Am-Fm Rf/If Amp/Mpx Adjustment; Am Adjustment; Fm Adjustment; Fm Mpx Adjustment - Sanyo DXT 5004 Service Manual

AM-FM
RF/IF AMP/M-PX ADJUSTMENT
1
.
Variable caoacitor
completelv
closed.
4'
Function switch to
"AM."
2.
Set
the
dial pointer to
very
left line dial
scale.
5.
Use a
screwdriver
with
plastic grip for all
adiustments.
3.
Connect sweep
generator,
SG,
V.T.V.M.
and oscilloscope.
AM
ADJUSTMENT
Step
Adjusting
c
ircu
it
Connection
SG.
frequencv
Position of
tuning
dial
Adiustment
V.T.V.M.
Oscilloscope
I
nput
Output
F
Connect sweep
gene-
rator
to
VC4.
Connect oscilloscope
to
rest
ooint
TP2
455
KHz
Near
max, capa-
city of
VC
at
position with
no
signal.
AM
'lst
9-21160
(Yellowl
AM
2nd
9-21170
(Whitel
AM
3rd 9-21180
455 KHz
z
RF
Connect standard
loop antenna to
output terminal
of
SG.
Place receiver 2 feet
from loop antenna
Connect
V.T.V,M.
to
TP2
600 KHz
(4OOHz.
3O %
modulation)
600
KHz
AM ANT
9-25030
AM
OSC
9-2081
0(Red)
Max.
1400 KHz
{400H2, 30
%
modulationl
1400 KHz
TC
AM
OSC
TC AM ANT
Max.
4 Repeat adiustments
FM
ADJUSTMENT
Step
Adjusting
circuit
Connection
SG.frequency
Position of
tuning
dial
Adiustment
V.T.V.M.
Oscilloscope
I
npul
Output
F
Connect sweep gene-
rator to
test
point
TP
5
through
0,01!F
Connect oscilloscope
to test ooint
TP3
10.7 MHz
(none modula-
tion
)
Near max.capa-
city of
VC.
at
position
with
no
si
gnal.
FM 1st9-21130
(Orange)
FM 2nd
9-21140
(Blackl
A
10.7MHz
2
Ratio Det,
Connect oscilloscope
to test Doint TP3
FM DET
9-20850(Pink
)
9-21150(Bluel
10.7MHz
3
RF
Connect FM SG. to
FM ANT terminals.
Connect
V.T.V.M.
to
speaker
terminal.
90 MHz
(4O0
Hz, 30
%
modulationl
90
MHz
FM
ANT
9.2112O
FM
OSC 9-20800
FM
Coil
9-20370
Max.
4
106 MHz
{400 Hz, 30
%
modulation)
106 MHz
TC
FM OSC
TC FM
CRF
Max.
5
Repeat adjustments.
1.
Variable capacitor
completely
closed.
2.
Set
the dial
pointer to
very
left
line
of
dial scale.
3.
Connect sweep
generator, FM
SG,
V.T.V.M.
and
oscilloscope. FM
ANT
input
impedance
is
3O0 ohm.
1-
Variable capacitor
completely
closed.
2.
Connect FM
stereo SG
and
V.T.V.M.
4.
Funcrion switch
to "FM AUTO".
5.
Use a
screwdriver
with
plastic grip for all
adiustments.
3.
Function switch
to "FM AUTO".
4.
Use a
screwdriver
with plastic
Arip
for
all adiustments.
-1-
FM MPX
ADJUSTMENT
Step
Adjusting
circu
it
Connection
Position
of
tuning dial
Adiustment
Inpul
Output
1
PLL
IC
FO (19
KHz)
Adiustment
None
Connect Frequency
counter or synchro-
scope
to
TP4
Near
max.
capa-
city of
VC. at
position with
no
signal.
Adjust
VR02
(5K-B)
so
that
19 KHz may be indicated on the
f
requency counter
or
synchroscope.
2
FM STEREO
Signal
Separation
Connect FMstereo SG
to
FM
ANT terminals. 19 KHz
signal
ON. Main channel, sub channel
signal ON.
Add
100O
Hz signal
from
L
Ch.
Connect
V.T.V.M.
to
output terminal
(R channel).
Connect FM stereo
SG
to
FM
ANT terminals. 19 KHz
signal
ON. Main channel, sub channel
signal
ON.
Add
10OO
Hz signal
from
R Ch.
Connect
V.T.V.M.
to
output terminal
(L
channell
3
Repeat
steps
2,
Set
at
position with
max. channel separation,
lJ