User's Manual

Theory of Operation

This chapter is organized to provide descriptions of the circuitry

contained on the schematics shown in chapter 8. A block diagram

overview is provided followed by more detailed descriptions of the

circuitry contained in the schematics chapter.

 Block Diagram Overview . . . . . . . . . . . . . . . . 85

 Output Attenuator . . . . . . . . . . . . . . . . . . . 86

 Output Amplifier . . . . . . . . . . . . . . . . . . . . 87

 AM Modulation . . . . . . . . . . . . . . . . . . . . . 89

 Pre-attenuator . . . . . . . . . . . . . . . . . . . . . . 90

 Square Wave and Sync . . . . . . . . . . . . . . . . . 90

 Filters . . . . . . . . . . . . . . . . . . . . . . . . . . 92

 Waveform DAC/Amplitude Leveling/Waveform RAM . . 93

 Direct Digital Synthesis (DDS ASIC) . . . . . . . . . 95

 System DACs . . . . . . . . . . . . . . . . . . . . . . 96

 Floating Logic . . . . . . . . . . . . . . . . . . . . . . 97

 Earth-Referenced Logic . . . . . . . . . . . . . . . . . 98

 Power Supplies . . . . . . . . . . . . . . . . . . . . . 98

 Display and Keyboard . . . . . . . . . . . . . . . . . . 100

The self-test procedures are described in chapter 6.