Panasonic KX-TC1801B Service Manual ▷ View online
8.4. Signal Flowchart in the Whole System
Reception
CN101 of the base unit is connected to the TEL line, and the signal is input through the bridge diode D101. While talking the
relay (Q121) is turned ON and amplified at the amplifiers Q461, then led to DSP (IC501). DSP generates ADPCM signal. The
ADPCM signal is input to RFIC (IC101) of RF UNIT, and is mixed with pseudo random noise code (PN code) to spread the
spectrum. RFIC outputs FSK modulated RF signal. The RF signal is passed through the balun (T101) and filter (F102) to be
transmitted from the antenna. As for the handset, RF signal from the antenna is input to RFIC passing through filter (F102) and
the balun (T101) to perform the de-spread, then input to DSP (IC201). DSP performs ADPCM decoding to convert the signal
into the voice signal, then it is output to the speaker.
relay (Q121) is turned ON and amplified at the amplifiers Q461, then led to DSP (IC501). DSP generates ADPCM signal. The
ADPCM signal is input to RFIC (IC101) of RF UNIT, and is mixed with pseudo random noise code (PN code) to spread the
spectrum. RFIC outputs FSK modulated RF signal. The RF signal is passed through the balun (T101) and filter (F102) to be
transmitted from the antenna. As for the handset, RF signal from the antenna is input to RFIC passing through filter (F102) and
the balun (T101) to perform the de-spread, then input to DSP (IC201). DSP performs ADPCM decoding to convert the signal
into the voice signal, then it is output to the speaker.
Transmission
The voice signal input from the microphone is led to DSP (IC201). The DSP generates ADPCM signal. As well as the reception,
it is converted into the RF signal by RFIC (IC101). Passing through the balun (T101) and filter (F102), it is transmitted from the
antenna. As for the base unit, RF signal from the antenna is input to RFIC (IC101) passing through filter (F102) and the balum
(T101) to perform the de-spread, then input to DSP (IC201). DSP performs ADPCM decoding to convert the signal into the
voice signal. The voice signal is amplified at the TX amplifier (Q131), then output to the TEL line (CN101) through the relay
(Q121) and bridge (D101).
it is converted into the RF signal by RFIC (IC101). Passing through the balun (T101) and filter (F102), it is transmitted from the
antenna. As for the base unit, RF signal from the antenna is input to RFIC (IC101) passing through filter (F102) and the balum
(T101) to perform the de-spread, then input to DSP (IC201). DSP performs ADPCM decoding to convert the signal into the
voice signal. The voice signal is amplified at the TX amplifier (Q131), then output to the TEL line (CN101) through the relay
(Q121) and bridge (D101).
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KX-TC1801B
8.5. EXPLANATION OF BBIC DATA
COMMUNICATION
8.5.1. Calling
8.5.2. To Terminate Communication
8.5.3. Ringing
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KX-TC1801B
9 FOR SCHEMATIC DIAGRAM
9.1. Base Unit (26 SCHEMATIC DIAGRAM (Base Unit))
Notes:
1. S501: Handset Location Switch
2. DC voltage measurements are taken with voltmeter from the negative voltage line.
This schematic diagram may be modified at any time with the development of new technology.
9.2. Handset (28 SCHEMATIC DIAGRAM (Handset))
Notes:
1. DC voltage measurements are taken with an oscilloscope or a tester with a ground.
2. The schematic diagrams and circuit board may be modified at any time with the development of new technology.
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KX-TC1801B
10 BLOCK DIAGRAM (Base Unit)
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KX-TC1801B
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