Marantz ST400 - Frequency Display Alignment Procedures

2. AM RF Alignment
Frequency Connection Pointer to:
525 kHz with L153 for maximum
tuning gang closed. output.
1,630 kHz with OSC. TRIM. CAP. for
VTVM
to
L
or
tuning
gang
open.
maximum
output,
R channel LO51 for maximum
525 kHz
Apply the signal to
the AM bar antenna 1,630 kHz
from the RF genera- oe
tor, using the test
600 kH 600 kHz
loop,
as
per
the
Figure
2
output
(W002)
output.
a
ANT.
TRIM.
CAP.
for
1,400 kHz 1,400 kHz inaximumioutputs
Repeat steps 1 to 4 as necessary to obtain maximum sensitivity.
Test
Loop
AM
Bar
Antenna
Figure 2. Application of AM Signal
4.5 Frequency Display Alignment Procedures
1.
FM Alignment
1) Confirm that a 22 k-ohm resistor of JO09 is connected to JQ04 side.
2)
Set
the
output
frequency
of
FM
signal
generator
at
98
MHz
accurately
by
using
the
frequency
counter,
and
connect
the
FM
signal
generator
to
the
FM
antenna
terminals
through
the
[HF
dummy.
3)
Set
the
Model
ST400
Tuner
in
normal
FM
reception,
and
tune
it
to
98
MHz
of
FM
signal
generator
output
by
observing
the
center
meter.
4)
Re-insert
JOO9
socket
in
the
opposite
position
of
step
1),
so
that
the
22
k-ohm
resistor
is
connected
to
JOQO3
side.
5)
Adjust
RQ04
semi-fixed
resistor,
located
on
right
side
in
front-view,
so
that
the
frequency
display
of
Model
ST4-00
is
stopped
the
switching
at
98
MHz.
6) Remove JQ08 socket as it is in step 1).
AM Alignment
1)
Set
the
output
frequency
of
AM
signal
generator
at
1000
kHz
accurately
by
using
the
frequency
counter,
and,
apply
the
signal
to the
AM
bar
antenna
from
the
RF generator,
using
the
test
loop, as
per
the
Figure
2.
2)
Set
the
Model
S$T400
Tuner
in
normal
AM
reception,
and
tune
it
to
1000
kHz
of
AM
signal
generator
output
byo
bserv-
ing
the
RF
signal quality
meter
for
maximum
deflection.
3) Insert JOO9 socket, so that the 22 k-ohm resistor of JQ09 is connected to JQ03 side.
4) Short-circuit the 22 k-ohm resistor for a few second by using the tweezers.
5)
Adjust
RQOS
semi-fixed
resistor,
located
on
left
side
in
front-view,
so
that
the
frequency
display
of
Model
ST4.00
is
stopped
the
switching at
1000
kHz.
6) Remove JQO8, and re-insert it so that the 22 k-ohm resistor is connected to JQ04 side.