Installation guide

Troubleshooting
Troubleshooting Performance Test Problems
1-96
Power Level Accuracy If the problem shows up at high power levels ≥−55 dBm:
•Perform:
— Digital Gain Adjust Calibration
— Bypass Gain Adjust Calibration
— ALC Modulation Driver Bias Calibration
— ALC Calibration
— Power Level Accuracy, High Power Calibration
• If still failing, at high power levels ≥−55 dBm, refer to:
— “Troubleshooting Unlevels and the RF Path” on
page 1-73
If the problem shows up only at low power levels <−55 dBm:
•Perform:
— Power Level Accuracy, Low Power Calibration
— Check the AT1 step attenuator
and all semi-rigid cabling in the RF path.
Timebase Aging Rate
(Manual Test - Option UNJ, Option 506, or
Option 1E5 Only)
•Perform:
— Timebase DAC Calibration
• If failing, troubleshoot the following assemblies:
— A18 Reference
Digital Modulation Level Accuracy • Perform:
— All I/Q calibrations
• If failing, troubleshoot the following assemblies:
— A13 Output (fails only ≤ 4 GHz)
— A14 Extended Frequency Output (Option 506)
(fails only > 4 GHz)
Table 1-40 Troubleshooting Performance Test Problems
Performance test that is failing... Action to perform...