Panasonic KX-TG5771BXS Service Manual page 9

4.1.3. Signal Flowchart in the Whole System
Reception
CN101 of the Base Unit is connected to the TEL line, and signal is enter through the bridge diode D101. While talking, the relay
(Q141) is turned ON and amplified at the Q171, then led to DSP (IC501). The DSP encodes ADPCM and TDD/TDMA with
FHSS to TXMOD. The TXMOD signal is enter to IC701 of RF PART, and modulated to 2.4 GHz. The 2.4 GHz signal is up-
converted to 5.8 GHz RF signal by IC801. The RF signal is amplified by the power amplifier (IC851) and fed to Antennas.
As for the Handset, RF signal from the antenna is amplified by LNA (IC851). The amplified signal is down-converted to 2.4 GHz
signal by IC801 and led to IC701. The 2.4 GHz is down-converted to IF signal in IC701. The IF signal passing through internal
filter is demodulated into RXDATA, then enter to DSP (IC201). The DSP performs TDD/TDMA and ADPCM decoding to convert
the RXDATA into the voice signal, then it is output to the speaker.
Transmission
The voice signal entering from the Handset microphone is led to DSP (IC201). The DSP encodes ADPCM and TDD/TDMA with
FHSS to TXMOD. The TXMOD signal is enter to IC701 of RF PART, and modulated to 2.4 GHz. The 2.4 GHz signal is up-
converted to 5.8 GHz RF signal by IC801. The RF signal is amplified by the power amplifier (IC851) and fed to Antenna.
As for the Base Unit, RF signal from the Antennas is amplified by LNA (IC851). The amplified signal is down-converted to 2.4
GHz signal by IC801 and led to IC701. The 2.4 GHz is down-converted to IF signal in IC701. The IF signal passing through
internal filter is demodulated into RXDATA, then enter to DSP (IC501). The DSP performs TDD/TDMA and ADPCM decoding to
convert the RXDATA into the voice signal. The voice signal is amplified at the TX amplifier (Q161), then output to the TEL line
CN101 through the relay (Q141) and bridge (D101).
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KX-TG5771BXS/KX-TGA570BXS