User's Manual

PRELIMINARY
PRELIMINARY PRELIMINARY
PRELIMINARY –
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– Service
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Service Manual
Manual Manual
Manual
DR• CHKD• APPD•
34
turns on Q110 to protect transmitting final amplifier (Q107).
5•Power supply
A 5V reference power supply [5M] for the control circuit is derived from an
internal battery. This reference is used to provide a 5V supply in transmit
mode [5T] ,a 5V supply in receive mode [5R] , and a
5V•
supply common in
both modes [5C] based on the control signal sent from the microprocessor.
6•Control system
The IC403 CPU operates at 7.37MHZ. This oscillator has a circuit that shifts
the frequency according to the EEPROM data.