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Next action
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.
Min
Typ
Max
Unit
GSM900
I DC offset / Q DC
offset
-6
-4
6
dB
Ampl
-1
0
1
dB
Phase
85
90
95
dB
GSM1800/GSM1900
I/Q DC
-6
0.5
6
dB
Ampl
-1
0
1
dB
Phase
95
100
110
dB
Tx power level tuning (GSM)
Context
Because of variations at the IC (Integrated Circuit) process and discrete component values, the actual
transmitter RF gain of each phone is different. Tx power level tuning is used to find out mapping factors
called 'power coefficients’. These adjust the GSM transmitter output power to fulfill the specifications.
For EDGE transmission, the bias settings of the GSM PA are adjusted in order to improve linearity. This affects
the PA gain and hence the power levels have to be aligned separately for EDGE transmission.
Tx power level tuning has to be performed on all GSM bands.
Steps
1. Connect the phone to a spectrum analyzer.
2. Start
Phoenix
service software.
3. From the Operating mode drop-down menu, set mode to Local.
4. Choose Tuning
→
GSM
→
Tx Power Level Tuning .
RM-70
Nokia Customer Care
RF Troubleshooting and Manual Tuning Guide
Page 7 –26
COMPANY CONFIDENTIAL
Issue 1
Copyright © 2005 Nokia. All rights reserved.
Содержание 7370
Страница 183: ...8 System module Nokia Customer Care Issue 1 COMPANY CONFIDENTIAL Page 8 1 Copyright 2005 Nokia All rights reserved ...
Страница 207: ...9 Schematics Nokia Customer Care Issue 1 COMPANY CONFIDENTIAL Page 9 1 Copyright 2005 Nokia All rights reserved ...
Страница 221: ...Glossary Nokia Customer Care Issue 1 COMPANY CONFIDENTIAL Page Glossary 1 Copyright 2005 Nokia All rights reserved ...