Sony SPP-M100, Service Manual

Page: 19 / 35

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5-1. BASE UNIT SECTION
• Apply 9V dc from regulated DC power supply.
• Set to baseunit manual test mode. (Refer to page 11.)
• Switch position :
DIAL MODE : P (Pulse)
TX Section Adjustment
• Perform the adjustments at 25CH (46.970MHz) as a rule.
1. TX VCO Adjustment
Setting :
Procedure :
1
The digital voltmeter connected TP9 (TX VCO) to GND.
2
Adjust the L102 for 0.9 to 1.1V reading on the digital volt-
meter.
Adjustment Location : Base main board (see page 21)
2. RX VCO Adjustment
Setting :
Procedure :
1
The digital voltmeter connected TP8 (RX VCO) to GND.
2
Adjust the L2 for 0.9 to 1.1V reading on the digital voltme-
ter.
Adjustment Location : Base main board (see page 21)
3. SQ SENSITIVITY Adjustment
Setting :
Procedure :
1
FM rf signal generator condition :
Carrier frequency
: 48.970MHz
Modulation frequency : 1kHz
Deviation : 3kHz
Output level : –6dB
µ
V (0.501
µ
V) (EMF)
2
Adjust the RV601 so that the waveform appearing on the
oscilloscope has a duty of 50%.
(Since the waveform is not accurately observed, adjust so
that the top and bottom retrace lines are in the same condi-
tion.)
FM rf signal
generator
TP17 (ANT)
TP12 (GND)
TP10 (SQ)
oscilloscope
(DC range)
Procedure :
1
FM rf signal generator condition :
Carrier frequency
: 48.970MHz
Modulation frequency : 1kHz
Deviation : 3kHz
Output level : 60dB
µ
V (1mV) (EMF)
2
Adjust the L4 for the maximum reading on the level meter.
Adjustment Location : Base main board (see page 21)
2. IF Adjustment
Setting :
Procedure :
1
FM rf signal generator condition :
Carrier frequency
: 48.970MHz
Modulation frequency : 1kHz
Deviation : 3kHz
Output level : –6dB
µ
V (0.501
µ
V) (EMF)
2
Adjust the L3 for the noise level to minimum reading on
the level meter.
Adjustment Location : Base main board (see page 21)
RX Section Adjustment
• Perform the adjustment at T1CH (RX : 48.970MHz) as a rule.
1. DET Adjustment
Setting :
digital
voltmeter
TP9 (TX VCO)
digital
voltmeter
TP8 (RX VCO)
FM rf signal
generator
TP17 (ANT)
TP12 (GND)
TP402
TEL LINE
TP402
TP401
TP401
level meter
PBX tester
or
FB
DC48V
FM rf signal
generator
TP17 (ANT)
TP12 (GND)
TP29 (IF)
level meter
SECTION 5
ELECTRICAL ADJUSTMENTS