Marantz 2220 - Alignment and Adjustment Procedures; AM Alignment Procedures

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7. Test Equipment Required for Servicing
Table
1
lists
the
test
equipment
required
for
servicing
the
Model
2220
Reécewer.
Item
Manufacturer and Model No.
AM Signal Generator
Test Loop
FM Signal Generator
Stereo Modulator
Audio Oscillator
Oscilloscope
VTVM
Circuit Tester
AC Wattmeter
AC Ammeter
Line Voltmeter
Variable Autotransform-
er (0O-140VAC, 10 amps.)
Shorting Plug
Output Load
(8 ohms, 0.5%, 100W)
Output Load
(4 ohms, 0.5%, 100W)
8. AM Alignment Procedure
AM IF Alignment
1.
Connect
a
sweep
generator
to
the
J102
and
an
alignment
scope
to
the
resistor
R121(out
side)
.
2.
Rotate
each
core
of
IF
transformers
L102
and
L103
for
the
maximum
height
and
flat
top
symmetrical response.
Less than 0.3% distortion
Less than 0.3% distortion
Weston Model CVO-100P, less
than 0.02% residual distortion
is required.
High sensitivity with DC hori-
zontal and vertical amplifiers.
With AC, DC, RF range
Simpson, Model 390
Commercial Grade (1-10A)
Commercial Grade
(0-150VAC)
Powerstat, Model 116B
Use phono plug with 600
ohm across center pin and
shell. a
Commercial Grade
Commercial Grade
AM Frequency Range and Tracking Alignment
1.
Set
AM
signal
generator
to
525
KHz.
Turn
the
tuning
capacitor
fully
closed
(place
the
tuning
Signal source for AM align-
ment
Use with AM Signal generator
Signal source for FM align-
ment
Stereo Separation alignment
and trouble shooting
Sinewave and squarewave sig-
nal source.
Waveform analysis and Trou-
ble Shooting, and ASO align-
ment.
Voitage measurements.
Trouble Shooting
Monitors primary power to
Amplifier.
Monitors amplifier output un-
der short circuit condition.
Monitors potential of primary
power to amplifier
Adjusts level of primary pow-
er to amplifier.
Shorts amplifier input to eli-
minate noise pickup.
ae
Provides 8-ohm load for am-
plifier output termination.
Provides 4-ochm load for am-
plifier output termination.
pointer
at
the
low
end
)
and
adjust
the
oscillator
coil
L101
for
maximum
audio
output.
2.
Set
the
signal
generator
to
1650 KHz.
Place
the
tuning
pointer
in
the
high
frequency
end
and
adjust the trimming capacitor CA-2 for maximum audio output.