Zenith Y504B - Page 18

18
WD
IF
ALIGNMENT
PROCEDURE
FOR
CHASSIS
26YT21
PURPOSE
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
necessarily
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
RF
output,
RF
input
and
FM
Antenna
stages
for
maximum.
Align
AM
IF
for
maximum.
Set
oscillator
to
dial
scale.
Align
detector
and
antenna
stages.
ADJUST
IRON
CORES
L15
kO
t -4
J
L13.L14
(N
4
r-4
r-H
J
o
T — <
4
a?
J
kD
4
tn
J
Readjust
L5,
L6,L9,L10, L11,L12,L13, L14
kJ
i-M
4
CM
4
co
U
00 ’ "■<
rH OJ
44
CN 04
44
CN r-M
C52E
C52D,C52C
SET
DIAL
TO
88
MHz
88
MHz
88
MHz
88
MHz
88
MHz
88
MHz
88
MHz
98
MHz
N
X
s
00
600
KHz
1600
KHz
1400
KHz
For
A,
B
z
C
See
Pages
13
and
14
INPUT
SIGNAL
FREQUENCY
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
10.7
MHz
400
KHz
Deviation
98
MHz
400
KHz
Deviation
98
MHz
400
KHz
Deviation
455
KHz
400
Cycle
Modulated
1600
KHz
400
Cycle
Modulated
1400
400
Cycle
Modulated
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
.05
in
series
with
hot
lead
of
gen.
LL
O'
CONNECT
GENERATOR
TO
Term.
#3
of
T4
4th
IF
Trans.
Term.
#3
of
T4
4th
IF
Trans.
1
erm.
#3
ot
T3
3rd
IF
Trans.
Test
Point
“
F
”
Term.
#3
of
T2
2nd
IF
Trans.
Test
Point
“
E
”
Connect
to
emitter
of
TR2
Mixer
Test
Point
#K
Connect
to
emitter
of
TR2
Mixer
Test
Point
#K
Connect
to
emitter
of
TR2
Mixer
Test
Point
#K
FM
Antenna
Post
(Remove
Antenna)
FM
Antenna
Post
(Remove
Antenna)
Base
of
TR8
Two
turn
loop
loose

ly
coupled
to
wave

magnet
Two
turn
loop
loose

ly
coupled
to
wave

magnet
OPERATION
— <
2
A
n
o
4
B
5
B
D
7
B
n
>0
<
□
o
r — 4
11
C
12
C