NAD 4130 - Adjustment Points; Oscillator Adjustment (OSC); IF Adjustment Procedure; Tracking Adjustment

7. Stereo separation
Set F M generator output to 1000 uV, modulate in mono only.
8. Adjust VR 4 for identical outputs in the two channels.
TOLERANCE +/— 20 mV.
9. Modulate FM generator left channel only and adjust VR 5 for minimum on right channel VT VM.
10. Modulate FM generator right channel only and adjust VR 5 for minimum on left channel VT VM.
11. If the minimum in step 9 and 10 are different, adjust VR 5 so that the readings are the same in both channels.
SPECIFICATION better than 40 dB separation.
12.
MPX
filter
Turn
off
audiomodulation,
leaving
pilot
tone
only.
Disable
|HF
filter
or
external
19
kHz
filter
if
used,
13.
Adjust
LPF
1
left
channel
and
LPF
2
right
channel
for
minimum
output.
SPECIFICATION
more
than
60
dB
suppression.
14.
Release
the
FM
NR
DEFEAT
switch
(out).
H
DYN
SEP
ADJUSTMENTS.
1.
Turn
VR
6
fully
clockwise.
2 FM NER separation effect.
Observe output from left channel with FM generator oe level 1000 xV and mdoulated 1 kHz left channel
only.
Reduce audiomodulation only from stereo generator so that left channel output is reduced by 6 dB (50%
stereo modulation).
The 19 kHz pilot signal MUST REMAIN modulated 8 — 10%.
3. Set FM generator output to 150uV and adjust VR 6 for —30 dB separation left to right channel. (or right to left).
TOLERANCE +/—2 dB
SYNTHESIZER FREQUENCY.
1. Tune to a known accurate frequency source, i.e. broadcasting station or synthesized / digital display FM
generator, preferably in the midband (95 — 100 MHz).
Connect DMM acros TP 2 (negative) and TP 1 (positive).
3. Adjust VC 2 so that DMM reads the same as recorded inE — 7.
TOLERANCE +/— 10 mV.
AM ALIGNMENTS
Unless repairs have been done to Oscillator Section, do not not adjust AM OSC coil or Trimming Capacitor.
If OSC Adjustment is needed, connect high impedance voltmeter (preferably DMM) between R35 and ground.
A. OSC ADJUSTMENT
1. Tune unit to show 1610KHz or 1602KHz on display and adjust VC3 to read 7.5V on DMM.
Tune unit to show 520KHz or 522KHz on display and adjust L3 to reads 1V £0.5V on DMM.
Repeat step 1 and 2 until no further improvement.
B IF ADJUSTMENT
1. For IF adjustment and Tracking adjustment connect VTVM to loudspeaker output (or tape output), only
one channel connection needed, and connect signal generator to antenna terminals. Adjust generator for 30%
modulation and approx. 100uV input.
Tune both generator and receiver to approx. 1000KHz, and adjust generator frequency for maximum reading
on VTVM. Then adjust IF T2, and IF T3 for maximum reading on meter.
C. TRACKING ADJUSTMENT
1. Tune unit and generator to show approx. 600KHz and adjust L2 to maximum reading on VTVM.
- 2. Tune unit and generator to show approx. 1400KHz and adjust VC1 (Trimming Capacitor) for maximum
reading on VTVM.
3. Repeat step 1 and 2 until no further improvement.
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ADJUSTMENT POINTS
AM_IF ADJ.
AM OSC ADJ.
MPX JER ADJ.
a
®
ie
ace
=
VR6 FOR
FM NR ADJ.
VR2,3,4.5.
FOR MPX ADJ.
VC2
AM TRACKING ADJ.
AM_OSC_ ADJ.
a RE lo.
L704 RF2.
L705 MIX.
IF ADJ.
0 IF.
707 OSC. 0
VR1 FOR
AUTO SEARCH ADJ.
FM DET ADJ.
REAR SIDE CORE
FM DET ADJ.
FRONT SIDE CORE.
FM DISTORTION ADJ.
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