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Adjusting
circuit
AM-FM RF/IF MPX ADJUSTMENT
AM ADJUSTMENT
For alignment:
Maintain generator output as low as possible for suitable indication.
__
Connection
~—
Output
Connect sweep gene-
rator to VC 4.
Connect oscilloscope
to test point TP 19.
SG. frequency
455 kHz
Position of
tuning dial
Near max. capa-
city of VC at
position with no
signal.
Adjustment
AM 1st
9-21310
AM DET
9-21291
V.T.V.M.
Oscilloscope
455 kHz
Connect standard
loop antenna to
output terminal
of SG.
Place receiver 2 feet
from toop antenna.
Connect V.T.V.M.
to TP 19.
600 kHz (400 Hz
30% modulation}
600 kHz
MW OSC
9-20851
1400 kHz (400 Hz
30% modulation)
1400 kHz
TC 01
TC 04
150 kHz (400 Hz
30% modulation)
150 kHz
LW OSC
9-20860
350 kHz (400 Hz
30% modulation}
350 kHz
TC 02
TC 03
Repeat adj
ustments.
1. Variable capacitor completely closed
2. Set thed ial pointer to very left line of dial scale.
3. Connect sweep generator, SG, V.T.V.M. and oscilloscope.
FM ADJUSTMENT
Adjusting
Connection
circuit
Output
Connect oscilloscope
Connect sweep gene-
to test point TP 7.
rator to test point
TP 5 through 0.07 uF.
Connect oscilloscope
to test point TP 6.
Connect FM SG, to
FM ANT terminals.
Connect V.T.V.M.
to output terminal.
4. Function switch to "AM"
5. Use a screwdriver with plastic grip for all adjustments.
SG. frequency
10.7 MHz
(none modula-
tion)
90 MHz
(400 Hz, 30%
modulation)
106 MHz
(400 Hz, 30%
modulation)
Position of
tuning dial
Near max. capa-
city of VC. at
position with no
signal.
106 MHz
Adjustment
{FT In
FRONT END
FM DET
9-21320
TCA TCR
V.T.V.M.
Oscilloscope
Repeat adju
stments.
1, Variable capacitor completely closed
2. Set the di
al pointer to very left line of dial scale.
3. Connect sweep generator, FM SG, V.T.V.M. and
oscillasco
FM MPX ADJU
Adjusting
circuit
PLL IC
FO (19 kHz)
Adjustment
pe. FM ANT input impedance is 300 ohm.
STMENT
Connection
4.
Function switch to "FM"
5.
Use a screwdriver with plastic grip for all adjustments.
Output
Connect Frequency
counter or synchro-
scope to TP 8.
Position of
tuning dial
Adjustment
Adjust VRO1
(5k-B) so that
frequency counter or synchroscope
indicates 19 kHz.
FM STEREO
Signal
Separation
As above steps 3,4 except
modulation Modulate LEFT
Channel +67.5 kHz — 400 Hz
audio and +7.5 kHz — 19 kHz
pilot carrier.
As above except modulate
RIGHT Channel.
Connect V.T.V.M. to
output terminal
(R channel).
Connect V.T.V.M. to
output terminal
(L channel).
Near max. capa-
city of VC. at
position with no
signal.
VR 02 (1K-B)
Repeat steps 1,2. Set at position with max. channel separation.
1. Variable capacitor completely closed
2. Connect F M stereo SG and V.T.V.M.
3. Function switch to ''FM"
4. Use a screwdriver with plastic grip for all adjustments.
aay
FM IF CURVE
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——-»
IF FREQ.
FM IF
ALIGNMENT
ALIGNMENT
WAVE FORMS
WITH OSCILLOSCOPE TIME BASE SETTINGS
Vertical Sensitivity: 0.5V/em.
Horizontal Sweep: 100 usec./cm.
SQUARE WAVE
MPX F.R.F.C.
ADJUSTMENT
S- CURVE
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ims
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FM DETECTOR
ALIGNMENT
Vertical Sensitivity: 0.5V/cm.
Horizontal Sensitivity: 0.5V/em.
Vertical Sensitivity: 0.5V/cm.
Horizontal Sweep: 100 usec./em.
SINE WAVE
7
Vertical Sensitivity: 0.5V/cm.
Horizontal Sweep: 500 usec./em.
aeriess
AM IF CURVE
SYMMETRICAL
TUNING
Vertical Sensitivity: 0.5V/em,
i
r
Horizontal Sweep: 100 usec./em,
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AM IF
Peek.
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ALIGNMENT
_ AM-FM RF/IF MPX & LW MW
CONVERTER
BOARD LAYOUT
(TOP VIEW)
LW MW
ANTENNA
9251/10
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LWOSC,
LWANT. MWANT.
TCO4
9-20860.
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FM IF
9-21320
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FMT 611LU
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