Marantz 2600 - AM Alignment Procedures; AM IF Alignment; AM Frequency Range and Tracking Alignment; FM Alignment Procedures

2. TEST EQUIPMENT REQUIRED FOR SERVICING
This table lists the test equipment required for servicing the Model 2600 Receiver.
Item
AM Signal Generator
Manufacturer and Mode! No.
Use
Signal source for AM alignment
Test Loop
Use with AM Signal Generator
FM Signal Generator
MPX Signal Generator
Sound Technology
Model 1000A
Signal source for FM alignment
Stereo separation alignment and trouble
shooting
Distortion Analyzer
Audio Oscillator
AC VTVM
Sound Technology
Mode! 1700A
Distortion measurements
Sinewave and squarewave signal source
Voltage measurements (AC)
Oscilloscope
Tektronix Model T932
Philips Model 3232
Waveform analysis and trouble shooting and
ASO alignment
Frequency Counter
Fluke Model 1900A
Circuit Tester
DC VTVM
MPX Oscillator adjustment (VCO)
Trouble shooting
Fluke Model 8000 ‘’Digital’’ Simpson
Model 313, Triplet Model 801
———
Voltage measurements (DC)
AC Wattmeter
Simpson Model 1379
Monitors primary power to amplifier
AC Ammeter
Commercial Grade (1-30A)
Monitors amplifier output under short circuit
condition
Line Voltmeter
Variable Autotransformer
Simpson Model 1359
Superior Electronic Co.,
Powerstat Model 116B—10A
Monitors potential of primary power to
amplifier
Adjusts level of primary power to amplifier
Shorting Plug
Use phono plug with 600-ohm
across center pin and shell
aren coe
Shorts amplifier input to eliminate noise
pickup
——_—|__
Output
Load
(8
ohms,
Commercial
Grade
+0.5%, 500 W)
Tt . ar une
Provides 8-ohm load for amplifier output
termination
3.
Output Load (4 ohms,
+0.5%, 600 W) Commercial Grade
AM ALIGNMENT PROCEDURES
3.1 AM IF ALIGNMENT
1.
2.
Connect a sweep generator to the J229 and an align-
ment scope to the test point B.
Rotate each core of IF transformers L153 and L154 for
maximum height and flat top symmetrical response.
3.2 AM FREQUENCY RANGE AND TRACKING ALIGNMENT
1.
Set AM signal generator to 515 kHz. Turn the tuning
capacitor fully closed (place the tuning pointer at the
low end) and adjust the oscillator coil L152 for maxi-
mum audio output.
. Set the signal generator to 1650 kHz. Place the tuning
Pointer in the high frequency end and adjust the oscilla-
tor trimmer on the oscillator tuning capacitor for maxi-
mum audio output.
Repeat steps 1 and 2 until no further adjustment is
necessary.
. Set the generator to 600 kHz and tune the receiver to
the same frequency and adjust a slug core of AM ferrite-
rod antenna LOO2 and RF coil £151 for maximum
output.
Provides 4-ohm load for amplifier output
termination
5. Set the generator to 1400 kHz and tune the receiver to
the same frequency and adjust both trimming capacitors
of antenna and RF tuned circuit for maximum output.
6. Repeat steps 4 and 5 until no further adjustment is nec-
essary.
NOTE: During tracking alignment reduce the signal gen-
erator output as necessary to avoid AGC action.
3.3 AM SIGNAL STRENGTH DISPLAY ADJUSTMENT
Set an AM signal generator to 1000 kHz at 100 dB/m, and
adjust R163 so that the spot may meet upper mark.
4. FM ALIGNMENT PROCEDURES
4.1 FM FREQUENCY RANGE AND TRACKING ALIGNMENT
1. Connect an FM signal generator to the FM ANTENNA
terminals and an oscilloscope and an audio distortion
analyzer to the TAPE MONITOR OUT jacks on the rear
panel.
2. Set the signal generator to 87.4 MHz and provide about
3 to 5yuV. Place the tuning pointer at the low frequency
end by rotating the tuning knob and adjust the core of