Tektronix RSA3408B, Service Manual

Page: 201 / 250

Troubleshooting
RSA3408B Analyzer Service Manual
5- 73
Modify the signal generator
controls as follows:
Frequency: 100 MHz
Level: --50 dBm
Is
the spectrum
displayed with correct
amplitude?
No
Change the reference level from
--20 to --42 dBm in one dB step
on the analyzer.
Yes
Replace RF5 module.
Modify the signal generator
controls as follows:
Frequency: 100 MHz
Level: 0 dBm
Change the reference level from
+30 to +10 dBm in one dB step
on the analyzer.
Is
the spectrum
displayed with correct
amplitude?
No
Yes
Replace the step attenuator.
Perform the gain calibration
(Refer to page 4--16).
Does the
display report
any errors?
Unplug the coaxial cable W119 from
J410 on the A100 Cal generator
board (See Figure 5--38). Using
another spectrum analyzer, measure
the output at the connector.
Is
the spectrum
measured as follows?
Frequency: 100 MHz
±
10 Hz
Amplitude: --35 dBm
±
3 dB
No
Yes
Does
the output level
increase to --20 dBm
±
2 dB
transiently when pressing the
Calibrate Gain
side key?
Replace
Step attenuator
Input relay or
A100 Cal generator.
Yes
Replace A100 Cal generator board.
No
Unplug the coaxial cable W13 from
J410 on the A100 Cal generator
board (See Figure 5--38). Using
another spectrum analyzer, measure
the output at the connector.
Is
the spectrum
measured as follows?
Frequency: 400 MHz
±
10 Hz
Amplitude: --1.5 dBm
±
3 dB
Yes
No
Replace RF4 module.
RF2 band check
Modify the analyzer controls
as follows:
Center frequency: 3.6 GHz
Span: 1 MHz
Reference level: 0 dBm
Is
the spectrum
displayed with correct
frequency and
amplitude?
No
Modify the signal generator
controls as follows:
Frequency: 3.6 GHz
Level: --10 dBm
Yes
No
Yes
From page 5--72 To page 5--74
Change the reference level to
+30 dBm on the analyzer.
Figure 5- 36: Troubleshooting procedure 3 — Signal path (Cont.)