Table of Contents
Advertisement
6. FM/MW/LW Tuner Alignment Procedures
6-(1) FM Section
Descriminator, Center Meter, Distortion and Signal Gain
1. Press to FM position.
2. Connect an RF generator,
1 KHz modulation and 75 kHz
deviation,
to the antenna
terminals
on the rear panel
through a dummy antenna.
3. Connect
an Oscilloscope, Distortion
Meter and
VT VM
OSC
to the Rec. Out jacks on the rear panel.
c114 L103
L102
4. Tune to a frequency where there is no broadcasting.
(©)
(©)
5. Adjust a core indicated arrow (A) of T7131 so that the
:
YY
FM Tuning L.E.D. illuminates the center position.
:
6. Set the RF generator to 98 MHz.
1131
|
©©
OO
7. Set the dial pointer to 98 MHz.
R138
:
indi
8. Adjust a core indicated arrow
of T131
so that the
MUTING
TC5 tTc2 TC4 Tc1
;
fee?
nea
CENTER
(0)
ee
ANT
distortion is minimized at a value less than 0.4 %.
Tracking and Sensitivity
Precaution:
No adjustment is necessary. The tracking and
sensitivity
have
been
adjusted
properly
and
completely
at
the
factory.
If any
special
FREE
RUN
reason
occasioned,
take
the
following
pro-
cedures carefully.
1C102
Low Frequency
1IC103
1. Connect an RF generator the antenna terminals on the
O
rear panel through a dummy antenna.
109
2. Set an RF generator to 88 MHz, a modulation of 1 kHz
()
ee
and a deviation of 75 kHz to provide an input of 2 uV.
jacks on the rear panel.
4. Set the dial pointer to 88 MHz.
5. Adjust
the
three coils L103,
L102
and
L101
in the
tuning gang to maximize the output.
SEPARATION
High Frequency
6. Set the
RF
generator
to 108MHz,
a modulation
of
1kHz
and a deviation
of 75 kHz, to provide an input
of 2uV.
7. Set the dial pointer to 108 MHz.
8. Adjust the FM
trimmers
C114, TC2
and TC1
in the
tuning gang to maximize the output.
9. Repeat these high and low frequencies adjustment alter-
nately until maximum sensitivity is obtained.
Multiplex and Stereo Separation
Multiplex
Alignment Location on TFC-28F FM/AM Tuner
1. Set the Stereo
signal generator
as follows:
400 Hz
P.C. Board Assy
Fig. 8
modulation
frequency,
7.5kHz
deviation
pilot,
67.5 kHz main and sub carriers. Connect its output to
Frequency
Loop
.
an RF generator.
Counter
Antenna — AMSSG
Distortion Meter
92 Connect
an
RF generator to the antenna terminals
through a dummy antenna.
3. Connect
a VTVM,
an Oscilloscope
and
a Distortion
Meter to the Rec. Out jacks on the rear panel.
4. Set the RF generator to 98 MHz and output of 1 mV.
5. Set the dial pointer to 98 MHz.
6. Connect the Frequency Counter to 19 kHz Test Point.
(TP 109).
'
Hacewer
7. Switch off the pilot signal of Stereo Modulator.
FM 75 82: 75 2 PAD
8. Adjust R165 so that the frequency counter indicates
Fig. 9
19 kHz (O~-50 Hz).
R-S11L
SiG
No. 2517
Advertisement
Table of Contents
