Nautel XR6, Operation And Maintenance Manual

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XR6/XR3 Operations and Maintenance Manual Test and adjustment
Issue 3.1 2013-03-14 Page 5-1
Section 5: Test and adjustment
This section contains test and adjustment procedures for the XR6/XR3 transmitter. The test
procedures use integral meters and precision test/monitoring equipment. The test procedures
contain routine adjustment instructions to bring the parameter being tested within defined limits,
where appropriate.
Follow all instructions in the order presented, particularly for personnel who are not familiar with
detailed circuit theory and may not realize the impact a specific adjustment can have on other steps.
These adjustments should be performed during initial turn-on and after major repairs or a frequency
change.
Test equipment required
To perform the procedures outline in this section you will need:
• a 50
Ω
dummy load that is able to dissipate the RF power being applied to it (6 kW carrier, 9
kW total)
• an oscilloscope
• a digital multimeter
• an audio signal generator
• a modulation monitor
Test prerequisites
Complete the following steps before performing any testing or adjustment procedures:
1. Verify that nothing affecting the RF power stage has been changed since the initial start-up
procedure (see “Turning on the transmitter” of the XR6/XR3 Installation Manual ) was
completed.
2. Switch off the ac power at the service entrance.