Tektronix RSA3408B, Service Manual

Page: 199 / 250

Troubleshooting
RSA3408B Analyzer Service Manual
5- 71
Modify the signal generator
controls as follows:
Frequency: 10 MHz
Level: --30 dBm
Is
the spectrum
displayed with correct
amplitude?
No
Change the reference level from
+20 to --30 dBm in one dB step
on the analyzer.
Yes
Is
the spectrum
displayed with correct
amplitude at the reference level
of +20, +15, +10,
+5, 0, --5, and
--10 dBm?
No
Yes
Replace the A/D board.
Replace
Step attenuator or
A100 Cal generator.
Is
the level of
spurious signal at center
screen --95 dBm
or less?
RF1 band check
Modify the signal generator
controls as follows:
Output: Off
Modify the analyzer controls
as follows:
Center frequency: 100 MHz
Span: 1 MHz
Reference level: 0 dBm
Perform the center offset
calibration
(Refer to page 4--18).
No
Replace
A42 DIFP board.
Modify the signal generator
controls as follows:
Frequency: 100 MHz
Level: --10 dBm
Is
the spectrum
displayed with correct
frequency and
amplitude?
Unplug the coaxial cable W32 on the
RF5 module (See Figure 5--37).
Using another spectrum analyzer,
measure the output at the connector.
Is
the spectrum
measured as follows?
Frequency: 10 MHz
±
10 Hz
Amplitude: --2 dBm
±
3 dB
No
Yes
Replace RF6 module.
No
Yes
Yes
From page 5--70 To page 5--72
Figure 5- 36: Troubleshooting procedure 3 — Signal path (Cont.)