Nokia 7250, 7250i Instruction De Maintenance
CCS Technical Documentation
NHL-4J/
Issue 2 06/03
Copyright Nokia. All rights reserved..
Page 59
TX I/Q Tuning
Spectrum analyzer needed
Tx IQ Tuning allows changing the Tx I DC Offset, Tx Q DC Offset, Amplitude difference
and Phase difference
and Phase difference
Must be done separately on all bands!
Start TX I/Q Tunung at EGSM (GSM900), then continue at GSM1800 band and finally on
the GSM1900 band
the GSM1900 band
Remember to take jig and cable attenuations into account!
Select Maintenance => Tuning => Tx_IQTuning
The tuning is done by setting each of the sliders to desired value.
The sliders can be changed only when the tuning is ongoing.
The order of tuning should be same as the order of the sliders e.g. the Tx I DC Offset is
tuned first and Phase difference is tuned last.
tuned first and Phase difference is tuned last.
Use <= , =>, PgUp or PgDn keys
If “Load from Product” is checked, the values will be loaded from the current settings of
the product when tuning starts.
the product when tuning starts.
If “Save to Product” is checked, the values will be saved to the product when tuning
stops.
stops.
Uncheck them for testing purposes.
Tx IQ Tuning limits are the same for all bands (GSM900, GSM1800 and GSM1900):