Circuit Operations - Panasonic KX-G8300 Service Manual And Technical Manual

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CIRCUIT OPERATIONS
1. BLOCK DESCRIPTION
Given below is a rough block diagram.
When the power ON key on the display unit is pressed, the preheating operation of the magnetron is
completed after 2 min 30 sec, and the radar is placed in the standby mode. When the TX/STBY key on
the display unit is pressed, TX trigger pulses are generated from the signal processor board inside the
display unit, and these are sent to the transmitter in the scanner unit.
In the transmitter, 9410 MHz microwave pulse signals are generated in synchronization with the trigger
pulses, and these are radiated from the antenna into space.
The reflected echo signal from the target is received by the same antenna and amplified in the receiver.
The detected signal from the receiver is sent to the display unit where it is A/D converted and stored in
the memory on the processor board. The write address of the memory is determined by the distance
information (time elapsed from generation of transmission pulses) and antenna bearing data.
The video data read from the memory assigned by the horizontal/vertical address data of the processor
board is sent to the CRT display circuit, and it is indicated at the required CRT position in synchronization
with the horizontal/vertical signals from the processor board.
The characters, markers, EBL, VRM and other data are also displayed on the CRT in a similar way as the
video signals.
Brief Block Diagram
ANTENNA DISPLAY
Video &
Character
Data
CRT Display
Circuit
Processor
Board
Bearing
Data
Bearing/Heading
Pulse
2. CIRCUIT DESCRIPTION
2-1 Display Unit
Refer to the block diagram on the next page.
Processor board (PQUP824ZA)
This board is composed of the 8 major blocks listed below.
1) Video Signal Processor / Character / Mark Generator
2) PLL Circuit
3) TX Trigger Generator
4) Clock Generator
5) Horizontal / Vertical Sync Pulse Generator
6) Alarm Circuit
7) CRT Display Circuit
8) Power Supply
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