User Guide

5. When the values have been written to the phone memory, click the Finish button to end the tuning.

6. Change band to GSM1800 and repeat steps 4 to 5.

7. Change band to GSM1900 and repeat steps 4 to 5.

8. To close the tuning window, click Close.

Next actions

Tuning sliders should be close to the center of the scale after the tuning and within the limits specified in

the table below. If they are not within the limits, check Tx IQ quality manually.

Min Typ Max Unit

GSM900

I DC offset / Q DC

offset

-6 0 6 %

Ampl -1 0 1 dB

Phase 85 90 95

○

GSM1800/GSM1900

I/Q DC -6 0 6 %

Ampl -1 0 1 dB

Phase 86 95 105

○

Tx power level tuning (GSM)

Context

Because of variations at IC process and discrete component values, 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 FEM 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.

RM-86

Nokia Customer Care RF Troubleshooting and Manual Tuning Guide

Page 7 –32 COMPANY CONFIDENTIAL Issue 1