran, via RS232 47
IBM PC, Microsoft C, via RS232 49
IBM PC, Microsoft Basic, via GPIB 51
HP-85, HP Basic, via HPIB 53
Documentation
Parts List, Oscillator Board 55
Parts List, Main Board 56
Parts List, Front Panel Board 70
Parts List, Quad Board 73
Parts List, Miscellaneous 77
Schematic Diagrams 79