Panasonic KX-TG2480BXS, Service Manual

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9.3. Signal Flowchart in the Whole System
Reception
CN101 ofthe base unit is connected to the TEL line, and signal is entered through the bridge diode D101. While talking, the
relay (Q104) is turned ON and amplified at the Q150, then led to DSP (IC501). The DSP encodes ADPCM and TDD/TDMA with
FHSS to TX-DATA. The TX-DATA signal is entered to IC901 ofRF UNIT, and modulated to 2.4GHz. The RF signal is fed into
Tx/Rx switch (D104). The RF signal is passed through filter (FL901) and fed to ANTENNA.
As for the handset, RF signal from the antenna passes through filter (FL901), then is routed by Tx/Rx switch (D104) and led to
IC901. The RF signal is amplified by LNA and down-converted to IF signal in IC901. The IF signal passing through internal filter
is demodulated into RX-DATA, then enters DSP (IC201). The DSP performs TDD/TDMA and ADPCM decoding to convert the
RX-DATA into the voice signal, then it is output to the speaker.
Transmission
The voice signal entering from the microphone is led to DSP (IC201). The DSP encodes ADPCM and TDD/TDMA with FHSS
to TX-DATA. The TX-DATA signal enters IC901 ofRF UNIT, and is modulated to 2.4GHz. The RF signal is fed into Tx/Rx switch
(D104). The RF signal is passed through filter (FL901) and fed to ANTENNA.
As for the base unit, RF signal from the antenna passes through filter (FL901), then is routed by Tx/Rx switch (D104) and led
to IC901. The RF signal is amplified by LNA and down-converted to IF signal in IC901. The IF signal passing through internal
filter is demodulated, then enters DSP (IC201). The DSP performs TDD/TDMA and ADPCM decoding to convert the RX-DATA
into the voice signal. The voice signal is amplified at the TX amplifier (Q161), then output to the TEL line CN101 through the
relay (Q104) and bridge (D101).
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KX-TG2480BXS / KX-TGA248BXS