Transmitter Fault-Finding; General Instructions For Tx Troubleshooting; Path Of The Transmitted Signal; Fault-Finding Charts For Transmitter - Nokia RH-21 Series Troubleshooting Manual

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RH-21

Troubleshooting

Transmitter fault-finding

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.

AMPS/DAMPS

UEM TX I/Q DA-converters -> I/Q modulator and Digital gain step amplifier (SafariSafari)

-> IF-BPF -> Upconverter+driver -> 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 -> Upconverter + 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.

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.

Page 28

Nokia Corporation Confidential

CCS Technical Documentation

Issue 1 05/2003

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