Transmitter Troubleshooting; General Instructions For Tx Troubleshooting; Path Of The Transmitted Signall; Fault Finding Charts For The Transmitter - Nokia NPC-1 Series Troubleshooting Instructions

NPC-1
Troubleshooting Instructions
TDMA800
Since the same physical signal path is used for both analog and digital modes at the
lower band, there is no need for additional troubleshooting in the digital mode. So if the
digital mode at the lower band is not working properly, start the analog mode trouble-
shooting.

Transmitter Troubleshooting

General instructions for TX troubleshooting

Always use an RF-cable connected from an external RF-connector to the analyzer via
(RF-power) attennuator. This is important to protect the analyzer against excessive RF-
power and not to allow leakage of undesired RF-power into the cellular frequencies.
1 Start the Phoenix-software and select the TX mode under Testing (AMPS,
DAMPS).
2 It is useful to select the mid channel (383 for AMPS/DAMPS) and the power level
2.
Note: After any component change, tune the phone with the Phoenix autotune SW .
Path of the transmitted signal
AMPS/DAMPS
UEM TX I/Q DA-converters -> I/Q modulator and Digital gain step amplifier (SAFARI) ->
IF-BPF -> Upconverter+driver -> BPF -> PA -> Coupler (Power detector) -> Duplex-filter
-> Diplexer -> EXT RF-connector -> Antenna

Fault finding charts for the transmitter

AMPS
1 Start the Phoenix-software and set the phone to the Analog mode by using RF
Test UI.
2 Set the channel to 383 and the power level to 2.
3 Connect the RF-cable to the Ext RF connector.
4 Connect the cable to the Spectrum analyzer input.
5 Measure the RF level.
Note: Insertion loss of the cable and attenuations.
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ãNokia Corporation
PAMS Technical Documentation
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