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Analog/Digital IF Troubleshooting
25 MHz BW IF Section
A2 Analog I.F. Troubleshooting
There are three steps to verify the A2 Analog I.F. Assembly.
— Measure the input power and frequency accuracy of the 322.5 MHz signal
(from the A13 RF Front End assembly or the A15 Front End Control
Assembly).
— Measure the output power and frequency accuracy of the 22.5 MHz signal
(to the A3 Digital I.F. Assembly)
— Measure the 300 MHz input LO signal (from the A16 Reference Assembly)
Verifying the 322.5 MHz Input Power
1. Turn the instrument off.
2. Remove instrument cover. Refer to Chapter 14, “Assembly Replacement
Procedures” in this service guide.
3. Turn on the N9020A Signal Analyzer and wait for the instrument to
complete the boot up process.
4. Press System, Alignments, Auto Align, Off.
5. Press Input/Output, RF calibrator, 50 MHz.
6. Verify the 50 MHz signal is at −25 dBm on the analyzer display by pressing
FREQ, 50 MHz, SPAN, 1 MHz, Peak Search on the N9020A. The marker
readout should be 50 MHz at −25 dBm ± 3 dBm. If this reference signal is
measuring incorrectly, see Chapter 4, “RF Section Troubleshooting”in this
service guide.
7. To continue verifying press SPAN, Zero Span. Verify the input attenuator
on the N9020A is set to 10 dB. Look near the top of the display near the
center and verify that Atten: 10 dB is visible. If needed change the input
attenuator by pressing AMPTD, Attenuation, 10 dB on the analyzer.
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