Specifications

4-6 888-2500-001 5/2/2013
WARNING: Disconnect primary power prior to servicing.
DAX-1/DAX-3
Section 4 Theory of Operation
4.4 Power Supply System
The power supply system provides all DC power for the transmitter. The DC power for
the RF power amplifiers (B+) is provided in two controller-selected DC voltage levels:
200Vdc, and 300Vdc. The RF power amplifiers will only be powered from one of these
selectable voltage levels at a time. The transmitter’s control system will select which
DC power level is used to power the RF amplifiers. Depending on the transmitter output
power setting, the control system will adjust the 200Vdc supply between 80Vdc and
200Vdc in order to optimize the transmitter’s RF performance at lower power levels.
The power supply system also provides the following fixed low voltage supplies:
+48Vdc, +12Vdc and -12Vdc.
Figure 4-4 Power Supply System Block Diagram
4.4.1 RF PA Power Supply (B+)
The RF PA power supply (also referred to as the B+ supply) provides power to the
power amplifier circuitry. The operation of the B+ supply is outlined below.