User Guide

CCS Technical Documentation Troubleshooting — RF
RH-17
Issue 1 04/2003 Nokia Corporation Confidential Page 59
ware is running, and the phone will search for a pilot. To troubleshoot so that you can
manually control the phone (not in a call), the phone should be in local mode. In local
mode, the phone's software is not running and it will not search for a pilot. To switch
between normal and local modes, use the Phone Control dialog box, shown next. This
setting will be lost if the phone is powered down.
To add a baseband to the AMPS transmitter
To add a baseband test tone to the AMPS transmitter, open the Test Tone dialog box as
shown next and set the parameters as desired.
The DC offset voltages on the I and Q inputs to the modulator are adjusted for minimal
carrier feedthrough (maximum carrier suppression). Initially the DC offsets are set to a
nominal value, and the power of a tone offset in frequency 20 kHz from the carrier is
measured in dBm and recorded as a reference (in this tuning). Then in the next tuning,
the carrier suppression (delta between center tone and tone that is offset 20 kHz) is
measured. If it passes, it is reported in that tuning. If not, the DC offsets are adjusted
until it passes, and the passing value is reported.