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AM-FM RF/IF AMP
MPX
ADJUSTMENT
AM ADJUSTMENT
For Alignment:
Maintain generator output as low as possible for suitable indication.
Adjusting
Sommecvon
Position of
V.T.V.M
Near max. capa-
Connect 455 kHz sweep
Connect oscilloscope
city of VC at
generator to VC 4.
to test point TP 4,
position of non
interference
Connect AM generator to
EXT AM ANT and GNO
terminals.
Set to 600 kHz. Modu-
AC. V.T.V.M
late with 30 %, 1 kHz.
output
Change frequency to
1400 kHz.
Mee ke
Repeat adjustments.
Connect oscilloscope and
. to Record
.
Variable capacitor completely closed
4.
Function switch to ""AM"
.
Set the dial pointer to very Jeft line dial scale.
5.
Use a screwdriver with plastic grip for all adjustment.
.
Connect sweep generator, SG,V.T.V.M. and oscilloscope.
1
2
3
FM ADJUSTMENT
FM IFT In
FRONT
END
Adjusting
Circuit
Position of
Tuning dial
V.T.V.M.
Oscilloscope
Output
Connect oscilloscope
to test point TP 2.
Connect sweep 10.7 MHz
Near max. capa-
generator to test point
city of VC.at
VC 2 through 0.01 UF.
position of non
Quadrature
Connect oscilloscope
Interference
FM QUADRA
Detector
to test point FP 1,
TURE
COIL
9-21320
Connect
FM RF generator
through two 120-ohm
resistors to FM ANT screw
terminals. Set generator to
90 MHz, modulate with
400 Hz to provide +75 kHz
deviation. Set generator out-
put
attenuator
as low as
possible.
Change generator setting
Connect V.T.V.M.
cs
ea
a
Repeat adjustments.
Connect V.T.V.M.
to Record output
1. Variable capacitor compeltely closed
4,
Function switch to "FM"
—
2.
Set the dial pointer to very left line of dial scale.
5.
Use a screwdriver with plastic grip for all adjustments.
3. Connect sweep generator, FM SG, V.T.V.M. and
oscilloscope. FM ANT input impedance is 300 ohm.
FM MPX ADJUSTMENT
Connection
Adjustment
PLLIC
Connect Frequency
Adjust VR Q1 (5k-B) so that
FO (19 kHz)
None
counter or synchro-
frequency counter or synchroscope
Adjustment
scope to TP 3.
indicate 19 kHz
As
above
Steps
3,4 except
Connect V.T.V.M.
to
Near max, Capa-
modulation
Modulate
LEFT
output terminal
city of VC. at
FM STEREO
channel +67.5 kHz — 400 Hz
(R channel}.
position of non
2
Signal
audio and +7.5 kHz — 19 kHz
interference
VR O2 (1k-B)
Separation
pilot carrier.
As
above
except
modulate
Connect V.T.V.M., to
RIGHT Channel.
output terminal
.
(L channel).
Repeat steps 1,2.
Set at position with max. channel separation.
Adjusting
circuit
Position of
tuning dial
1. Variable capacitor completely closed
3,
Function switch to "FM"
2. Connect FM stereo SG and V.T.V.M.
4,
Use a screwdriver with plastic grip for all adjustments,
—2-
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