Zenith Y504B - Page 15

RF
AND
IF
ALIGNMENT
PROCEDURE
FOR
CHASSIS
6YT01
PURPOSE
Align
IF
channel
for
maximum
output
Set
oscillator
to
dial
scale
Align
antenna
stage
Adjust
Primary
and
secondary
of
ratio
detector
for
maximum
amplitude
and
symmetry,
as
shown
in
Scope
Pattern
“
B
”
Align
I.F.
transformers
for
maximum
output
and
symmetry.
This
pattern
is
not
necessary
identical
to
the
overall
Scope
Pattern
“
A
”
Align
I.F.
transformers
for
maximum
output
and
symmetry
as
indicated
in
Scope
Pattern
“
A
”
Set
oscillator
to
Dial
Scale.
Align
FM
Detector
stage
for
maximum.
07,
T e s t
P o in t
“
H
”
.
te rm in al
#5
o f
T 2 0 5 ,
T e s t
P o in t
“
G 2
”
.
ADJUST
TF o
O T-l
CN 04
J U
CO
o o
04 04
CIO
ID
L103
Repeat
Procedures
#2
&
3
C101A
L212
L214
L208
&
L209
L205
&
L206
L201
&
L202
Readjust L201,L202, L205,L206, L208
&
L209
J
L2
SET
DIAL
TO
600
KHz
1600
KHz
600
KHz
1400
KHz
88
MHz
____________
88
MHz
88
MHz
88
MHz
88
MHz
88
MHz
98
MHz
98
MHz
BAND
BC
BC
BC
BC
S
FM
FM
2
FM
2
FM
INPUT
SIGNAL
FREQUENCY
455
KHz
400
Cycle
Modulated
1600
KHz
400
Cycle
Modulated
600
KHz
1500
KHz
400
Cycle
Modulated
10.7
MHz
400
KHz
Deviation
10.7
MHz
400
KHz
Deviation
10.7
MHz
400
KHz
Deviation
10.7
MHz
400
KHz
Deviation
10.7
MHz
400
KHz
Deviation
10.7
MHz
400
KHz
Deviation 98
MHz
400
KHz
Deviation
98
MHz
500
KHz
Deviation
DUMMY
ANTENNA
47
ohm
in
shunt
with
gen.
output.
Then
from
hot
lead
a
27
ohm
in
series
with
a
.001
MFD
capaci

tor.
300
ohm
300
ohm
CONNECT
OSCILLATOR
TO
One
turn
loosely
coupled
to
all
wavemagnet
Term.
#3
of
T205
3rd
IF
Trans.
Test
Point
“
Gl
”
Term.
#3
of
T203
2nd
IF
Trans.
Test
Point
“
F
”
Term.
#3
of
T201
1st
UF
Trans.
Test
Point
“
E
”
Connect
to
Test
Point
#D.
Junction
of
R6
1.8K,
R7
12K
&
C9
Feed
Thru
Condenser
on
FM
Tuner.
FM
Antenna
Post
(Remove
Antenna)
Test
Point
“
A
”
FM
Antenna
Post
(Remove
Antenna)
Test
Point
“
A
”
icro ss
V o ic e
C o il
scope
to
te rm in a l
#6
of
T 2
scope
w ith
diode
probe
to
OPERATION
1(A)
2(A)
4(A)
(v)s
6
B
7
B
8
C
9
C
10
C
1
11
C
U
04
r-4
13
C
(A )
V .T .V .W .
c
(B )
C o n n ect
o r
(C )
C onnect
or
15