Transmitter; General Instructions For Tx Troubleshooting; Amps/Tdma; Gsm850 - Nokia RH-13 Series Troubleshooting Manual

Transceivers

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CCS Technical Documentation

LNA gain step function can be checked by measuring signal level at L803 and turning ON

and OFF the LNA using Phoenix. The gain should change by 20...30 dB.

Transmitter

Always use an RF-cable connected from an external RF-connector to analyzer via (rf-

power) attenuator. This is important to protect analyzer against excessive RF power and

not allow leakage of undesired RF power into cellular frequencies.

After any component change tune the phone with Phoenix auto tune SW.

Start Phoenix-software and select TX mode under testing (AMPS, DAMPS or TDMA1900).

It is useful to select mid channel (383 for AMPS/DAMPS or 1000 for TDMA1900) and

power level 2. Select random data for digital mode of operation.

Start Phoenix-software and select GSM RF Control, Band GSM850, Active unit TX, PL7,

Ch189 and TX data type random.

Start Phoenix-software and select GSM RF Control, Band GSM1900, Active unit TX, PL0,

Ch661 and TX data type random.

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

Dual TX IF-BPF -> Up converter (mixer -> C904 -> driver) -> BPF -> PA -> Power detec-

tor -> Duplex-filter -> Diplexer -> EXT RF-connector -> Antenna

Issue 1 11/02

Figure 35: IF signal level.

ãNokia Corporation

RH-13

Troubleshooting

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