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TX troubleshooting
Check output signal level
+32 dbm@897.4 MHz (GSM900)
+29 dBm@1747.8MHz (GSM1800)
OK?
No
TX signal found ?
Yes
Check with RF probe
the signal level on
PA input >=0dBm *
OK?
Yes
Start TX power level tuning
and check tuned DAC values.
Highest level~700 (GSM900)
Highest level~600 (GSM1800)
Lowest level ~1780
Base level ~150
Major differences ?
No
Check with oscilloscope
PA ctrl voltage
>1.5V peak
OK?
Yes
PA&ant. switch
troubleshooting
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Yes
Check all
power
levels
OK?
No
Check output signal
on 500 MHZ span.
Signal found on
incorrect frequency ?
No
HAGAR troubleshooting
No
*When 1kOhm passive probe is used,
correct measurement result by +26dB
Yes
Tune Tx DAC values
Check power control
loop components
OK?
No
No
Replace faulty
components
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TX OK
Yes
Tune Tx
power
levels
OK?
Yes
Synthesizer troubleshooting
TX troubleshooting
Yes
1+0
Yes
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