Marantz 2275 - FM Alignment and Adjustments

6.
Set the generator to 600kHz and tune the receiver to the same frequency and adjust a slug
core of the AM ferrite rod antenna and RF coil L151 for maximum output.
Set the generator to 1400kHz and tune the receiver to the same frequency and adjust both
trimming capacitors of the antenna and RF sections of the tuning capacitor for maximum
output.
Repeat Step 4 and 5 until no further adjustment is necessary.
Note: During tracking alignment reduce the signal generator output as necessary to the lowest
warkable signal to avoid AGC action.
10.3 AM Signal Strength Meter Adjustment
Set the AM Signal generator to 1000kHz with 5KuV, and adjust R178 so that the signal
strength meter reads 80% of full scale deflection.
11,
1.
2,
os
FM ALIGNMENT PROCEDURES
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.
Set the generator to 87.0MHz and adjust its output to about 3 to 5yuV. Place the tuning
pointer at the low frequency end by rotating the tuning knob and adjust the core of oscillator
coi! L105 for muximum audio output.
Set the generator to 109.0MHz and provide about 3 to 5uV output. Rotate the tuning knob
and place the tuning pointer at the high frequency end and adjust the trimming capacitor
C106 for maximum output.
Repeat Steps 2 and 3 until no further adjustment is necessary.
Set the generator to 9OMHz and tune the receiver to the same frequency. Decrease the signal
generator output until the audio output level decreases with the decreasing generator output.
Adjust the antenna coil L101, RF coils L102, L103, and L104, and IF transformer L106 for
minimum audio distortion.
Set the generator to 106MHz and tune the receiver to the same frequency. Adjust the
trimming capacitors of antenna and RF tuning circuits for minimum distortion (C102, C103,
C104, C105).
Repeat Steps 5 and 6 until no further adjustment is necessary.
Adjust the secondary core (upper) of the discriminator transformer L201 until the center
tuning meter pointer indicates center on noise (no signal applied). Set the generator to
98MHz and increase its output level to 1KuV and tune the receiver to the same frequency so
that the center tuning meter pointer indicates center. Adjust the primary core (lower) of
L201 for minimum distortion.
Set the generator to 98MHz and increase its output to 100KuV. Adjust R374 so that the
signal strength meter reads 90% of full scale deflection.
. STEREO SEPARATION ALIGNMENT
Set the FM signal generator to provide 1KuV output at 98MHz. Tune the receiver to the same
frequency so that the center tuning meter pointer indicates center. Then turn off the
modulation of the generator, connect a frequency counter to the test point J310 (point ©)
and adjust R311 so that the frequency counter precisely reads 19kHz.
Modulate the generator with a stereo composite signal consisting of only L or R channel (of
course, the pilot signal must be included).
Adjust the trimming resistor R301 for maximum and same separation in both channels.
. MUTING CIRCUIT ALIGNMENT
Connect a VTVM to the center terminal of potentiometer with R363 and adjust R363 until
the meter reads 0.75V DC no RF input signal.