Sharp RG-7550H Serviceanleitung Seite 6

TC901
1-905 L912
FM OSC
L903
1-907 1-911
L909
L910
SOI
T901
FM IFT
VRIOI
TIOI
T102
T103
T401
VR402
VR401
S02
VR501 VR502
(TOP)
(TEST POINT)
Figure 9 ALIGNMENT
TC902 T902
MW OSC LW/MW IFT
(BOTTOM)
POINT
GENERAL ALIGNMENT
Should it become necessaryat any time to check the alignment of this receiver, proceed asfollows:
I. Connect an output meter acrossthe 7 Pin DIN Socket (L-ch or R•ch out put).
2. Set the volume control at maximum.
3. Attenuate the signalsfrom the generator enough to swing the most sensitive rangeof the output meter.
4. Use a nonqnetallic alignment tool.
5. Repeat adjustments to insure good results.
LW/MW
Set the band selector switch at LW or MW position.
SIGNAL GENERATOR
TEST
STEP BAND
STAGE CONNECTION TO INPUT
RECEIVER FREQUENCY
Connect signal genera- Exactly 450kHz
(400Hz. 30%,
tor through a dummy
to the antenna socket. AM modulated)
MW
Ground lead to the
receiver Chassis.
(Refer to Figure 10.)
2 MW Repeat until no further improvement
Band
3 Cover-
age
Same as step I. Exactly 603k Hz
Track-
4 MW (400Hz, 30%,
tng
AM modulated)
5 Repeat stegx 3 and 4 until no further
MW
Band
6 LW Cover-
age
Same as step 1 Exactly
Track•
7 LW (400Hz.
AM modulated)
8
Repeat steps 6 and 7 until no further
1 5PF
z
INSTRUCTIONS
ALIGNMENT CHART
RECEIVER
ADJUSTMENT
SIGNAL
DISPLAY SETTING REMARKS
High end Of display Adjust for maxi- T902
(1602kHz)
mum output on
7 Pin DIN Socket.
can be made.
Low end of display Connect DC volt Adjust the MW oscillator
(531kHz) meter between MW coil L909
Vt terminal of
tuner and ground.
Adjust DC volt
meter 1.5V±O.2V.
High end of display Adjust DC volt Adjust the MW oscilator
(1602kHz) meter 8.0 V ±O.5V. trimmer
603k Hz
Same as step I . Adjust the MW RF Cod
1-907. 1-908.
improvement can be made.
Low end of display Same as Step 3.
Adjust the LW oscillator
; (155kHz) Adjust DC volt
coil L912.
meter 1.6V 0.2 V.
High end Of display Check DC volt
(281 kHz) meter 5.3V 20.5V.
164MHz Same as step I. Adjust the LW RF coil
164kHz
30%.
1-910. 1.91 1.
improvement can be made.
ro EXT. ANTENNA SOCKET.
R = 80.Z (ohm)
Z OUTPUT IMPEDANCE OF
SIGNAL GENERATOR
65
TO CHASSIS GROUND.
Figure 10 AM DUMMY
TC902.