Line Amplifier And Side Tone Circuit - Panasonic KX-FP105RS Service Manual

4.5.

LINE AMPLIFIER AND SIDE TONE CIRCUIT

Change from original page 162 (6.8.5. LINE AMPLIFIER AND SIDE TONE CIRCUIT)
1. Circuit Operation
The reception signal output from the line transformer T101 is input to pin (6) of IC101 via C126 and R131, and then the signal
is amplified at pin (7) of IC101 and sent to the reception system at 5dB.
The transmission signal goes through C131 and R137 and enters IC101-pin (2), where the signal is amplified to about 21dB.
Then, it is output from pin (1) of IC101 and transmitted to T101 via C133, R219, R125. If the side tone circuit is not applied, the
transmission signal will return to the reception amplifier via C126, R131, R222 and C229. When the side tone circuit is active,
the signal output from IC101 pin (1) passes through C133, R221, R216, R127, C123, R223 and goes into the amplifier IC101
pin (5). This circuit is used to cancel the transmission return signal.
4.6. CALLING LINE IDENTIFICATION CIRCUIT.......Deleted
Change from original pages 163~164 (6.8.6. CALLING LINE IDENTIFICATION CIRCUIT)
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KX-FP105RS