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7-4
Theory of Operation
3.0
Theory of Operation
3.1
General Information
Your radio has two printed circuit boards: the Controller board, and the Radio Frequency (RF)
board. The Controller board contains the CPU/Control section. The RF board contains the VCO/
Synthesizer section, Transmitter section, Receiver section, Transmitter Audio circuitry, Receiver
Audio circuitry, and Battery section.
3.2
Power Distribution
The above Þgure illustrates the DC distribution throughout the radio board. A battery supplies power
directly to the electronic on/off control. Radio power supply is triggered by the
Power Switch
(On/
Off/Volume control) and
+SW B
is distributed as show in the Þgure. Regulator output 5V is supplied
to the CPU.
+SW B
continues to support the Audio Power AMP, 5V Regulator, TX Regulator until
the radio is turned off.
The radio can be turned off on two ways:
1.
Power Switch
turned-off
2.
Low Battery
When a low battery level is detected by the CPU, it stores the radio personality data to EEPROM
before turning off the radio.
3.3
Power up Sequence
1.
Power supply is turned on by the On/Off/Volume Control (Power Switch).
2.
Power from battery is supplied to the regulator through the switch.
3.
Output (5V) from the regulator is directed to the CPU (Q101).
4.
Q105 resets the CPU (Q101).
5.
The CPU loads radio personality data from EEPROM after the reset.
5V REG
Q204
RX SW
Q211
TX/RX SW
Q210,211
TX REG
Q201,202
RF AMP
Q404
Local AMP
Q416
IF AMP
Q408
IF AMP
Q506
LPF
Q502
HPF
Q505
Audio Power
AMP
Q702
RF PA
Q411
Driver AMP
Q412
MIC AMP
Q602
Sub Audio
LPF Q610
VCO Buffer
Q308
PLL IC
Q323
RF Power
Control
Q419
TX Driver
Q413,414
+ SW B
SAVE SW
Q210
RX +5V
TX +5V
TX/RX SW
Q309,310
TX VCO
Q325
RX VCO
Q324
Battery
Diode
Q126
Reset
Q105
CPU
Q101
EEPROM
Q114
DTMF
Decode
Q120
DA
Converter
Q121
Divide
by 2
Q122
Ripple Filter
Q330
Power
Switch
SW201
Содержание GP2000
Страница 1: ...June 2001 GP2000 Portable Radios Service Manual 6804112J41 O ...
Страница 6: ...vi SAFETY INFORMATION ...
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Страница 31: ...IF Test Box DSK001C702 2 17 12 0 IF Test Box DSK001C702 Figure 2 15 IF Test Box Schematic ...
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Страница 76: ...Section 7 14 Circuit Board Schematic Diagrams and Parts List VHF 136 174 MHz Main Board Top Side ...
Страница 77: ...Circuit Board Schematic Diagrams and Parts List Section 7 15 VHF 136 174 MHz Main Board Bottom Side ...
Страница 78: ...Section 7 16 Circuit Board Schematic Diagrams and Parts List Complete Controller Board Schematic Diagram ...
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