Fig 24 Rx I/Q Signal - Nokia RH-13 Series Troubleshooting Manual

CCS Technical Documentation
4 Measure frequency and peak-to-peak voltage of RX I/Q signal from each test
points. Signal should look like in the picture below:
• If only one or two testpoints shows correct signal and rest of the testpoints are
either deaf or signal is very small, the fault is probably due to Safari ASIC.
• If the signal amplitude is correct but its frequency is something else than 67.71
kHz +/- 3 kHz, you may try to change AFC value (-1024...1023) and see does it
have effect to the frequency. Frequency should be tuned to target value with the
AFC value of +/- 100.
• If the signal amplitude and frequency in all testpoints is correct and signal
amplitude changes when the LNA, MIX2 and BB gains are changed, RX chain is
OK.
• If the signal amplitude in all testpoints is too low (< 1 Vp-p), you have to con-
tinue with RX front-end measurements.
1 Set signal generator frequency to 881.46771 MHz and level to -60 dBm.
2 Set spectrum analyzer settings as following:
• Center frequency: 133.2 MHz, Span: 200 kHz
• RBW: 3 kHz, reference level: -20 dBm
Issue 1 11/02
Figure 24: RX I/Q signal.
ãNokia Corporation
RH-13
Troubleshooting
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