MC1374
Figure 19. A Channel 4 Vestigial Sideband Filter
V
CC
8
9
0
–10
–20
Both transformer windings
4T #23 AWG
8.2pF
2.7k
RL = 75
Ω
close wound on 1/4
on common axis, 3/8
″
ID
″ spacing.
39
pF
–30
24Ω
–40
–50
–60
Ch. 4
Pix
Ch. 4
S
33pF
8.2pF
24Ω
24
Ω
Output
75
Ω
–70
33pF
33pF
100Ω
61
65
69
73
f, FREQUENCY (MHz)
8T #23 AWG
close wound on 1/8″ ID,
knife tuned to trap Channel 3
61.25 MHz.
Figure 20. Audio Pre–Emphasis Circuit
1
RC
25
20
15
2 π
C = 0.0012µF
C
= 0.1
–
µ
+
F
C
1
10
1
14
2
π rC
R
Audio
Input
2
π (r + R)C
5
0
“Flat”
Audio
Input
C
6.0k
Ω
r = 56kΩ
5
Gnd
–5
21
210
2100
21k
f, FREQUENCY (MHz)
1
Pre–emphasis = 75 µs = rC =
2
π (2100 Hz)
Figure 21. Crystal Controlled RF Oscillator
for Channel 3, 61.25 MHz
V
CC
R1
470
C1
0.001
R2 470
R3 470
61.252
MHz
C2
56pF
Ra
180
L1
0.15µH
Rb 18
7
6
MC1374
NOTE: See Application Note AN829 for further information.
8
MOTOROLA ANALOG IC DEVICE DATA
MOTOROLA [ MOTOROLA ]
