Zenith J584W - Page 15

RF AND IF ALIGNMENT PROCEDURE
CHASSIS 3WJR51 . 8WJR56,8WJR57
13
STEP
CONNECT
GENERATOR
TO
DUMMY
ANTENNA
CONNECT
VTVM/
SCOPE TO
INPUT
SIGNAL
FREQUENCY
SET
DIAL
TO
ADJUST
PURPOSE
NOTE:
For AM Alignment Use A Signal With 400 Hertz Modulation, Bandswitch In AM.
1
One turn loosely
coupled to
wavemagnet.
None
Speaker
Voice
Coil
455 KHz
600 KHz
L203, L204
(T202)
L207 (T204)
L210 (T206)
Align IF channel for maximum
output.
2
535KHz
Gang Closed
T101
Set Oscillator to dial scale.
3
1630KHZ
Gang Open
C1G
4
Repeat Steps No. 2 & 3 for minimum change.
5
1400 KHz |
1400 KHz 1
CID
Align Antenna stage.
NOTE:
For FM Alignment Use A Signal With 400 KHz Deviation, Bandswitch In FM. AFC “ Off".
6
Term. No. 5 of T205
3rd IF Trans.
Test Point “ G ”
47 ohm in
shunt with
gen. output.
Then from
hot lead
a 27 ohm
Scope-
Ratio ”
Detector
Test Point
“ H ”
10.7 MHz Gang
Closed
L212 (T207)
Adjust Primary and Secondary of
Ratio Detector for maximum ampli 
tude and symmetry as shown in Scope
7
L214 (T207)
Pattern “ A ” .
8
Base of Q2
Test Point "D"
in series
with a .001
MF
capacitor.
Scope
Last FM
IF Test
Point
L208 & L209
(T205)
Align I.F. transformer for maximum
output and symmetry. This pattern is
not necessarily identical to the over 
all Scope Pattern “ B ” .
9
“ G “
L205 & L206
(T203)
10
L201 & L202
(T201)
11
Readjust
L201, L202,
L205, L206,
L208, L209
Align I.E transformer for maximum
output and symmetry as indicated in
Scope Pattern “ B ” .
NOTE-
In Steps 10 and 11 Generator Ground MUST be Connected On Braid As Close To Gang As Possible.
12
FM Antenna Post
300 ohm
Scope
106 MHz 106 MHz
C13 Set Oscillator to dial scale.
13
(Disconnect
Last FM
IF
Test
90 MHZ
90 MHZ
L4
14
Antenna)
Test Point “ A ”
Repeat Steps 12 and 13 for minimum change.
15
Point
“ G “
106 MHz
106 MHZ
CIA
Align FM Detector stage for maximum.
16
90 MHz
90 MHz
L2 if necessary
17
106 MHz
106 MHz
C1H
Align FM Antenna stage for maximum.
18
90 MHz
90 MHz
LI if necessary
19
Repeat Steps 15 thru 18 for minimum change.
INOTE
■: The Following Applies Only To Chassis 8WJR56, 8WJR57, No Signal Input.
20
| None
| None
1 None
1 None
None
| R233
J Zero center tuning meter.
MULTIPLEX ALIGN
MENT PROCEDURE
Before Aligning or Servicing Multiplex Circuits Be Certain That RF, IF And Ratio Detector Are Correctly Aligned And That Operation Is
Normal On Monaural FM Signals. ............ , ................... - .
STEP
CONNECT
GENERATOR
TO
DUMMY
ANTENNA
CONNECT
SCOPE
AND/OR
ACVTVM
INPUT
SIGNAL
FREQUENCY
SET
DIAL
TO
ADJUST
PURPOSE
NOTE
: Place Bandswitch In FM STEREO Position.
1
FM Antenna Post
(Disconnect
300 ohm
Test Point
“ M ”
98 MHz
10% Pilot
98 MHz
T301
Adjust 19 kHz Amp for maximum.
Antenna)
Test Point “ A ”
NOTE: — Stereo Indicator Lamp may be on or off
during the above steps.
2
98 MHz
5% Pilot
R302
Adjust mute control to point where
stereo lamp lights up.
NOTE: — Stereo Indicator Lamp must remain on
during the following steps.
3
“ L ” Tape
Output
98 MHz
10% Pilot
L+R L — R
T203
Adjust for maximum L Channel
Reading
4
“ R ” Tape
Output
(Mod. L. Only
)
T302
if
necessary
Adjust for minimum R Channel
Reading
1 5
Repeat Steps 4 and 5 for minimum change.
To provide maximum separation.