Sharp GF-777H - Page 16

FM IF/RF ALIGNMENT
@
Set
the
wave-band
selector
switch
(SW1)
to
“FM”
position.
@
Set
the
FM
mode/FM
mute
switch
(SW108)
to
“stereo”
position.
(Refer to Figure 15-9)
>
— SIGNAL GENERATOR RECEIVER
STEP | BAND P ADJUSTMENT
STAGE CONNECTION TO | INPUT SIGNAL oak SEG BERRI
RECEIVER FREQUENCY
IF Refer to Figure 15-4. Exactly 10.7MHz. High end of dial. Adjust for best Adjust the FM
(Unmodulated) (minimum capacity) “S" curve. IF transformers
1 FM See 1. (T1)
Note B :
ote
2.
(T2)
Refer to Figure 15-5 Exactly 87.1MHz. Low end of dial. Adjust for | Adjust the FM
2 and 15-6. (400Hz, 30%, FM (maximum capacity) | maximum oscillation coils
ei Band modulated) output. (L4).
Coverage Same as step 2. Exactly 109MHz. High end of dial. Same as step 2. Adjust the FM
3 (400Hz, 30%, FM (minimum capacity) oscillation trimmer
modulated) (C19).
Same as step 2. Exactly 88MHz. 88MHz. Same as step 2. Adjust the FM
4 (400Hz, 30%, FM RF coils (L2, L3).
modulated)
FM Tracking
Same as step 2. Exactly 108MHz. 108MHz. Same as step 2. Adjust the FM
5 (400Hz, 30%, FM RF trimmer (C4).
modulated)
6 FM Repeat steps 2,3, 4 and 5 until no further improvement can be made.
| A ae ees EE
Color Mark
Color Mark
There are 5 kinds of ceramic filters (CF1, CF2) available
with this unit and they are given color indication as
tabulated below to differentiate the central frequency from
one to another among them. When using them, be sure to
make the two of the same type a pair.
When other ceramic filters than the one (red) having the
central frequency of 10.7 MHz are used, note that a marker
(10.7 MHz) of FM sweep generator, if used, will be deviated
— therefore, adjust the generator by putting off the
marker.
1. Input
2. GND
3. Output
10.64MHz +30kHz
| D | Black: |
Central
|
B
|
Blue:
|
10.67MHz+30kHz
frequency
|
A
|
Red:
—
[
10.70MHz
+30kHz
(fo)
10.73MHz
+30kHz
E | White: | 10.76MHz+30kHz
FM STEREO ALIGNMENT
@
Set
the
function
selector
switch
(SW102)
to
“radio”
position
and
FM
mode/FM
mute
switch
(SW108)
to
“‘stereo/mute”
position.
—
STEP
_—
SIGNAL GENERATOR
-
RECEIVER
ad
CONNECTION TO
RECEIVER
INPUT SIGNAL
FREQUENCY DIAL SETTING
REMARKS
ADJUSTMENT
Refer to Figures 15-6
and 15-7.
Exactly 98MHz (54dB) 98MHz
unmodulated. +0.1kHz.
Adjust for 19
ing semivar
variable res
Turn the FM muting sensitivity adjust-
iable resistor (R21) fully
counterclockwise. Adjust the semi-
istor (R27)
FM
STEREO
INDICATOR
LIGHTING
LEVEL
ALIGNMENT
©
Set
the
function
selector
switch
(SW102)
to
“radio”
position
and
FM
mode/FM
mute
switch
(SW108)
to
“stereo/mute”
position.
=F
SIGNAL
GENERATOR
RECEIVER
FM
EP
ND
7
ADJUSTMENT
SiLEr
BA
STAGE
CONNECTION
TO
|
iNPUT
SIGNAL
ser
TiNG
Scans
RECEIVER FREQUENCY
i
Refer
to
Figures
15-6
Exactly
98MHz
98MHz
Adjust
for
the
Adjust
the
semi-variable
Ss
and
15-8.
(20dB).
(19kHz,
indicator
starts
resistor
(R21).
:
id
eee
10%,
FM
lighting.
modulated)
—16=