Tektronix RSA3408B, Руководство по обслуживанию

Страница: 202 / 250

Troubleshooting
5- 74
RSA3408B Analyzer Service Manual
Unplug the coaxial cable W307 on
the RF3 module (See Figure 5--37).
Using another spectrum analyzer,
measure the output at the connector.
Is
the spectrum
measured as follows?
Frequency: 421 MHz
±
10 Hz
Amplitude: --32 dBm
±
3 dB
No
Yes
Replace RF2 module.
Unplug the coaxial cable W106 on
the RF3 module (See Figure 5--37).
Using another spectrum analyzer,
measure the output at the cable end.
Is
the spectrum
measured as follows?
Frequency: 3.6 GHz
Amplitude: --38 dBm
±
4 dB
No
Yes
Replace RF3 module.
Check gain and offset values of
the bandpass filter (See
Figure 5--38) in the service menu.
Refer to Reconfiguration of RF
Modules on page 4--33.
Are the
gain and offset values
set correctly?
Enter the correct gain and offset values
of the programmable band-pass filter.
Refer to Reconfiguration of
RF Modules on page 4--33.
Restart the analyzer.
Yes
No
Replace
Bandpass filter or
A100 Cal generator.
Span check
Modify the analyzer controls
as follows:
Center frequency: 100 MHz
Span: 36 MHz
Reference level: 0 dBm
Modify the signal generator
controls as follows:
Frequency: 100 MHz
Level: --10 dBm
Changing the span from 36 MHz to 10 kHz
step by step with the general purpose knob,
check the signal level and the noise floor at
the all span settings.
Is
the signal level
and noise floor
correct?
The analyzer is OK.
Yes
Replace A42 DIFP board.
No
From page 5--73
Figure 5- 36: Troubleshooting procedure 3 — Signal path (Cont.)