Nautel NX50, Troubleshooting Manual

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NX50 Troubleshooting Manual Responding to alarms
Issue 6.0 2019-04-01 Page 1-55
Optimizing RF power module Performance
When swapping damaged RF power modules with new RF power modules, it is possible that
spurs of the fundamental PDM frequency (fc ± 155 kHz) may appear at the output of the
transmitter. If these spurs violate the emissions limits of the region of installation, the problem
may be corrected by initiating the PDM minimization routine, as follows:
1. Turn off (RF Off) and connect the RF output to a suitably rated 50-ohm test load.
2. Using the AUI, set the following items as instructed:
• Overall Mode = Analog AM
• Output Power = rated power
• AM Source = Unused
3. Set the transmitter to its RF On state.
4. Using the AUI, navigate to the PDM minimization routine through Menu -> Factory
Settings -> PDM Settings page, and click on the Start button next to Minimization
Routine.
The PDM minimization routine requires approximately 30 minutes to complete.
CAUTION:
Running the PDM minimization routine will disable the exciter’s SWR protection.
For this reason, you should only run this routine when the transmitter is
connected to a suitably rated 50 ohm test load.