Nokia n81 Service Manual page 149

RM-179; RM-223
RF troubleshooting
Tx IQ tuning must be performed for all GSM bands.
Steps
Phoenix service software.
1. Start
2. From the Operating mode drop-down menu, set mode to Local.
3. Choose Tuning→GSM→Tx IQ Tuning .
4. Select Mode: Automatic.
5. Select Band: GSM900 and click Start.
6. Click Next to start GSM1800 band TX IQ tuning.
7. Click Next to start GSM1900 band TX IQ tuning.
8. ClickFinish and then Close.
Next actions
Tuning sliders should be close to the center of the scale after the tuning and within the limits specified in
the following table. If they are not within the limits, check Tx IQ quality manually.
GSM850
I DC offset / Q DC
offset
Ampl
Phase
GSM900
Issue 1
Min
-6
-1
85
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Typ
-4
0
90
Max
6
1
95
Unit
%
dB
°
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