User Guide

RH-23 Company confidential
CCS Technical Documentation
Page 10 Nokia Corporation. Issue 1 03/2004
Transmitter troubleshooting diagram
Figure 3: Transmitter troubleshooting
Yes
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No Yes
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TX Troubleshooting
Check output signal level:
+32…+33dBm@897.4MHz(GSM900)
+29…+30dBm@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: ~ -1…+5dBm
OK?
Helgo
troubleshootin
g
Start TX power level tuning and check tuned coefficient values:
Highest level ~0.655…0.831(GSM900); ~0.567…0.782(GSM1800&1900)
Lowest level ~0.166…0.196(GSM900); ~0.176…0.225(GSM1800&1900)
Base level ~0.137…0.166(GSM900); ~0.132…0.161(GSM1800&1900)
Major differences?
Tune TX coefficient
values
Check control voltage with
oscilloscope:
PA Ctrl voltage >1.5V peak
OK?
Check control loop
components
OK?
Replace Helgo
PA & Antenna Switch
troubleshooting
Replace faulty
com
p
onents
)
)
)
(GSM1800)