Am Tuned Level Adjustment; Fm Tuned Level Adjustment; Tuner Section - Sony HCD-H551 Service Manual

TUNER SECTION

Note: As a front-end (FE1) is difficult to repair if faulty, replace it
with new one.

AM Tuned Level Adjustment

Note: FM Tuned Level adjustment should be performed after this
AM Tuned Level Adjustment.
Setting:
Band: AM or MW
AM RF SSG
30% amplitude
modulation by
400Hz signal
Modulation: 999 kHz (at 9 kHz step)
1,050 kHz (at 10 kHz step)
Procedure:
1. Set the output of SSG so that the input level of the set becomes 55
dB.
2. Tune the set to 999 kHz or 1,050 kHz.
3. Adjust RV41 (EXCEPT Thailand model), RV42 (Thailand model)
to the point (moment) when the TUNED indicator will change
from going off to going on.
Adjustment Location: TCB board

FM Tuned Level Adjustment

Note: This adjustment should be after AM Tuned Level Adjustment.
Setting:
Band: FM
FM RF stereo signal
generator
75 coaxial
Carrier frequency: 98MHz
Modulation: AUDIO 1kHz, 75kHz
deviation (100%)
Output level: 25dB (at 75 open)
Procedure:
1. Supply a 25 dB 98 MHz signal from the ANTENNA terminal.
2. Tune the set to 98 MHz.
3. Adjust RV42 (EXCEPT Thailand model), RV41 (Thailand model)
to the point (moment) when the TUNED indicator will change
from going off to going on.
Adjustment Location: TCB board
0dB=1µV
loop antenna
60cm
Field strength dB (µV/m) = SSG output level dB (µV/m) –26dB.
set
FM ANTENNA terminal
(TM1)
loop antenna
(Supplied accessories)
AM antenna
terminal (TM1)
Adjustment Location:
EXCEPT Thailand model
[TCB BOARD] (Component Side)
RV42
RV42
FM Tuned Level
Adjustment
Thailand model
[TCB BOARD] (Component Side)
RV41
RV41
FM Tuned Level
Adjustment
— 14 —
set
RV41
RV41
AM Tuned Level
Adjustment
IC41
FE1
RV42
RV42
AM Tuned Level
Adjustment
IC2
FE1
TM1
TM1