A3 Digital I.f. Troubleshooting - Keysight N8973B Service Manual

Analog/Digital IF Troubleshooting
25 MHz BW IF Section

A3 Digital I.F. Troubleshooting

Verifying the 22.5 MHz Input Power
1. Perform an instrument shut down.
2. Remove the cover of the analyzer. Refer to
3. Turn the instrument over so that the bottom is facing up.
4. Turn on the analyzer and wait for the instrument to complete the boot up
5. Press System, Alignments, Auto Align, Off
6. Press Input, RF Calibrator, 50 MHz
7. Verify the 50 MHz signal is at −25 dBm by pressing MODE/MEAS,
8. To continue verifying press FREQ, Zero Span. Verify the input attenuator
If the analyzer is not in 10 dB of input attenuation press AMPTD,
Attenuation, Mech Atten 10 dB.
Keysight NFA Series Noise Figure Analyzers Service Guide
Replacement Procedures", on page 389
process.
Spectrum Analyzer, OK, FREQ, 50 MHz, Span, 1 MHz, Peak Search on the
analyzer. The marker readout should be 50 MHz at −25 dBm ± 3 dBm. If
this reference signal is measuring incorrectly, see
Troubleshooting (N8973B, 74B, 75B Analyzers)", on page 133
service guide.
on the analyzer is set to 10 dB. (Look near the top of the display near the
center and verify Atten: 10 dB)
Chapter 15, "Assembly
in this service guide.
Chapter 4, "RF Section
in this
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