Service Manual
Page 1.2
2 ~ SERVICE PHILOSOPHY
2.3
S
OFTWARE
P
OLICY
.....................................................................................................................2.29
3.
DISASSEMBLY.............................................................................................................................3.30
4.
TECHNICAL DESCRIPTION...........................................................................................................4.1
4.1
RECEIVER.....................................................................................................................................4.1
4.1.1 Front-End Filters and RF Amplifier.....................................................................................4.1
4.1.2
First Mixer and IF Section ..................................................................................................4.1
4.1.3 Quadrature Demodulator....................................................................................................4.1
4.1.4 Receiver Audio Processing ................................................................................................4.2
4.2
T
RANSMITTER
...............................................................................................................................4.3
4.2.1 Drivers and PA Stages .......................................................................................................4.3
4.2.2 Power Control.....................................................................................................................4.3
4.2.3
Antenna Changeover and Harmonic Filter.........................................................................4.3
4.2.4 Transmitter Audio Processing ............................................................................................4.3
4.3
F
REQUENCY
S
YNTHESISER
............................................................................................................4.5
4.3.1 General...............................................................................................................................4.5
4.3.2 PLL .....................................................................................................................................4.5
4.3.3 VCO’s .................................................................................................................................4.5
4.3.4 Negative Bias Generator and Loop Filter...........................................................................4.5
4.3.5 Phase Modulator ................................................................................................................4.5
4.3.6 Reference Oscillator...........................................................................................................4.6
4.4
CONTROL .....................................................................................................................................4.7
4.4.1 DSP and PLA .....................................................................................................................4.7
4.4.2
DSP Clock Oscillator ..........................................................................................................4.7
4.4.3 PLA PWM ...........................................................................................................................4.7
4.5
M
EMORY
.......................................................................................................................................4.8
4.6
P
OWER
S
UPPLIES
.........................................................................................................................4.8
4.6.1 Power On Function.............................................................................................................4.8
4.6.2 Power Supplies...................................................................................................................4.9
4.6.2.1 5V Regulator U900.................................................................................................4.9
4.6.2.2 5V Regulator U901.................................................................................................4.9
4.6.2.3
3.3V Regulator U902/Q918....................................................................................4.9
4.6.2.4 2.5V Regulator U903..............................................................................................4.9
4.6.2.5 Negative Power Supply U904E/F...........................................................................4.9
4.6.2.6
Switched Battery ....................................................................................................4.9
4.7
K
EYBOARD AND
D
ISPLAY
(MMI) ..................................................................................................4.10
5.
ALIGNMENT (LEVEL 3 SERVICE ONLY)......................................................................................5.1
5.1
T
EST
E
QUIPMENT
..........................................................................................................................5.1
5.2
T
EST
S
ET
-
UP
................................................................................................................................5.3
5.2.1 COMMS Set up ..................................................................................................................5.3
5.2.2 Radio Preparation ..............................................................................................................5.5
5.2.3
Alignment Procedure..........................................................................................................5.6
5.2.3.1 VCO DAC Alignment..............................................................................................5.6
5.2.3.2 TCXO (Radio Netting Adjustment).........................................................................5.7
5.2.3.3
Rx Front End ..........................................................................................................5.8
5.2.3.4 Mute/Audio Balance Adjustment ............................................................................5.9
5.2.3.5 RSSI .....................................................................................................................5.10
5.2.3.6
Tx Power ..............................................................................................................5.11
5.2.3.7 Modulation............................................................................................................5.12
5.2.3.8 Programming........................................................................................................5.13
5.2.3.9 Customers Radio Configuration Data ..................................................................5.13
6.
REPLACEABLE PARTS...............................................................................................................6.14