SONY SRFR405
Instrukcja Serwisowa

SECTION 3 ELECTRICAL ADJUSTMENTS
TUNER SECTION
[FM] Setting ENT/BAND switch : FM Signal generator
FM RF signal generator 16� 0.01µF Set Headphones jack (J401) TP1(ANT) MAIN board Level meter

0 dB = 1 µV

FM TRACKING ADJUSTMENT Adjust for a maximum reading on level meter. L202 76.0MHz CT202 108.0MHz AM VCO ADJUSTMENT Adjust so that the voltage at TP3(LPF) becomes 2.60 ±0.05V. L205 531kHz AM IF ADJUSTMENT Adjust for a maximum reading on level meter. T201 450kHz AM TRACKING ADJUSTMENT Adjust for a maximum reading on level meter. L201 CT201 585kHz 1,485kHz

22.5 kHz frequency deviation by 400 Hz signal 30% Output level : as low as possible

[AM] Setting ENT/BAND switch : AM
AM RF signal generator

FM STEREO (76kHz) ADJUSTMENT
Adjustment point Frequency Indication Frequency counter Reading

Put the lead-wire antenna close to the set. Set

Level meter 16�

RV301

FM76MHz

76kHz ±200Hz

FM STEREO (76kHz) Procedure :
FM RF SSG

30% amplitude modulation by 400 Hz signal Output level : as low as possible

Headphones jack (J401) Digital Volt meter

0.01µF to TP1(ANT) Carrier frequency : 76MHz Modulation : no modulation Output level : 0.1V (100dB)

MAIN board TP3(LPF)

1. Connect frequency counter to the positions shown below. 2. Tune the set to 76MHz.
TP4(76kHz) 0.01µF Frequency counter + � Use a frequency counter having input impedance of 10M� or higher.

� 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) �

TP4 (76kHz)

RV301 FM STEREO (76kHz) Adjustment

T201 AM IF Adjustment

L205 AM VCO Adjustment L201, CT201 AM Tracking Adjustment

TP3 (LPF) TP1 (ANT)

�4�

L202, CT202 FM Tracking Adjustment