Philips FWD 792, Service Manual

Page: 39 / 47

TUNER BOARD
TABLE OF CONTENTS
Tuner Adjustment Table .................................................................. 7-1
Circuit Diagram .............................................................................. 7-2
PCB Layout ......................... ........................................................... 7-3
TUNER ADJUSTMENT TABLE
Waverange Input frequency Input Tuned to Adjust Output Scope/Voltmeter
VARICAP ALIGNMENT
AM IF
AM RF
3)
108MHz
87.5MHz check
7.5V 1V
1.4V 0.2V
T002
FM
87.5 - 108MHz
(50kHz grid)
1602KHz
531KHz T005
FM
612kHz 612kHz
1404kHz
T006
1 0 0 C V z H k 4 0 4 1
AM
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)
2)
RC network serves for damping the IF-filter while
adjusting the other one.
3) For AM RF adjustments the original frame antenna has to be used!
.
x
a
m
symmetric
f
o
.
x
a
m
symmetric
f
o
0
2
2
R
100nF
24
IC001
450kHz
Connect pin 6 of
IC001 (AM Osc.)
with short wire to
ground (pin 4)
AM AFC
MW
f = 15kHz
V
RF
= 3mV
Use Service Testprogram. By selecting the TUNER TEST test frequencies will be stored as preset frequencies automatically.
MW
531-1602kHz
(9kHz grid)
FM - RF
7.2V 1V
108MHz
87.5MHz
MAX
mod=1kHz
f= 22.5kHz
106MHz
90.1MHz
MW
( 98/ 55/ 51 )
check
check
VC001
L001
MAX
MAX
T001
MAX
T003
V=mV
530-1700kHz
(10kHz grid)
1700KHz
531KHz
check
T005
1.1V 0.2V
7.2V 1V
1.1V 0.2V
1000kHz
600kHz
1000kHz
600kHz T006
VC001
Remark: The module is not intend to be repaired on component level. Circuit Diagrams and
Printed Board drawings are published for orientation only. The whole Tuner Board
Ass'y can be orderd with 12nc: 9940 000 05366 for /37/55/98.
7-1 7-1