User Guide

Figure 141 Oscilloscope screen shots (RF)

Introduction to transmitter tuning

In the transmitter, there are two kinds of tunings that can be done: IQ tuning and power level tuning. In general,

different repairs require different tunings. In order to decide which tuning is necessary after a repair, it is

important to understand the functionality of the repaired circuit. In general, it is recommended that if any TX

component is changed, both these tunings be done. All tunings are done in local mode using Phoenix to control

the phone.

As this mobile doesn’t support the EDGE feature, you don’t need to consider operating/tuning the phones in

EDGE mode although Phoenix sometimes has a control selection box to enable EDGE.

Tuning TX/IQ

Context

The tuning must be carried out in all three bands. In addition to Phoenix, a spectrum analyzer (SA) is needed.

Steps

1. Connect the spectrum analyzer (SA) to the RF connector of the module jig. The settings of the SA will depend

on the band to be tuned. The following table summarizes the settings for each of the three bands.

Table 8 Spectrum analyzer settings

GSM900 GSM1800 GSM1900

Center frequency 897.4MHz 1747.8MHz 1880MHz

Frequency span 300kHz 300kHz 300kHz

Resolution Bandwidth 3kHz 3kHz 3kHz

Video Bandwidth 3kHz 3kHz 3kHz

Sweep Time 3 sec 3 sec 3 sec

Trace Type Clear/Write Clear/Write Clear/Write

Detector Type Max Peak Max Peak Max Peak

Reference Level 35dBm 35dBm 35dBm

Marker 1 897.33229 MHz 1747.73229 MHz 1879.93229 MHz

Marker 2 897.4MHz 1747.8MHz 1880MHz

Marker 3 897.46771MHz 1747.86771MHz 1880.06771MHz

2. Open the following two windows in Phoenix:

RM-51

RF troubleshooting Nokia Customer Care

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