User Guide

RH-20 Company confidential
CCS Technical Documentation
Page 16 Nokia Corporation. Issue 1 10/2003
Figure 8: Transmitter EDGE troubleshooting
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TX EDGE Troubleshooting
Check output signal level:
+24…+30dBm@897.4MHz(GSM900)
+22…+29dBm@1747.8 and 1880MHz
(GSM1800&1900)
OK?
Check
all power
levels,
OK?
TX OK
Tune
TX power
levels,
OK?
TX si
g
nal found?
Check output signal
on 500MHz span
Signal found on incorrect
frequency?
Synthesizer
troubleshootin
g
Check with RF probe signal level on
PA input:
~-8dBm@PCL=8 (GSM900)
~-10dBm@PCL=2 (GSM1800&1900)
OK?
Helgo EDGE
troubleshootin
g
Start TX Edge power level tuning and check tuned coefficient values:
Highest level ~0.684…0.841(GSM900); ~0.763…0.860(GSM1800&1900)
Lowest level ~0.333…0.420(GSM900); ~0.323…0.362(GSM1800&1900)
Base level ~0.273…0.313(GSM900); ~0.244…0.313(GSM1800&1900)
Major differences?
Tune TX coefficient
values
Check control voltages with
oscilloscope:
Pa Iref ~2V peak (GSM900)
Pa Iref ~2.1V peak (GSM1800@1900)
Mode ~1.8V OK?
Check EDGE control
loop components
OK?
Replace Helgo
PA & ant switch
EDGE troubleshooting
Replace faulty
com
p
onents