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2) CHRONOMINANCE SIGNAL PROCESSING (RECORD)
FBC
BPF1
13
The pure chrominance signal is obtained by BPF1(fsc :4.43MHz) through filters the input signal through
FBC. The gain of ACC AMP is controlled by DC voltage at 13th pin.
The MAIN CONVERTER down-converts the chromiance signal with signal carrier of 4.43MHz to the signal
with signal carrier of 627KHz.
The down-converted signal is again filtered by the LOW PASS FILTER, so the pure chrominance
components are maintained.
Meanwhile, the burst level of the ACC AMP output signal is detected by the burst gate, and it determines
the activation of color killer.
The color killer is also activated when the input signal is SECAM, so the chrominance signal of SECAM is
processed in SECAM-L IC.
3) SECAM COLOR SIGNAL PROCESSING (RECORD)
(A)
SECAM
Signal
Rec Out
12
(a) SECAM composite signal (luminance- chrominance) is applied to the pin 24.
(b) BPF (f
=4.3MHz) removes luminance signal and takes out.
0
(c) Mute gate pulse cuts off the output of the 4.3MHz BPF during the horizontal blanking period to remove
frequency components due to the horizontal sync edge.
(d) Then the chrominance signal is supplied to ACC1 to amplify and stabilize the signal to an optimum level
for processing.
ACC
Main
Conv
AMP
Rec
Rec
Det.
BGA
Chrominance Signal Processing (Record)
(B)
Rec In
4.3M
24
BPF
Sync.
ATI
compress.
(M)
Sync Compress Pulse
SECAM Colour Signal Processing (Record)
C-LPF
Kill
23
(C)
(D)
Mute
ACC1
Gate
Mute Gate Pulse
ACC1 Key Pulse
ACC2
(L)
(K)
19
41
3DQDVRQLF
Pre-amp 10th pin
14
22
(E)
4.3M
LIM
Bell
(G)
1/4
Sync.
(H)
Gate
1.1M
1.1M
a=Bell
BPF
(J)
(I)
18
(F)
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