9.2
AM
Frequency
Range
and Tracking Alignment
1.
Set AM signal generator
to
525KHz.
Turn the tuning capacitor
fully
closed (place the
tuning pointer at the
low
end.)
and
adjust the oscillator coil L 152
for
maximum audio output.
2.
Set the signal generator
to
1650KHz.
Place
the tuning pointer in the high frequency
end
and adjust the oscillator
trimmer
on
the oscillator tuning capacitor
for
maximum audio
output.
3.
Repeat the step 1
and
2
until
no further adjustment
is
necessary.
4.
Set the generator
to
600KHz
and
tune the receiver
to
the
same
frequency
and
adjust a slug
core
of
AM ferrite rod antenna
and
RF
coil L
151
for
maximum output.
5.
Set the generator
to
1400KHz
and
tune the receiver
to
the
same
frequency
and
acijust both
trimming
capacitors
of
antenna
and
RF
tuned
circuit
for
maximum output.
6.
Repeat the step 4
and
5
until
no further adjustment
is
necessary.
Note: During tracking alignment reduce the signal generator
output
as
necessary
to
avoid AGC
action.
10. FM
ALIGNMENT
PROCEDURE
1.
Connect a FM signal generator
to
the FM
ANTENNA
terminals and a oscilloscope
and
an
audio distortion analyzer
to
the TAPE OUTPUT jacks on the rear panel.
2.
Set the
FM
SG
to
87.5MHz
and
provide about 3
to
5µV.
Place
the tuning pointer at the
low
frequency
end
by rotating the tuning knob
and
adjust the core
of
oscillator coil L 104
to
obtain maximum audio output.
3.
Set the FM
SG
to
108.5MHz
and
provide about 3
to
5µV output. Rotate the tuning knob
and place the tuning pointer at the high frequency
end
and
adjust the
trimming
capacitor
C106
for
maximum output.
4.
Repeat the step 2
and
3
until
no further adjustment
is
necessary.
5.
Set the FM
SG
to
90MHz
and
tune the receiver
to
the
same
frequency.
Decrease
signal
generator
output
until
the audio
output
level
decreases
with
the decreasing generator output.
Adjustthe
antenna coil L 101,
RF
coil
L102andL103
and
IF transformer L 105
for
minimum
audio distortion.
6.
Setthe
FM
SG
to
106MHz
and
tune the receiver
to
the
same
frequency.
Adjustthe
trimming
capacitor C102, C104
and
C105
for
minimum distortion.
7.
Adjust the secondary core(upper)of discriminator transformer L201
so
that
the center tuning
meter pointer indicates its center at no signal applied. Set the FM
SG
to
98MHz and increase
its
output
level
to
1
KµV
and tune the receiver
to
the
same
frequency
so
that
the center
tuning meter pointer indicates its center. Adjust the primary core (lower)
of
L201
for
minimum distortion.
10.1 Stereo Separation Alignment
1.
Set the
FM
SG
to
provide 1 Kµ V at 98M
Hz.
Tune the receiver
to
the
same
frequency
so
that
the center tuning meter pointer indicates its center.
2.
Modulate the FM
SG
with
stereo composite signal consisting
of
only
subchannel signal
(of
course a
pilot
signal must
be
included). Adjust the core
of
L301
for
maximum audio
output.
then, modulate the signal generator
with
a stereo composite signal consisting
of
only
L channel
signal and
again
adjust the core
of
L301
for
maximum audio output.
3.
Adjust the
trimming
resistor R365
for
maximum
and
same
separation in both channels.
10.2 Muting
Circuit
Alignment
1.
Connect a
VTVM
across
the resistor R487 and adjust the resistor R487
until
the meter
reads
0.
75V
DC
at no signal.
2.
Set the FM
SG
to
provide 1 KµV at 98MHz and tune the receiver
to
the
same
frequency
correctly.
7
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