Gsm Transmitter Tunings - Nokia N72 Service Manual

RM-180
RF Troubleshooting and Tuning Guide
10. To proceed to the next band, click Next.
11. Go through all bands.
12. To end the tuning, click Finish and Close.

GSM transmitter tunings

Tx IQ tuning (GSM)
Context
• The Tx path branches to I and Q signals at the RF I/Q modulator. Modulator and analog hardware located
after the modulator cause unequal amplitude and phase disturbance to I and Q signal paths. Tx IQ tuning
balances the I and Q branches.
• Tx IQ tuning must be performed on all GSM bands.
Steps
Phoenix service software.
1. Start
2. Choose File→Scan Product.
3. From the Operating mode drop-down menu, set mode to Local.
4. Choose Tuning→GSM→Tx IQ Tuning.
5. From the Band drop-down menu, choose GSM900.
Tx IQ Tuning window, set mode to Automatic.
6. In the
7. Click Start.
Wait until the automatic tuning feature has finished and moved the sliders.
Values are written to the phone memory automatically.
Tuning sliders should be close to the center of the scale after the tuning and within the limits specified
in the following table.
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