Electrical Adjustments - Sony SRF-HM03V Service Manual

0 dB=1 µV
[AM]
Setting:
BAND: AM
Put the lead-wire
AM RF signal
antenna close to
generator
the set.
30% amplitude
modulation by
400 Hz signal
Output level: as low as possible
[FM/TV/WEATHER]
Setting:
BAND: FM/TV/WEATHER
FM RF signal
generator
TP (ANT)
0.01 µ F
22.5 kHz frequency
deviation by 400 Hz
signal
Output level: as low as possible
MAIN board
TP (VT)
TP (GND)
• Repeat the procedures in each adjustment several times for a
maximum reading on level meter, and each tracking adjustments
should be finally done by the trimmer capacitors.
• Remove FM/TV/WEATHER lead-wire antenna in FM/TV/
WEATHER adjsutments.
Adjustment Location:
– MAIN BOARD (Conductor Side) –
CT1
TV (7-13CH)/WEATHER
TP
Tracking Adjustment
(ANT)
SECTION 3

ELECTRICAL ADJUSTMENTS

level meter
16 Ω
+
set
–
headphone
level meter
16 Ω
+
set
–
headphone
digital voltmeter
+
–
TP
(GND)
TP
(VT)
AM VCO VOLTAGE ADJUSTMENT
Adjustment Part Frequency Display Reading on Digital Voltmeter
L4 530 kHz
Confirmation 1710 kHz
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L3
CT3
FM/TV (2-6CH) VCO VOLTAGE ADJUSTMENT
Adjustment Part Frequency Display Reading on Digital Voltmeter
Confirmation TV 2ch (59.75 MHz)
Confirmation 108.0 MHz
FM/TV (2-6CH) TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L2
CT2
TV (7-13CH)/WEATHER VCO VOLTAGE ADJUSTMENT
Adjustment Part Frequency Display Reading on Digital Voltmeter
WEATHER 2ch
Confirmation
(162.4 MHz)
TV 13ch
Confirmation
(215.75 MHz)
TV (7-13CH)/WEATHER TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
CT1
L3
AM Tracking Adjustment
CT3
IC101
L4
AM VCO Voltage Adjustment
L2
FM/TV (2-6CH) Tracking Adjustment
CT2
SRF-HM03V
1.30 ± 0.05 V
8.10 ± 1.00 V
590 kHz
1490 kHz
1.95 ± 0.50 V
11.80 ± 1.00 V
TV 2ch (59.75 MHz)
108.0 MHz
3.10 ± 0.50 V
8.10 ± 1.00 V
TV 10ch (197.75 MHz)
7