Sanyo PLUS T35 - FM Adjustments and Alignment Procedures; Instruments Used for Adjustments; FM IF Adjustment; FM Tracking Adjustment

INSTRUMENTS
USED
FOR
ADJUSTMENTS
This
set
is
specified
by
high
grade
of
standard,
especially
in
distortion
and
carrier
leak,
as
compared
with
the
conven-
tional
receivers.
Therefore,
the
instruments
used
for
various
adjustments
of
this
set
should
be
of
high
quality
and
high
grade,
and
always
serviced
and
adjusted
strictly.
FM
SG
Output,
more
than
50
dB;
high
grade
of
standard.
Strictly calibrated in phase; high grade
of standard conforming to the level
of FM SG.
20 Hz to 15 kHz, level within +0.1 dB,
low distortion (less than 0.01).
For automatic level; measurable up to
0.05%.
Distortion less than 0.02% (at 100 mV
to 1.5 V), S/N more than 80 dB.
19
kHz
band
pass
More
than
40
dB/oct,
38
kHz
attenua-
filter
tion
(more
than
60
dB).
Frequency
counter
Input
level
in
the
vicinity
of
76
kHz,
Stereo modulator
AF OSC
Distortion meter
\HF filter
(with
AMP)
possible
at
0.5
mV;
small
input
capa-
city
(cable),
less
than
50
pF;
high
input
impedance,
more
than
500K
ohms
(at
76
kHz);
displayable
up
to
76,000
kHz.
DVTVM Resolution less than 1 mV (DC).
(digital VTVM)
NOTE
e@
Use
high
quality
{HF
filter,
otherwise
the
center
“Q"
point
may
not
coincide
with
the
minimum
distortion
point
in
the
tuning
meter
center
‘’0"’
adjustment.
e \f the phase of the stereo modulator is calibrated by
means
of
ordinary
oscilloscope,
an
error
may
be
caused.
Hence,
the
phase
calibration
should
be
performed
strictly.
FM IF ADJUSTMENT
1.
V-curve
adjustment
(1)
Connect
TP-14
(hot)
and
TP-15
(aacthht
to
the
output
terminals
of
sweep
generator,
and
TP-3
(hot)
and
TP-6
(earth)
to
the
input
terminals.
(2)
Connect
300-ohm
balanced
type
resistance
IHF
filter
dummy
between
the
output
terminal
of
the
sweep
generator
and
the
set.
And
connect
100-kohm
IHF
filter
between
the
input
terminal
and
the
set.
-
(3)
Disconnect
ceramic
capacitor
C220
(0.022uF
).
(4)
Reduce
the
input
level
of
the
set
as
small
as
possible
so
that
the
output
waveform
may
not
be
saturated.
(5)
Adjust
T201
so
that
the
waveform
of
sweep
generator
attains
the
maximum
without
being
distorted.
FM TRACKING
FM-SG
TP-1(E)
TP-2(H)
NOTE
Match the center of V-curve with the center line of iis
ceramic filter being sued.
aed
a =?
2. S-curve
(1)
Connect
TP-14
(hot)
and
TP-15
(earth)
to
the
output
terminals
of
the
sweep
generator,
and
TP-7
(hot)
and
TP-6
(earth)
to
the
input
terminals.
|
NOTE
In
order
to
cut
the
direct
current
at
the
hot
side
of
the
sweep
generator,
connect
a
capacitor
(1uF/16V)
between
TP-7
and
input
terminal.
(2)
Turn
17202,
T203
until
the
waveform
of
sweep
generator
attains
the
maximum
without
being
distorted.
FM TRACKING
Set
FM
SG
as
follows:
modulation
frequency
1kHz,
fre-
quency
diviation
75kHz
DIV.
(100%
modulation).
Flip
the
MODE
switch
of
the
unit
to
“MONO”,
*
The
total
load
impedance
of
the
testers
connected
to
the
unit
at
the
TP12,
13
and
ground
should
be
100K
ohms.
(1)
Make
LOW
TRACKING
adjustment
by
means
of
L102,
L103
and
L104.
Use
90OMHz
FM
signal
for
this
purpose.
(2)
Make
HIGH
TRACKING
adjustment
by
means
of
CT3,
CT2
and
CT1.
Use
1O6MHz
FM
signal
for
this
purpose.
(3)
Make
complete
TRACKING
adjustment
by
repeating
steps
(1)
and
(2).
*
When
properly
adjusted,
the
distortion
factor
of
the
output
from
the
unit
is
reduced
to
aminimum,
provided
that
the
distortion
factor
of
the
SG
output
is
about
3%.
TP-1H{E)
TP-12, TP-AHH)