Nautel VX150, Operation & Maintenance Manual

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VX150 TO VX2 OPERATIONS & MAINTENANCE MANUAL DESCRIPTION
VERSION 1.0 2022-12-08 PAGE 2.1.1
SECTION 2.1: DESCRIPTION
This section provides a high-level description of the transmitter’s key sections. The transmitter circuitry
is subdivided into three basic stages:
 Ac-Dc Power Stage
 Control/Excitation/Monitor Stage - see page 2.1.2
 RF Stage - see page 2.1.4
Refer to Figure Figure 2.1.1 through Figure Figure 2.1.3 , at the end of this section, for high level block
diagrams of the VX150 to VX2. For detailed electrical schematics of the transmitter and its sub-
assemblies, refer to Section 4 of the VX150 to VX2 Troubleshooting Manual.
Ac-Dc Power Stage
The ac-dc power stage provides power to operate the +12 V Power Supply, which generates the +12 dc
voltage that is used throughout the transmitter. This supplies the voltage to operate cooling fans, IPA
(intermediate power amplifier), and power all PWBs. The ac-dc power stage also contains a PA (power
amplifier) Power Supply that provides positive dc voltage (PA volts) to the PA PWB(s) for the RF power
amplifier(s). The PA Power Supply, and its output voltage range, varies with the transmitter model. For
VX150 to VX600 transmitters, the output voltage range is b18 and 53 V dc. For VX1 to VX2
transmitters, the output voltage range is b23 and 65 V dc.
For normal operation:
 VX150 to VX600 transmitters accept a single-phase, 90 - 265 V ac (120/220 V ac nominal)
input.
 VX1 to VX2 transmitters accept a single-phase, 185 - 265 V ac (220 V ac nominal) input.
NOTE
: VX1 to VX2 transmitters can operate from a 90 - 185 V ac input, but at reduced output power.
The ac-dc power stage consists of Power Supply Interface PWB (A4), Low Voltage Power Supply (LVPS)
(U2) and PA power supply (U3).
Power Supply Interface PWB
The Power Supply Interface PWB (A4):
 accepts the ac input voltage and provides input voltage for the PA Power Supply and +12 V
Power Supply.
 distributes LVPS voltage to the RF drive stage and the control/monitor stage.
 distributes PA voltage to the PA PWB and the control/monitor stage.