Anritsu 682XXB - Manual (Page 198)

5-32 682XXB/683XXB MM
A4 Coarse Loop
Error 112 Coarse Loop Osc Failed
Description: The coarse loop oscillator is not phase-locked.
Step 1. Disconnect cable W103 at A4J1 and cable W105 at A4J6.
Step 2. Using a spectrum analyzer, verify the presence of a +5 dBm
±6 dB, 500 MHz signal at the end of cable W103 and a
+3 dBm
±5 dB, 10 MHz signal at the end of cable W105.
G If present, go to step 5.
G If one or both of the signals are not present, go to step 3.
Step 3. Disconnect cable W103 at A3J1 and cable W105 at A3J4.
Step 4. Using the spectrum analyzer, verify the presence of the
+5 dBm
±6 dB, 500 MHz signal at A3J1 and the +3 dBm
±5 dB, 10 MHz signal at A3J4.
G If the 500 MHz signal is present, replace cable W103.
G If the 10 MHz signal is present, replace cable W105.
G If the signals are not present, replace the A3 PCB.
Step 5. Reconnect cable W103 to A4J1 and cable W105 to A4J6,
then disconnect cable W106 at A4J3.
Step 6. Set up the 682XXB/683XXB to generate the CW frequencies
listed in Table 5-12.
Step 7. Using a spectrum analyzer, measure the frequency and am-
plitude of the signal at A4J3 for each of the CW frequencies
generated. In each case, the signal amplitude should be
+4 dBm
±6 dB with sidebands at <–50 dBc.
G If the signals are correct in both frequency and ampli-
tude, go to step 8.
G If the signals are incorrect, replace the A4 PCB.
Step 8. Reconnect cable W106 to A4J3 and run self-test again.
G If error 112 is not displayed, the problem is cleared.
G If error 112 is still displayed, contact your local
ANRITSU service center for assistance.
Table 5-11. Error Message 112
TROUBLESHOOTING
TROUBLESHOOTING TABLES
682XXB/683XXB
CW Frequency
Measured
Frequency at A4J3
2.000 GHz 219.5 MHz ± 10 kHz
2.050 GHz 225.0 MHz ± 10 kHz
2.225 GHz 244.5 MHz
±
10 kHz
Table 5-12. Coarse Loop Frequencies