2. REC MODE
(1) Signal Flow
In this system, the input signal sources are contained with IF, AV1, AV2/C+ and F.AV. each pin number’s decription is
the same as the below.
The input signals, selected by the input switcher, go through the LPF (at 20KHz) and PNR processor. Additionally, the
selected input signals are supplied to the Normal Audio Unit-Pin 31st. The Normal Audio cab be mixed with the L+R-
Stereo mode, or can be selected with L only-Bilingual mode. The PNR processor compresses the audio signal in
order to reduce the audio noise and enlarge the Dynamic Range.
The FM EMPH(FM Emphasis) emphasizes the higher band of signal. It can restrict the FM back-noise, when the
signal is demodulated. the modified audio signal is modulated by the Modulator unit. It is composed of AUDIO
LIM(Limitter), 1.4MHz & 1.8MHz modulator. The Audio limiter cuts the level of signal to avoid the overmodulation, and
then the limitted signal is modulated with two carriers-1.4MHz : Left Ch, 1.8MHz : Right Ch. The modulated two
signals are mixed by the FM MIX unit. The mix ratio of FM L and R can be adjusted with the software-refer to the
service mode. Finally, REC FM signal put out to the Pin 21st. It is supplied to the Hi-Fi preamp.
(2) Auto Adjustment of the VCO, BPF
In this IC, the FM carrier frequency and BPF are adjusted by the synthesized PLL VCO (Phase Locked Loop Voltage
Control) unit. the Auto adjustment is executed at POWER ON, as using the Fsc-4.43MHz. The Fsc is supplied from
the OSC for Color Sub-carrier in the Video unit. If the adjustment completes successfully, IC’s pin 14th is set the
“HIGH” state-5V. Otherwise “LOW” state-0V. The adjustment of VCO, BPF occurs simultaneouslly.
17
CIRCUIT
AUDIO IN
NORMAL AUDIO
L
R
31
8
INPUT
SW
LPF
LPF
PNR
PNR
FM
EMPH
FM
EMPH
LPF
LPF
1.4M
MOD
AUTO
ADJ
FM
MIX
AUDIO
LIM
AUDIO
LIM
REC FM
LPF
REC FM
LPF
1.8M
MOD
Fsc
21
REC FM OUT
INPUT
CH
L
R
IF
2
1
AV1
44
43
AV2/C+
41
40
F.AV
34
33
Summary of Contents for DV-K88 series
Page 71: ...68 CIRCUIT DIAGRAMS 9 1 Connection Diagram SECTION 9 CIRCUIT DIAGRAM 68...
Page 72: ...69 CIRCUIT DIAGRAMS R819 5 1 9 2 Power Circuit Diagram...
Page 73: ...70 CIRCUIT DIAGRAMS 9 3 Syscon and Logic Circuit Diagram...
Page 74: ...71 CIRCUIT DIAGRAMS 9 4 AV SW Circuit Diagram...
Page 75: ...72 CIRCUIT DIAGRAMS 9 5 IF PDC Circuit Diagram TM...
Page 76: ...73 CIRCUIT DIAGRAMS 9 6 If Module Circuit Diagram A2...
Page 77: ...74 CIRCUIT DIAGRAMS 9 7 If Module Circuit Diagram Nicam...
Page 78: ...75 CIRCUIT DIAGRAMS 9 8 Hi Fi Pre Amp Circuit Diagram...
Page 79: ...76 CIRCUIT DIAGRAMS 9 9 Video Audio Circuit Diagram...
Page 80: ...77 CIRCUIT DIAGRAMS 9 10 Remocon Circuit Diagram...
Page 81: ...SECTION 10 COMPONENTS LOCATION GUIDE ON PCB BOTTOM VIEW 78 P C B LOCATION 10 1 PCB Main...
Page 82: ...80 P C B LOCATION 10 3 PCB Logic DV K8K S S Series DV K86 S S Series DV K82 S S Series...
Page 83: ...81 P C B LOCATION DV K88 S S Series...
Page 84: ...SECTION 11 DISASSEMBLY 83 DISASSEMBLY 11 1 Packing Ass y...
Page 85: ...84 DIAGRAMS DV K88 Series DV K82 Series DV K8K Series DV K86 Series 11 2 Front Panel Assembly...
