13.5.2. LINE 2
The modulation signal input from the RF unit is demodulated by IC501.
The audio signal output from pin 39 of IC501 and is input to telephone Line.
Circuit Operation:
pin 39 of IC501 R295 C279 R286 R287 pin 7 of IC251 Q263 pin 12 of PC210
pin 7 of PC210 C270 pin 7 of IC250 C268 R268 Telephone Line
13.6. Line Receiving Signal
13.6.1. LINE 1
The audio signal from line passes through Q162 and Q164, and the signal is input to pin 51 of
IC501.
IC501 modulates the input audio signal to output to the RF unit.
49
Summary of Contents for KX-TC1881B
Page 3: ...2 LOCATION OF CONTROLS Base unit 3 ...
Page 4: ... Handset 4 ...
Page 6: ...6 ...
Page 7: ...7 ...
Page 8: ...4 CONNECTIONS 8 ...
Page 11: ...5 OPERATIONS 5 1 Making Calls 5 1 1 With the Handset 11 ...
Page 12: ...12 ...
Page 13: ...13 ...
Page 14: ...5 1 2 With the Base Unit DIgital Duplex Speakerphone 14 ...
Page 15: ...15 ...
Page 16: ...5 2 Answering Calls 16 ...
Page 17: ...5 2 1 With the Handset 5 2 2 With the Base Unit 17 ...
Page 18: ...6 DISASSEMBLY INSTRUCTIONS 18 ...
Page 20: ...7 ASSEMBLY INSTRUCTIONS 7 1 Assembly the LCD to P C Board Handset 7 2 Replace the RF unit 20 ...
Page 23: ...8 1 Check Power 8 2 Check Sp phone Voice Transmission 8 3 Check Sp phone Voice Reception 23 ...
Page 24: ...8 4 Check Battery Charge 24 ...
Page 31: ...8 7 Check Handset Voice Transmission 31 ...
Page 33: ...NOTE When checking the RF UNIT Refet to Check the RF Unit 8 9 Check Call ID 33 ...
Page 34: ...9 TEST MODE AND ADJUSTMENT 9 1 Test mode flow chart for Base Unit 34 ...
Page 40: ...10 5 EXPLANATION OF BBIC DATA COMMUNICATION 10 5 1 Calling 40 ...
Page 41: ...10 5 2 To Terminate Communication 10 5 3 Ringing 10 5 4 ID Change 41 ...
Page 42: ...11 TERMINAL GUIDE OF IC S TRANSISTORS AND DIODES 11 1 Base Unit 11 2 Handset 42 ...
Page 43: ...12 BLOCK DIAGRAM Base Unit 12 1 Power Supply 12 2 DSP Control 43 ...
Page 58: ...14 BLOCK DIAGRAM Handset 15 CIRCUIT OPERATION Handset 58 ...
Page 62: ...17 CPU DATA Handset 17 1 IC201 62 ...
Page 63: ...18 EXPLANATION OF IC TERMINALS RF Unit 18 1 IC101 63 ...
Page 64: ...64 ...
Page 67: ...20 CABINET AND ELECTRICAL PARTS Base Unit 67 ...
Page 68: ...21 CABINET AND ELECTRICAL PARTS Handset 68 ...
Page 69: ...22 ACCESSORIES AND PACKING MATERIALS 69 ...
Page 88: ...ANT GND ANT VC101 ...
Page 89: ...TEST 10ch 1ch ...
Page 93: ...HANDSET COMPONENT VIEW ANT GND 100 MIC MIC TEST PULL UP 10 10 ANT VC101 SP SP ...
Page 95: ...TX RX IC101 ...