Nokia RH-21 Series, Руководство по устранению неисправностей

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RH-21
Troubleshooting CCS Technical Documentation
Page 28
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Nokia Corporation Confidential Issue 1 05/2003
Transmitter fault-finding
General instructions for TX troubleshooting
Always use RF cable connected from external RF connector to analyzer via (rf-power)
attenuator. This is important to protect analyzer against excessive rf-power and not to
let leak unwanted rf-power to the cellular frequencies.
Start Phoenix software and select TX mode under testing (AMPS, DAMPS, or TDMA1900).
Select mid channel (383 for AMPS/DAMPS or 1000 for TDMA1900) and power level 2.
Select random data for digital mode of operation.
After any component change, tune the phone with Phoenix autotune SW.
Path of the transmitted signal
AMPS/DAMPS
UEM TX I/Q DA-converters -> I/Q modulator and Digital gain step amplifier (SafariSafari)
-> IF-BPF -> Upcodriver -> BPF -> PA -> Coupler (Power detector) -> Duplex-
filter -> Diplexer -> EXT RF-connector -> Antenna
TDMA1900 (ONLY DUALBANDER)
UEM TX I/Q DA-converters -> I/Q modulator and Digital gain step amplifier (Safari) ->
IF-BPF -> Upcon driver (Safari) ->Balun -> BPF -> PA->Coupler (Power detector)
-> Duplex-filter -> Diplexer -> EXT RF-connector -> Antenna
Power detection and power control circuit belongs under power control part of this
guide.
Fault-finding charts for transmitter
AMPS
Start Phoenix software and set phone to the Analog mode. Set channel 383 and Power
level 2. Connect RF cable to EXT RF connector and connect cable to Spectrum analyze
input, and measure RF level. Notice insertion loss of the cable and attenuations.