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7-1
TUNER BOARD
TABLE OF CONTENTS
Tuner Adjustment Table .................................................................. 7-1
Circuit Diagram (/98 & /55 ver.) ...................................................... 7-2
PCB Layout (/98 & /55 ver.) ........................................................... 7-3
Electrical Parts List & Voltage List ................................................. 7-4
TUNER ADJUSTMENT TABLE
Waverange
Input frequency
Input
VARICAP ALIGNMENT
FM
87.5 - 108MHz
(50kHz grid)
MW
531-1602kHz
(9kHz grid)
530-1700kHz
(10kHz grid)
( 98/ 55/ 51 )
FM - RF
108MHz
FM
87.5MHz
mod=1kHz
f= 22.5kHz
AM IF
450kHz
AM
f = 15kHz
V
= 3mV
Connect pin 6 of
RF
IC001 (AM Osc.)
with short wire to
AM AFC
ground (pin 4)
V=mV
MW
3)
AM RF
1404kHz
612kHz
MW
1000kHz
600kHz
Use Service Testprogram. By selecting the TUNER TEST test frequencies will be stored as preset frequencies automatically.
1)
If sensitivity of frequency counter is too low adjust to max. channel separation
(input signal: stereo left 90% + 9%, adjust output on right channel to minimum)
3)
For AM RF adjustments the original frame antenna has to be used!
7-1
Tuned to
Adjust
Output
Scope/Voltmeter
108MHz
7.5V 1V
check
87.5MHz
check
1.4V 0.2V
1602KHz
7.2V 1V
check
T005
531KHz
1.1V 0.2V
1700KHz
check
7.2V 1V
531KHz
T005
1.1V 0.2V
106MHz
VC001
MAX
MAX
90.1MHz
L001
IC001
T001
24
100nF
T002
MAX
f
o
symmetric
T003
1404kHz
VC001
612kHz
T006
MAX
1000kHz
VC001
f
o
symmetric
600kHz
T006
2)
RC network serves for damping the IF-filter while
adjusting the other one.
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