Nautel XR6, Operation And Maintenance Manual

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XR6/XR3 Operations and Maintenance Manual Description
Issue 3.1 2013-03-14 Page 1-1
Section 1: Description
Refer to the functional block diagram: “
XR Series Transmitter Block Diagram
” on page 1-7 .
This section provides a high-level description of the transmitter’s key sections. The transmitter
circuitry is subdivided into five basic stages:
• Ac/dc power stage
• Exciter stage
• RF power stage
• RF output filter (includes combiner)
• Control/monitor stage
XR6/XR3 electrical schematics
The descriptions in this section all refer to the XR6/XR3 electrical schematics located at the end of
the
XR6/XR3 Troubleshooting Manual .
Redundancy
The XR6/XR3 features redundancy in all key systems:
• RF power modules (optional fully redundant backup is available)
• Exciters
• Cooling fans
Ac/dc power stage
See electrical schematic
SD-3
. The ac/dc power supply stage contains the input power transformer
that receives the main ac input to the transmitter. It also contains the transmitter’s low voltage power
supplies. Three-phase versions of the ac/dc power supply stage also include a contactor, a three-
phase voltage rectifier, Hall Effect current sensor and B+ power supply/distribution PWB. Single-
phase versions of the ac/dc power stage also include a control transformer, a rectifer/SCR control
assembly and an SCR control/B+ distirbution PWB.