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RADIO ALIGNMENT INSTRUCTIONS
19
20
21
19
20
22
23
24
25
26
ALIGNMENT INSTRUCTIONS— READ CAREFULLY BEFORE ATTEMPTING ALIGNMENT
When complete receiver alignment Is to be performed align the FM IF Amp. before aligning AM IF Amps.
To set pointer turn tuning cap fully closed and set pointer to last reference mark at low frequency end of dial.
Volume control should be at maximum position. Output of signal generator should be no higher than necessary to
obtain an output reading.
Use an Insulated alignment screwdriver for adjusting.
FM IF ALIGNMENT USING AM SIGNAL GENERATOR AND VTVM
Connect two matched 100K2 (t 1%) resistors In series from Polntdj^to chassis.
The Junction of these two resistors
Is alignment Point<g>as shown on the schematic.
'
DUMMY
ANTENNA
.01MFD
.Q1MFD
.01MFD
SIGNAL
GENERATOR
COUPLING
High side to pin 1
(Grid) Of 6AU6 (V23).
Low side to chassis.
Across antenna ter-
minals.
SIGNAL
GENERATOR
FREQUENCY
10.7MC
(Unmod. )
10.7M3
BAND
SWITCH
POS.
FM
(Ext.
clock-
wise.)
RADIO
DIAL
SETTING
Tuning gang
fully closed
ii
CONNECT
VTVM
DO Probe to
Polnt<£X Com-
mon to chas-
sis.
DC Probe to
Point ^J> Com-
mon to Point
f>
DC Probe to
Point^ Com-
mon to chas-
sis.
ADJUST
A36
A37
A38,
A39,
A40,
A41
REMARKS
Adjust for maximum deflection.
Adjust for zero reading.
A posi-
tive and negative reading will be
obtained on either side of the
correct setting. Repeat steps 19
and 20 If A37 required much ad-
justment.
Adjust for maximum deflection.
Alternately load the primary and
secondary windings of the IF
transformers with 680ffl while the
opposite side of the same trans-
former is being adjusted.
•Use frequency modulated signal with 60^, modulation and 450KO sweep.
Use 120% sawtooth voltage In scope for
horizontal deflection.
DUMMY
ANTENNA
.01MFD
.01MFD
DUMMY
ANTENNA
Two 1202
carbon
res.
SIGNAL
GENERATOR
COUPLING
Across antenna ter-
minals .
SIGNAL
GENERATOR
COUPLING
Across antenna ter-
minals with 120S
resistor
in each
lead.
SIGNAL
GENERATOR
FREQUENCY
10.7MC
(450KC
Sweep )
SIGNAL
GENERATOR
FREQUENCY
106MC
90MC
BAND
SWITCH
POS.
FM
BAND
SWITCH
POS.
FM
RADIO
DIAL
SETTING
Tuning gang
fully closed
;
M RF ALIGNMEU
RADIO
DIAL
SETTING
106MC
(5 3/4" to
right of
left hand
calibration
mark at low
freq. end of
dial back
plate).
9 CMC
(1 1/8" to
right of
the
reference
point listed
above) .
CONNECT
SCOPE
Vert. Amp. to
Point\/>. Low
side to chas-
sis.
Vert. AmP- to
Point^p Low
side to chas-
sis.
CONNECT
VTVM
DC Probe to
Point ^pi Com-
mon to chas-
sis .
ADJUST
A36,
ASS,
A39,
A40,
A41
A37
ADJUST
A42,
A43
A44,
A45
REMARKS
Disconnect stabilizer C7. Adjust
for maximum amplitude and symmetry
as per Fig 5.
Reconnect stabilizer cap C7. Adjust
A37 so crossover point occurs at
center of pattern as per Fig 6.
Slightly retouch A36 for maximum
amplitude and stralghtness of
crossover lines. Continue with
step 22.
REMARKS
Adjust for maximum deflection.
ii
FM IF alignment must be complete before starting AM alignment.
Volume control should be at majcimum position. Output of signal generator should be no higher than necessary to
obtain an output reading. Use an insulated alignment screwdriver for adjusting.
DUMMY
ANTENNA
.01MFD
200MMFD
200MMFD
SIGNAL
GENERATOR
COUPLING
High side to pin 7
(Grid) of 6BE6 (V21).
Low side to chassis.
High side to terminal
2 of antenna terminal
strip. Low side to
chassis.
SIGNAL
GENERATOR
FREQUENCY
4S5KC
(40CA,
Mod.)
1400KC
600KC
BAND
SWITCH
POS.
AM
(3 pos-
itions
clock-
wise)
RADIO
DIAL
SETTING
Tuning gang
fully closed
1400KC
(5 15/16" to
the right of
left hand
calibration
mark at low
freq. end of
dial back
plate).
600KO
(1 1/4" to
the right of
the
reference
point listed
above.
OUTPUT
METER
Across voice
coil
ADJUST
A46,
A47,
A48,
A49
A50,
A51
A52,
ASS
REMARKS
Adjust for maximum output. Alter-
nately load the primary and secon-
dary windings of the AM IF trans-
formers with 47KS2 while the oppo-
site side of the same transformer
is being aligned.
Adjust for maximum output.
Adjust for maximum output. Repeat
steps 24 and 25.
FIG.5
FIG. 6
PAGE 8
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