Nokia N72, Руководство по обслуживанию

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8. When the first values have been written to the phone memory, click Next to continue to the next band.
9. Go through all bands.
10. When all bands have been tuned, click Finish, and Close to end the tuning procedure.
Next actions
If the tuning values are not within the limits specified in the "Tx IQ tuning limits" table, start the procedure
again, and check the Tx IQ quality manually.
Tx power level tuning (GSM)
Context
Because of variations in the 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.
In dual or triple band phones, the power level tuning is made for both high and low PA Modes (Power Amplifier
Mode) in the GSM900 band but only for high PA mode in GSM1800/GSM1900 bands
For EDGE transmission, the bias settings of the GSM PA are adjusted in order to improve linearity. This affects
the PA gain and therefore 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-180
RF Troubleshooting and Tuning Guide Nokia Customer Care
Issue 1 COMPANY CONFIDENTIAL Page 7 –31
Copyright © 2006 Nokia. All rights reserved.