17
CIRCUIT OPERATION
2. AUDIO PART
2-1) EE MODE
External AUDIO signal which is input to pin 78 of IC301 is output from pin 96 of IC301 after being ampli-fied
through ALC and Line Amp.
2-2) REC MODE
It will be the REC mode when REC 5V is input to base of Q206,Q202. Input signal will be replaced on the tape
through R/P HEAD after being amplified and modulated with Bias Frequency. Input signal is ampli-fied and
frequency compensated by REC AMP, ie. it means high band compensation in order to match AUDIO HEAD
characteristic. Each modeÕ s peaking frequency will be determined by BIAS element (R, L, C) of REC AMP. OSC
oscillation frequency is 70KHz sinewave, it will be used for tapeÕ s full erasing and AUDIO TRACK erasing.
2-3) PB MODE
The signal which is picked up from AUDIO HEAD is input to EQ AMP, then constant Audio Level will be output by
PB LEVEL fixed resistor after each mode is amplified and frequency is compensated.18H AUDIO output level will
be compensated with receiving Audio 24H(H) control of u-COM. Finally this out-put signal is output through AUDIO
conrol switching IC942, IC943.
Summary of Contents for DQ-K2121N-P
Page 22: ...21 CIRCUIT OPERATION X RAY PROTECTION CIRCUIT DQ K2121N P...
Page 23: ...22 CIRCUIT INFORMATION 1 CONNECTION DIAGRAM DQ K2121N D P...
Page 24: ...23 CIRCUIT INFORMATION 2 POWER SCHEMATIC DIAGRAM DQ K2121N D P...
Page 25: ...24 CIRCUIT INFORMATION 3 RECODER A V SCHEMATIC DIAGRAM DQ K2121N D P...
Page 26: ...25 CIRCUIT INFORMATION 4 SERVO SYSCON SCHEMATIC DIAGRAM DQ K2121N D P...
Page 27: ...26 CIRCUIT INFORMATION 5 FBT CRT SCHEMATIC DIAGRAM DQ K2121N D P...
Page 28: ...27 CIRCUIT INFORMATION 6 LOGIC SCHEMATIC DIAGRAM DQ K2121N D P...
Page 29: ...28 CIRCUIT INFORMATION 7 JACK AUDIO SW SCHEMATIC DIAGRAM DQ K2121N D P...
Page 30: ...29 CIRCUIT INFORMATION 8 MULTIPLEXER SCHEMATIC DIAGRAM DQ K2121N D P...
Page 31: ...30 CIRCUIT INFORMATION 9 MONITOR A V SCHEMATIC DIAGRAM DQ K2121N D P...
Page 55: ...54 COMPONENTS LOCATION GUIDE ON PCB BOTTOM VIEW...
Page 56: ...55 COMPONENTS LOCATION GUIDE ON PCB BOTTOM VIEW...
Page 57: ...56 COMPONENTS LOCATION GUIDE ON PCB BOTTOM VIEW...
Page 58: ...57 COMPONENTS LOCATION GUIDE ON PCB BOTTOM VIEW...
Page 59: ...58 DISASSEMBLY...
Page 78: ...686 AHYEON DONG MAPO GU SEOUL KOREA C P O BOX 8003 SEOUL KOREA DAEWOO ELECTRONICS Corp...
