Philips FWD570/21M - TUNER ADJUSTMENT TABLE; Varicap, FM RF, and AM IF;RF Alignment

TUNER BOARD (9940 000 00873)
TABLE OF CONTENTS
Tuner Adjustment Table ..................................................................6-1
Circuit Diagram ............................................................................... 6-2
PCB Layout Top View ..................................................................... 6-3
PCB Layout Bottom View ............................................................... 6-4
6-1
6-1
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
1.1V 0.2V
FM
612kHz612kHz
1404kHz
T006
1404kHz VC001
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!
max.
symmetric
f
o
max.
symmetric
f
o
R220
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
(10kHz grid)
FM - RF
7.2V ± 1V
108MHz
87.5MHz
MAX
mod=1kHz
∆f=± 22.5kHz
106MHz
90.1MHz
MW
( 21L / 21L / 37S )
±
check
check
VC001
L001
MAX
MAX
T001
MAX
T003
V=mV
∆