Sharp QT-15XW Service Manual page 5

QT-15XW
GND GND
@ For adjustment in step 1, see | Note Bi.
TP2 TP5
TesT | FRE- [DIAL | AD-
STEP| BAND | STA- |QUEN- | SET- |JUST- Figure 5—1 FM IF
GE | cY |TING |MENT
IF (Connect instruments as shown in Figure 5—1.)
DUMMY (J101)
Figure 5—2 FM RF
Adjust for
maximum
output.
R1
To Telescopic Rod Antenna
2= 75 ohm << Rt" 37.5 ohm
88 88 L2
Track- | MHz MHz
ES 7
! R2 = 75 ohm
108 108 : R1 = 50 ohm
'&) ene <= R2 = 50 ohm
To Chassis GND
Repeat steps 2, 3, 4 and 5 until no further improvement
Z: Output impedance of signa! generator
can be made.
Figure 5-3 FM DUMMY
When ceramic filters other 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.
Color Mark
| Blue —|_: 10.67 MHz + 30 kHz
| Red | 10.70MHz+30kHz
1. Input
2. GND
3. Output
Central
frequency (fo)
Figure 5—4
NOTES ON SCHEMATIC DIAGRAM
1. Resistor: e The voltages in each part are measured with no signal given,
Unless otherwise specified, resistors are shown in ohm, by using a digital multimeter with the unit in play mode.
K (1000 ohm), and 1/4W type. The following must also be observed:
2. Capacitor: Radio circuit: Voltages without parentheses are for FM
e Unless otherwise specified, capacitors are shown in mode, and those with parentheses for
microfarads, P = Picofarads AM mode
e (CH), (RH) : Temperature compensation e Specifications or wiring diagram of this model are subject
to change for improvement without prior notice.