PICTURE IF TRANSFORMER TRAP ALIGNMENT
Test Equipment Connections:
Refer to Figure
GENERAL
. . . . . . . . . . . . . . . . Connect AC power plug through
isolation transformer to power supply.
BIAS SUPPLY . . . . . . . . . . . . Apply
volts bias to
OSCILLOSCOPE . . . . . . Connect to
through “IF TEST
BLOCK” shown in Figure Detector terminal B
is connected to
SWEEP GENERATOR . . . . . . . Connect
output in
series with “Out Put Pad” shown in Figure 5 to
MARKER GENERATOR. . . . . . Couple
loosely
to
Sweep
Generator Output Cable to provide markers.
. . . . . . . . . . . . . Used to check bias voltage.
Note: . . . . . . . Preset RF
control to mid-position. Set
Channel Selector to Channel
Alignment Procedure . . . . . . . . . See “General Alignment
before attempting alignment.
STEP
4
5
6
7
8
Recheck adjustment of
on tuner and
for correct response as shown in
of Figure
9
Reset RF
control
for normal operation.
ADJUSTMENT
GENERATOR
MARKER
GENERATOR
COMPONENT
PROCEDURE
Detector stage
3
(bottom core)
Adjust as shown on response curve “A” of
Figure
Adjust 3
attenuation of
Same as Step 1
Adjust
(Top core) alternately for
(Top
maximum attenuation of
as
transformer.
shown on response curve “A” of Figure
Recheck adjustment of
(Bottom core) for response as shown in “A” Figure
Remove the Sweep Generator lead from
and reconnect it to test point on tuner.
Remove the IF Test Block terminal A from the
and reconnect it to
of IF Test Block terminal
Apply
volts
bias to
Set channel selector to channel
Check
Adjacent channel
trap & sound trap
transformers
Same as Step 1
Adjust mixer col-
lector
in VHF
tuner
Same as Step 1
Adjust
transformer
Same as Step 1
Adjust for minimum dip at
MHz,
3
on
Adjust for maximum gain and the response
VHF Tuner
curve
in Figure
Same as Step 6
Remove the IF Test Block terminal B from the
and reconnect it to
of IF Test Block terminal A.
Apply
volts
bias to
Adjust for proper
curve
Same as Step 1
Same as Step
6
Align
and
for maximum gain and
obtain the response as shown in
Figure
Recheck adjustment
and for correct response as shown in
Figure
9
Summary of Contents for 8C221
Page 28: ...PRINTED WIRING BOARD ASSEMBLIES I Figure 18 PWB A Component Side 28 ...
Page 29: ...Figure 19 PWBA Wiring Side 29 ...
Page 30: ...Figure 20 FWB B Component Side 30 ...
Page 31: ...Figure 21 PWB B Wiring Side 31 ...
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Page 33: ...Figure 26 PWB E Component Side Figure 27 PWB E Wiring Side 33 ...
Page 34: ...Figure 28 PWM A Component Side Figure 29 PWM A Wiring Side 34 ...
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