Sony LBT-A57CD - Page 76

AM SECTION
AM Tuning Level Adjustment
Setting :
BAND switch: AM or MW
Loop antenna B
Loop antenna A LI
~
}
‘AM RF signal
generator
set
Carrier frequency : 999kHz
30% amplitude
modulation by 400Hz signal
Procedure :
1, Set loop antenna A so that the loop antenna B input level
becomes 58dBy/m (0.8mV/m)
2. Tune the set to 999kHz.
3. Adjust the RV22 so that the TUNED indicator goes on.
Adjustment Location :
[TUNER BOARD] —Component Side-
Rv24
FM Tuning
Level Adjustment
Rv22
TP1 TULLE 9] M Tuning
Test point oj Level
FEI Adjustment
Rval
EM Stereo
a) Separation
Adjustment
Tai
FM NULL
Adjustment
Note on Ceramic Filter (CF1, 2, 3) Replacement
This set employs three ceramic filters (CF1, 2, 3) which should
have the same color marking to identify their center fre-
quency. Therefore FM IF offset adjustment by D609, D610
mounted is necessary to match the center frequency of the
ceramic filters used with FM intermediate frequency.
color marking
(CF1, 2, 3)
(CF3: G, IT model only)
©: Mounted
x : not Mounted
Ceramic filter Mount _ FM
intermediate
Color
|
Center
fre-
*A
*B
frequency
mark | quency (MHz) |} D610 D609 (MHz)
White 10.750 x e) 10.750
Red 10.700 (} ° 10.700
Black 10.650 {e) x 10.650
FM intermediate frequency is determined by the three types
as shown above. Ceramic filters of same center frequency, i.
e., of same color coding should be used for CF1, CF2 and CF3.
When replacing the ceramic filters, perform the FM Di-
scriminator Adjustment.
[Note on Inserting the Cord to the Connector on Tuner
Board]
© Insert the cord to the connector fitting Pin ® of the cord in
accordance with the white mark on the board at the con-
nector as shown in the figure.
|
cord
pin ®