User Guide

CCS Technical Documentation
NHM-4
'UDIW &RS\ULJKW1RNLD$OOULJKWVUHVHUYHG 3DJH
7UDQVPLWWHUWURXEOHVKRRWLQJGLDJUDP
)LJXUH7UDQVPLWWHUWURXEOHVKRRWLQJ
TX signal found ?
Check output signal
No
Check output signal level
Tune Tx
Check with RF probe
Start TX power level tuning
Yes
Check all
Yes
No
Check with oscilloscope
Check power control
No
Yes
Synthesizer troubleshooting
TX OK
+32 dbm@897.4 MHz (GSM900)
+29 dBm@1747.8MHz (GSM1800)
OK?
power
levels
OK?
power
levels
OK?
Yes
on 500 MHZ span.
Signal found on
incorrect frequency ?
TX troubleshooting
the signal level on
PA input >=0dBm *
OK?
HAGAR troubleshooting
and check tuned DAC values.
Highest level~700 (GSM900)
Highest level~600 (GSM1800)
Lowest level ~1780
Base level ~150
Major differences ?
No
PA ctrl voltage
>1.5V peak
OK?
loop components
OK?
*When 1kOhm passive probe is used,
correct measurement result by +26dB
Yes
Tune Tx DAC values
TX troubleshooting
Replace faulty
PA&ant. switch
No
Yes
Yes
No
Yes
troubleshooting
components
Yes
No