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16.2. Transmitter Output Amp Circuit
The signal which is oscillated at TXVCO is amplified by DUP802, whose gain is adjusted by
moving T892.The signal passes through the duplexer and it is radiated from the antenna.
16.3. Bell Detector Circuit
When the Bell signal is input between T/R, the signal of which waveform is shaped through
C118
R123
PC102 (C215
When the CPU detects the Bell signal, pin 19 (20)* repeats High/Low fluctuation and then Line1
(2)* LED3 (LED4)* is flashed.
At this time, if the portable unit is charged, the data from pin 27 is sent to the handset through
the control terminal and CHGC then the portable unit's ringer is on.
If the portable unit is not charged, the data signal generated by pins 27 of the CPU is sent to the
portable unit through RF and then the portable unit's ringer is on.
NOTE:
( )*: In case of Line 2
16.4. Line Interface
In talk status, the L1/L2 RLY output from pin 28 ( 29 )* of IC701 changes to low level, causing
PC101 and Q101(PC201, Q201 and Q207) to turn on and resulting in a line loop. The loop current
flows from D101(+ )
(D201(+)
Q201
between high and low level is output from pin 28 ( 29 )* of the CPU.
This switches the line loop on and off, generating the dial pulse signal.
NOTE:
( )*: In case of Line 2
16.5. DTMF Signal
When the DTMF data from the portable unit is received, the DTMF signal is output from pin 60 of
the CPU and sent to the line through.
R214
Q101
Q102
R110
Q202
R212
D205)* in that order. A pulse signal that repeated switches
PC202)* is input to pin 63 (62)* of the CPU IC701.
D105
36
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