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9. AM Alignment Procedure
AM IF Alignment
1.
2.
AM Frequency Range and Tracking Alignment
1.
2.
6.
adjust the trimming capacitor C155-2 for maximum audio output.
core of AM ferrite rod antenna for maximum output.
.Set the generator to 1400 KHz and tune the receiver to the same frequency and adjust the
trimming capacitor C155-1 for maximum output.
Repeat the procedure 4 and 5 until no further adjustment is necessary.
Note:
During tracking alignment reduce the signal generator output as necessary to avoid AGC
action.
10. FM Alignment Procedure
1.
2.
Connect a FM signal generator to the FM antenna terminals and a oscilloscope and an audio
distortion analyzer to the tape output jack on the rear panel.
Set the FM SG to 87.5 MHz and provide about 3 to 5uV. Place the tuning pointer at the low
frequency end by rotating the tuning knob and adjust the core of oscillator coil L106 to
obtain maximum audio output.
. Set the FM SG to 108.5 MHz and provide about 3 to 5uV. Rotate the tuning knob and place
the' tuning pointer at the high frequency end and adjust the trimming capacitor C152 for
maximum output.
. Repeat the step 2 and 3 until no further adjustment is necessary.
.Set the FM SG to 90 MHz and tune the receiver to the same frequency.
Decrease signal
generator output until the audio output level decreases with the decreasing generator output.
Adjust the RF coil L104 and antenna coil L103 and IF transformer L105 for minimum audio.
distortion.
. Set the FM SG to 106 MHz 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 trimming capacitor C155-3 and C155-4 for minimum distortion.
. Repeat the step 5 and 6 until no further adjustment is necessary.
. Connect
a DC VTVM
with
1 V range selected across the capacitor C277 and adjust the
secondary
core
(black)
of discriminator
transformer
L201
so that no voltage reading
is
obtained on the VTVM
at no signal. Next set the FM SG to 98 MHz and increase the output
level 1 KuV, then tune the receiver to the same frequency so that no deflection is obtained on
the VTVM. Adjust primary core (pink) of L201 for minimum distortion.
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