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Emerson Radio
VIDEO I-F ALIGNMENT: (Table VI).
SIG N A I GENER
AT O R IN P U T
STEP
C O N N E C T IO N
FREQUENCY
1
Lightly couple
Sweep-23.5 MG.
marker gen. to
(10 MC. sweep)
pin 1 of V 3 ;
Marker-25.75
Sweep gen. from
pin 1 to chassis,
rhrough .001 mfd.
Connect marker
Sweep-23.5 MC.
2
and sweep gener
(10 MC. sweep)
ators to pin 1
Marker-25.25
of V 2, through
.001 mfd. Low
side to chassis.
Sweep - 23.5 MC.
Sweep generator
3
(10 MC. sweep)
coupled to con
Marker-25.75
verter (V 27) in
put, using three
turn loop slipped
over tube. Marker
gen. in parallel.
Low side to
chassis.
»
Sweep - 23.5 MC.
4
(10 M C. sweep)
9 9
5
Connect AGC
Sweep-23.5 MC.
bias battery as
(10 MC. sweep)
indicated above.
VIDEO I-F ALIGNMENT: (Table V I).
c.
T U N E R A L IG N M E N T :
1) Set fine tuning control to center of rotation.
Retain this setting or entire r-f alignment.
2) Retain control settings previously used.
3) Couple marker generator in parallel with sweep
generator.
4) Use 10 inc. sweep for sweep generator. Couple
generator to antenna terminals of receiver. If
the sweep has a 50 ohm, unbalanced output,
connect to the antenna terminals through net
work shown in figure 5-5.
5) Connect vertical input of scope in series with
10K resistor to junction of LI, R16, and C16.
6) Refer to figure 5-8 for tuner alignment points,
and figure 4-12 for the tuner schematic.
7) A14, A15, A l6 are r-f amplifier and converter
trimmers and are adjusted on Channel 12;
A13-A2 are oscillator slugs for the correspond
ing channels.
16
M E ASU R IN G
IN ST R U M E N T
Connect vertical
input of scope
through 10K re
sistor to junction
MC.
of LI, R16,
and C16. Low
side to chassis.
9 9
MC.
Connect scope
through detector
network to pin 1
of V 2. Low side
MC.
to chassis.
Connect scope
through detector
network to pin 1
Markers-
of V 3. Low side
22.8 and
to chassis.
21.25 MC.
Connect scope
through 10K re
sistor to junction
Marker s-
of L l, R16 and
25.75 MC.
C l 6. Low side to
and 22.25
chassis.
MC.
Scanned by mbear2k - Jan 20121/17
A D JU ST
PROCEDURE
T 4
Set marker as shown on
(Top and
response curve; marker
bottom)
should be 10% down. A d
just sweep generator in
put to produce one volt
at junction of L l, R16,
and C16.
Set 25.25 MC. marker as
T3
shown on response curve.
T1
Set marker as shown on
(L7 and
response curve.
L9)
Adjust primary of T2
T2
(top) to position 22.8
(Top and
MC. marker; adjust T2
bottom)
trap (bottom) to position
21.25 MC. marker.
Adjust T 2 (top) and T3
T2,
to give overall response
T3
shown. T2
(top) adjusts
bandwidth; T3 positions
video carrier (25.75 MC.)
depending on accuracy of
adjustment of T l
MC. marker).
OSCILLATOR AND CONVERTER 6J 6-
R-F AMP. OUTPUT TRIMMER A-14
CONVERTER TRIMMER A -l«
FINE TURIN©
CAPA6IT0R -
3-5 MM F .
OSCILLATOR ADJUSTMENT
A 2 - A 13
Figure 3-8— Tuner Alignment Points
RESPONSE
CURVES
25.75 MC.M ARK ER
/
BAND WIDTH
\
/
4.7
MC
I 25.25MC.
/T \
MARKER
/ \
J25.75MC. \
/■
MARKER
\
/
BANDWIDTH
\
L
___
______ ±
. ______
/J
22.80 MC.
l
/ n
MARKER
/
25.75Mclr
\1 2 2.25 MC.
/ )
\
m a r k e r
m a r k e r
/
BANDWIDTH
\
(25.75
/
3.5
M C
\
L*9
R-F AMPLIFIER
mo.y
6AG5
\
___
\
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