Table of Contents
Advertisement
TK-701S
The detected audio frequency signal output from U13
is amplitude-limited by diode limiters D13 and D14:
both
131555,
and
amplified
by Q15:
2SC1815(Y),
then
coupled through the PLL unit for optional tone signalling
use.
The audio signal returned from the PLL unit is de-
emphasized
by R62 and C135, and is actively high-pass
Bt
?
20.945MHz
1
|
.
18
0.0047
Ot
ag O
2
.
¢
"nour
33P
2
Le
120P
2
3
=
17
fo)
2)
a
Ceramic
3
©
16
~
Filter
OTt
2
2 O—
Mute
CFV
1.8K
@
4550
4
8
°
15
—O
®
Scan Control
8
5
1-4
O'4 squeich input
35 Limiter
Ol
6
=
53
' L
L
Sek
Inverting
Op Amp
O.l
7
50K
~~
12
(Filter)
[
IOP:
8k *
aff
1
"
ll
ie
Demodulator
ry
O
a
9
10
_
re
-O-— Recovered
Audio
ISP
tT
Fig. 4-2 Functional Block Diagram of U13 (MC3359P)
ANT
Antennd
Oo-——
sw.
~|
@PF
BPF
- 120dBm
-0.5d8
-0.7dB
+10dB
-2dB
+ 76B
-2dB
MCF
UI3
21F 15B
MC3359P
BPF
L
3
5!
10
-6dB
Ceramic
yidg
filter
20.94 5MHz
Z3)
il
O+10dBn
RXO
PLL
unit
PLL
unit
SP
O
O
O
©
©
DIZ.
AFI
AFO
AVO
4w4n.
ad
ci35
0.64V
I
olev
abmy
Fig. 4-3 Receiver Block Diagram
4-2
Advertisement
Table of Contents
