Fl Indicator Circuit; Frequency Display Circuit; Output Power Indicator Calibration - Pioneer SX-3800 Service Manual

8 . 4 F L I N D I C A T O R C I R C U I T
Frequency Display Circu it
o The counter IC (PD5009) has been designed to
match FM ceramic filter IF offset (caused by
displacement of the central frequency) by com-
bination of the inputs (of H or L level) applied
to pin nos.3 & 4. The matching IF offset in the
SX-3800 is determined according to the com-
binations of connections and disconnections
between the R 28 and R 28 resistors in the
equalizer assembly (AWM-22?). Check that the
combinations shown in the table below have
followed for the conesponding grades of FM
ceramic filters F1 - F3 (3 ranks - color coded).
If
the
SX-3800 frequency
display reads
97.95MH2 or 98.05MH2 when a 9B.00MHz
signal is applied to the receivet, adjust TCl so
that the display reads 98.00MH2 correctly.
If an accurate 9B.00MHz input signal source is
not available, tune the receiver to the nearest
known broadcasting station in the 98MHz re'
gion, and check that the station's frequency is
correctly displayed, adjusting TCl if necessary.
Output Power Indicator Calibration
1. Apply a l"kHz signal to the POWER AMP IN
terminals.
2. Adjusi the level of this input signal so that the
voltage on the output terminals (SPEAKERS)
read 8.95V (AC).
3. Adjust VR1(L) and VR2(R) so that the out-
put power indicator read L0 watts.
F L i n d i c a t o r a s s e m b l y
F i g . 8 - 5
I
I
I
F M c e r a m i c f i l t e r
{ F 1 - F 3 }
PD5009 AVtM-227
P i n n o . 3 P i n n o . 4
R 2 8 ( 2 . 2 n 1 8 2 9 ( 2 . 2 n )
R e d L
H C u t C o n n e c t
B l u e
H H
C u t Cut
O r a n g e
H
L C o n n e c t C u t
H = 5 . 5 V , L : O V
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