Marantz 2325 - Test Equipment Required for Servicing; AM Alignment Procedures; AM IF Alignment

17. TEST EQUIPMENT REQUIRED FOR SERVICING
Table 1 lists the test equipment required for servicing the Model 2325 Stereophonic
Receiver.
Item Manufacturer and Model No. Use
AM Signal Generator
Signal source for AM align-
ment.
Test Loop
Used with AM Signal generator.
FM Signal Generator Less than 0.3% distortion
Signal source for FM align-
ment.
Stereo Modulator Less than 0.3% distortion
Stereo separation alignment and
troubleshooting.
Frequency Counter
MPX Oscillator adjustment
(VCO).
Audio Oscillator
Weston Model CVO-100P, less
than 0.02% residual distortion
is required.
Sinewave and squarewave signal
source.
Oscilloscope
High sensitivity with DC hori-
zontal and vertical amplifiers.
Waveform analysis and trouble
shooting and ASO alignment.
VTVM With AC, DC, RF range Voltage measurements.
Circuit Tester Trouble shooting.
AC Wattmeter Simpson, Model 380
Monitors primary power to Am-
plifier.
AC Ammeter Commercial Grade (1-10A)
Monitors amplifier output un-
der short circuit condition.
Line Voltmeter
Commercial Grade
(0-150V AC)
Monitors potential of primary
power to amplifier.
Variable Autotransformer
(0-140V AC, 10 amps)
Powerstat, Model 116B
Adjusts level of primary power
to amplifier.
Shorting Plug
Use phono plug with 600 ohm
across center pin and shell.
Shorts amplifier input to elimi-
nate noise pickup.
Output Load (8 ohms,
±1% 100W)
Commercial Grade
Provides 8-ohm load for ampli-
fier output termination.
Output Load (4 ohms,
±1% 100W)
Commercial Grade
Provides 4-ohm load for ampli-
fier output termination.
Table 1. Test Equipment Required for Servicing
18. AM ALIGNMENT PROCEDURES
18.1 AM IF ALIGNMENT
1. Connect a sweep generator to J153 and an alignment scope to the test point (B).
2. Turn each core of IF transformer L153 for maximum height and flat top
symmetrical response.
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5/30/2017
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