Keysight N9038A, Service Manual

Page: 302 / 745

302 Keysight N9038A MXE Service Guide
Front End Control
A15 Front End Control Assembly Troubleshooting
AUX IF Output (Option CR3)
If the instrument is equipped with Option CR3, Auxiliary IF Output, the A15
Enhanced Front End Control assembly will provide the splitting of the IF signal
and routing of it to the AUX IF OUT rear panel connector. This optional signal
path can be seen in the dashed blue line in Figure 8-13 and Figure 8-15 .
The frequency of the Auxiliary IF Output signal will vary depending on the
instrument settings. It will typically be 322.5 MHz, unless the instrument has
option B85 and it is in a configuration that uses the 85 MHz IF Path. In that
case the frequency of the output will be 300 MHz.
The following procedure will verify the AUX IF OUT switching:
1. Turn the instrument on and allow it to complete its boot up process.
2. Switch the instrument into the Spectrum Analyzer mode by pressing
Mode , Spectrum Analyzer .
3. Turn the instrument auto alignment routine off by pressing System ,
Alignments , Auto Align , Off .
4. Turn the 50 MHz Calibrator signal on by pressing Input/Output , RF
Calibrator , 50 MHz .
5. Tune the instrument to a frequency of 50 MHz with a span of 0 Hz by
pressing FREQ Channel , Center Freq , 50 MHz and SPAN X Scale , Zero
Span .
6. Set the input attenuation to 10 dB by pressing AMPTD Y Scale ,
Attenuation , 10 dB .
7. Turn the Auxiliary IF Output on by pressing Input/Output , Output Config ,
Aux IF Out , Second IF (322.5 MHz) .
8. Connect a spectrum analyzer to the rear panel AUX IF OUT port.