Agilent Technologies 8935 Series, Manual

Page: 83 / 343

82 Chapter 3
Troubleshooting
Manual Troubleshooting Procedures (Step 4)
The assemblies that require a periodic calibration procedure are:
• A2A100 CDMA Generator Reference
• A2A130 RF Input/Output
• A2A120 LO IF/IQ Modulator
• A2A200 100W Attenuator
• A2A34 Data Buffer
• A2A80 Audio Analyzer 1
• A2A40 Audio Analyzer 2
• A2A33 Measurement
• A2A44 Modulation Distribution
Generally, these assemblies can be swapped without an immediate need
of recalibration. In some cases though, a recalibration may be necessary
to properly troubleshoot the instrument.
Further Isolating RF Failures
Isolating failures in the RF assemblies of the Test Set can be difficult.
One problem occurs when the diagnostics use the built-in RF analyzer
to test the built-in RF source, and vice versa. This is necessary to make
the diagnostics self-contained, that is, they run without external
equipment.
Some general-purpose, RF test equipment will be needed:
• RF signal generator
• RF modulation analyzer or spectrum analyzer.
Isolating the RF Analyzer
The RF Analyzer function uses the following assemblies. Refer to
Figure 3-18 on page 83 and the block diagrams in Chapter 10 , “Block
Diagrams,” on page 283 .
• A2A115 Downconverter
• A2A21 Receiver
• A2A22 Receiver Synthesizer
• A2A20 Spectrum Analyzer