Panasonic KX-FP365CX

45
KX-FP365CX / KX-FM388CX
6.7.5. Line Amplifier and Side Tone Circuit
1. Circuit Operation
The reception signal output from the line transformer T101 is input to pin (2) of IC101 via C108 and R109 and then the signal
is amplified at pin (2) of IC101 and sent to the reception system at 0dB.
The transmission signal is output from CN101 (6) and transmitted to T101 via R114. If the side tone circuit is not applied, the
transmission signal will return to the reception amplifier via C108 and R109. When the side tone circuit is active, the signal
output from IC101 pin (1) passes through R113, C110, C109 and R110 and goes into the amplifier IC101 pin (3). This circuit is
used to cancel the transmission return signal.