CF2
CF3
mark
– 5 –
– 6 –
ICF-18
SECTION 5
DIAGRAMS
5-1.
SCHEMATIC DIAGRAM
5-2.
PRINTED WIRING BOARDS
Mark
Center frequency
red
10.70 MHz
blue
10.67 MHz
orange
10.73 MHz
black
10.64 MHz
white
10.76 MHz
HOW TO CHANGE THE CERAMIC FILTERS
This model is used two ceramic filters of CF2, CF3.
You must use same type of color marked ceramic filters in order to
meet same specifications.
Therefore, the ceramic filter must change two pieces together since
it's supply two pieces in one package as a spare parts.
• IC Block Diagram
IC1
CXA1019S
1
2
3
4
5
6
7
8
9
10
15
14
13
12
11
FM
DISCRIMINATOR
AF POWER AMP
AM FE
FM IF
TUNING
METER
AM IF DET AGC
FM FE
23
22
21
20
24
25
19
18 17 16
29 28 27 26
30
GND
GND
AF OUT
VCC
RIPPLE
FIL
TER
AF IN
DET OUT
AFC AGC
AFC AGC
IF GND
METER
N.C
FM IF IN
AM IF IN
FM/AM BAND
SELECT
FM/AM
IF OUT
N.C
FE GND
AM RF IN
FM RF
REG OUT
FM OSC
FM RF IN
AFC
AM OSC
VOL
NF
FM DISCRI
GND
GND
Note on Schematic Diagram:
•
All capacitors are in µF unless otherwise noted. pF: µµF 50
WV or less are not indicated except for electrolytics and
tantalums.
•
All resistors are in
Ω
and
1
/
4
W or less unless otherwise
specified.
•
¢
: internal component.
•
: panel designation.
•
: B+ Line.
•
: adjustment for repair.
•
Power voltage is dc 3 V and fed with regulated dc power
supply from battery terminal.
•
Voltages are dc with respect to ground under no-signal
(detuned) conditions.
no mark : FM
(
) : AM
[
] : FM/AM
•
Voltages are taken with a VOM (Input impedance 10 M
Ω
).
Voltage variations may be noted due to normal production
tolerances.
•
Signal path.
: FM
Note on Printed Wiring Board:
•
: parts extracted from the component side.
•
p
: parts mounted on the conductor side.
•
¢
: internal component.
•
: Pattern from the side which enables seeing.
