Philips MX6050D, Service Manual

Page: 18 / 37

TUNER BOARD
TABLE OF CONTENTS
Tuner adjustment table ................................................................... 6-1
Circuit Diagram ............................................................................... 6-2
PCB Layout View (Top) .................................................................. 6-3
PCB Layout View (Bottom) ............................................................ 6-4
Electrical Parts List & Voltage List ................................................. 6-5
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
6.5V
±
1.2V
1.0V
±
0.5V
T002
FM
87.5 - 108MHz
(50kHz grid)
1602KHz
531KHz
T005
1.1V
±
0.5V
FM
612kHz 576kHz
1404kHz
T006
1404kHz VC001
AM
FM - IF
No need
to adjust
FM
10.7MHz, 50mV
continuous wave
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
∆
f =
±
30kHz
V
RF
as low as
possible
200P
short circuit
to block AFC
23
IC001
R220
100nF
24
IC001
450kHz
Connect pin 29 of
IC001 (AM Osc.)
with short wire to
ground (pin 6)
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.
1700KHz
530KHz
AM
530-1710kHz
(10kHz grid)
FM - RF
7.8V
±
0.2V
108MHz
87.5MHz
MAX
mod=1kHz
∆
f=
±
22.5kHz
106MHz
90.1MHz
610kHz
1400kHz
T006
VC002
MW
610kHz
1400kHz
( 21L / 21L / 37S )
8.0V 1HV
±
±
1.1V 0.2V
Max
fo
Symmetric
check
check
check
T005
VC001
L001
MAX
MAX
T001
MAX
T003
V=mV ∆
6-1