User Guide

NPL-4/5

Nokia Customer Care

additionally required.

• In general repairs in the RX front-end always require RX Calibration and

Rx Band Filter Calibration for all three bands.

• Repairs in the PLL circuit always require RX Calibration of the low band.

If the RF ASIC was replaced all calibrations mentioned above have to be done.

Semi-automatic Calibrations & Measurements - step by step: RX/TX and

GSM-Bands

RX tunings

The RX Calibration has to be performed to determine gains at different gain settings in

the RF ASIC. The calibration must be done in all three bands:

• NPL-5:GSM900, GSM1800, GSM1900

• NPL-4:GSM850, GSM1800, GSM1900

RX Calibration requires an external RF signal generator. Most of the radio communica-

tion testers like CMD 55 or CMU 200 can be used also as RF signal generators, generat-

ing continuous RF signals (CW signal) with defined levels and frequencies.

Rx calibration GSM850 or GSM900

• NPL-5 (EU- variant) has to be calibrated on GSM 900.

• NPL-4 (US- variant) has to be calibrated on GSM 850.

Open the window “Rx Calibration” in Phoenix Service Software as follows:

- Select → Tuning (Alt-U)

- Select → Rx calibration (Alt-C)

The necessary band selection is made by Phoenix automatically in the low band.

- Connect an RF signal generator to the antenna port of the test jig respectively to the

phone.

The setup should now look like this: