Philips 28PW9618, Service Manual

Page: 121 / 172

Electrical Alignments
EN 121 EM6E 8.
8.2.4
Wireless Receiver Alignments
Figure 8-6 Wireless receiver test circuit
Figure 8-7 Functional check and alignments table
wireless receiver test circuit
68 E
50 E
68 E
To RX input
RF Gener
ator
DUT
LF Voltmeter
e.g. PM2534
CL36532008_068.eps
080503
Wireless Receiver functional check and adjustment table TV Mark 3 (EM6) versions
Powersupply
check
Measurement
ground
testpoint Scope / Voltmeter
F702 +10V ± 0.1V
F740 + 5.2V ± 0.5V
F705 + 8V ± 0.5V
F707 + 8V ± 0.5V
F708 +3.6V ± 0.2V
F709 +7.75V ± 0.5V
F744 F740 + 5.2V ± 0.2V
F712 + 4.1V ± 0.3V
F713 + 4.1V ± 0.3V
Functional check
picture DUT:
RF input
signal,
modulation =
50 kHz via
adaptation
network*
RF carrier
frequency
Input signal
Testpoints
grounded to F744
channel
switch
select
Output signal Voltmeter version
F748 863.3 MHz 1 mV rms F724 & F725 channel 1 F728 LF max output
for EUR and
UK version
F748 433.3 MHz 1 mV rms F724 & F725 channel 1 F728 LF max output
for some
EU countries
Alignment of the receiver EUR version
RF input
signal,
modulation =
50 kHz via
adaptation
network*
RF carrier
frequency
Input signal
Testpoints
grounded to F744
channel
switch
select
Alignment Align Output signal Voltmeter version
F748 863.3 MHz 1 mV rms F724 & F725 channel 1
FM Detector
coil
1710 F728 LF max output
for EUR and UK
version
Remove
groundings F724 &
F725
F748 863.3 MHz 250 µV rms channel 1
Sliding stereo
signal
3743 F747 >3 V DC
for EUR and UK
version
F748 863.3 MHz 250 µV rms channel 1
Sliding stereo
signal
reduce 3743
slowly
F747
between 0.2 and
3 V
for EUR and UK
version
F748 863.3 MHz 10 µV rms channel 1
Tuned/Muted
level
3741 F724 >2.5 V DC
for EUR and UK
version
F748 863.3 MHz 10 µV rms channel 1
Tuned/Muted
level
reduce 3741
slowly
F724 < 1 V
for EUR and UK
version
Alignment of the receiver for some EU countries
RF input
signal,
modulation =
50 kHz via
adaptation
network*
RF carrier
frequency
Input signal
Testpoints
grounded to F744
channel
switch
select
Alignment Align Output signal Voltmeter version
F748 433.3 MHz 1 mV rms F724 & F725 channel 1
FM Detector
coil
1710 F728 LF max output
for some EU
countries
Remove
groundings F724 &
F725
F748 433.3 MHz 250 µV rms channel 1
Sliding stereo
signal
3743 F747 >3 V DC
for some EU
countries
F748 433.3 MHz 250 µV rms channel 1
Sliding stereo
signal
reduce 3743
slowly
F747
between 0.2 and
3 V
for some EU
countries
F748 433.3 MHz 10 µV rms channel 1
Tuned/Muted
level
3741 F724 >2.5 V DC
for some EU
countries
F748 433.3 MHz 10 µV rms channel 1
Tuned/Muted
level
reduce 3741
slowly
F724 < 1 V
for some EU
countries
* e.g. SMT02
from Rohde &
Schwarz
DC Check
F701
F701
CL 36532008_148.eps
130503