Tektronix RSA3408B, Service Manual

Page: 198 / 250

Troubleshooting
5- 70
RSA3408B Analyzer Service Manual
Set the analyzer as follows:
Center frequency: 10 MHz
Span: 1 MHz
Reference level: 0 dBm
Set the signal generator as follows and
connect it to the analyzer RF input
(Refer to Performance Verification ):
Frequency: 10 MHz
Level: --10 dBm
Is
the spectrum
displayed as follows?
Frequency: 10 MHz
±
10 Hz
Amplitude: --10 dBm
±
1 dB
Replace
A10 A/D board or
A42 DIFP board.
This procedure helps you
determine whether the signal path
is bad.
Baseband check
Unplug the coaxial cable W611 on
the RF6 module (See Figure 5--37).
Using another spectrum analyzer,
measure the output at the connector.
Is
the spectrum
measured as follows?
Frequency: 102.4 MHz
±
10 Hz
Amplitude: +6.5 dBm
±
3 dB
No
Yes
Yes
No
Replace RF6 module.
Reconnect the W611 cable.
Unplug the coaxial cable W360 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: 10 MHz
Amplitude: --20 dBm
±
2 dB
No
Yes
Reconnect the W360 cable.
Unplug the coaxial cable W124 of
the band relay on the bottom (See
Figure 5--38). Using another
spectrum analyzer, measure the
output at the connector.
Is
the spectrum
measured as follows?
Frequency: 10 MHz
Amplitude: --20 dBm
±
2 dB
No
Yes
Replace RF3 module.
Unplug the coaxial cable W121 of
the step attenuator on the bottom
(See Figure 5--38). Using another
spectrum analyzer, measure the
output at the connector.
Is
the spectrum
measured as follows?
Frequency: 10 MHz
Amplitude: --20 dBm
±
1 dB
No
Yes
Replace
Band relay, or
A100 Cal generator.
Replace
Step attenuator,
Input relay, or
A100 Cal generator.
To page 5--71
Figure 5- 36: Troubleshooting procedure 3 — Signal path