Sony SRF-R405 - Section 3 Electrical Adjustments; Tuner Section

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SECTION 3
ELECTRICAL ADJUSTMENTS
[FM]
Setting
ENT/BAND switch : FM
Signal generator
[AM]
Setting
ENT/BAND switch : AM
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L202 76.0MHz
CT202 108.0MHz
TUNER SECTION
AM VCO ADJUSTMENT
Adjust so that the voltage at TP3(LPF) becomes 2.60 ±0.05V.
L205 531kHz
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L201 585kHz
CT201 1,485kHz
0 dB = 1 µV
• Repeat the procedures in each adjustment several times for a
maximum reading on level meter, and the frequency coverage
and tracking adjustments should be finally done by the trimmer
capacitors.
Adjustment Location :
– MAIN board (side A) –
– MAIN board (side B) –
TP3 (LPF)
TP1 (ANT)
TP4
(76kHz)
L202, CT202
FM Tracking Adjustment
L201, CT201
AM Tracking Adjustment
RV301
FM STEREO (76kHz)
Adjustment
L205
AM VCO Adjustment
T201
AM IF
Adjustment
22.5 kHz frequency
deviation by
400 Hz signal 30%
Output level : as low as possible
FM RF signal
generator
Set
0.01 µ F
TP1(ANT)
Level mete
r
Headphones jack
(J401)
MAIN board
16 Ω
AM RF signal
generator
Put the lead-wire
antenna close
to the set.
Set
Headphones jack
(J401)
MAIN board
TP3(LPF)
Digital
Volt meter
Level mete
r
16 Ω
30% amplitude
modulation by
400 Hz signal
Output level : as low as possible
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter.
T201 450kHz
FM STEREO (76kHz) ADJUSTMENT
Adjustment point Frequency Indication Frequency counter Reading
RV301 FM76MHz 76kHz ±200Hz
FM STEREO (76kHz)
Procedure :
1. Connect frequency counter to the positions shown below.
2. Tune the set to 76MHz.
0.01 µ F
FM RF SSG
to TP1(ANT)
Carrier frequency : 76MHz
Modulation : no modulation
Output level : 0.1V (100dB)
Frequency counter
0.01
µ F
+
–
TP4(76kHz)
Use a frequency counte
r
having input impedance
of 10M Ω or higher.