Keysight N9038A - Page 185

Keysight N9038A MXE Service Guide 185
RF Preselector Section
RF Preselector Section Troubleshooting
4. Turn the instrument self-alignment routine off by pressing System,
Alignments, Auto Align, Off.
Output Signal Routing Verification - Conducted Band
5. Connect a signal generator to the A21 RF Preselector Input assembly
Conducted Band Filtered Input (J200), as shown in Figure 5-4.
6. Tune the signal generator to 10 MHz with an amplitude of −20 dBm.
7. Connect a spectrum analyzer to the A21 RF Preselector Input assembly RF
Output (J101), as shown in Figure 5-4.
8. Tune the spectrum analyzer to a frequency of 10 MHz with a span of
10 MHz.
9. Tune the instrument to a frequency of 10 MHz with a span of 0 Hz by
pressing FREQ, 10 MHz, and SPAN, Zero Span.
10.Verify that the signal level on the spectrum analyzer is at −20 dBm (±3 dB),
as shown in Figure 5-12, allowing for any additional test cable loss.
If the signal level is incorrect the most likely cause of the problem is the
A21 RF Preselector Input assembly itself.
Figure 5-12 A21 RF Preselector Input Assembly - Conducted Band Output
11.Turn on the Marker Delta function of the spectrum analyzer being used.