Specifications

5/2/2013 888-2500-001 4-1
WARNING: Disconnect primary power prior to servicing.
DAX-1/DAX-3
Section 4
Theory of
Operation
4
4.1 Introduction
This section provides block diagram level theory to assist the technician in
understanding and troubleshooting the transmitter.
System level, subsystems, and assemblies all fall under the following headings:
• Control
• RF
• Power Supply
4.2 Control
4.2.1 Exciter/Controller
The Exciter/Controller board performs the following functions:
4.2.1.1 DSP
The DSP for the Exciter performs the supervisory, and adaptive correction algorithms.
Upon reset or power up of a factory configured board, the DSP boots from memory,
verifies configuration, configures the FPGA, initializes configuration registers in the
FPGA.
4.2.1.2 Synthesizer
The synthesizer in the exciter is uses a Numerically Controlled Oscillator (NCO) to
develop the carrier frequency in the absence of an external carrier input. Either an
internal 10MHz precision oscillator or an external 10MHz input can be used as the
reference and the internal/external clock reference is software selectable.