Alignment Procedures - Harman Kardon 75+ Technical Manual

ALIGNMENT PROCEDURES
Step
1
2
3
4
5
6
7
8
9
10
11
12
13
FM IF & RF ALIGNMENT
INSTRUMENTS:
FM S.S.G., modulator with 400Hz at 100%, V.T.V.M., Oscilloscope, and Distortion Meter.
NOTE: Set TONE control to flat response (or mechanical center of both of BASS control and TREBLE control)
Set FUNCTION selector to FM.
SIGNAL SOURCE OUTPUT METER ADJUST ADJUST FOR
Check mechanical zero center of TUNING indicator, M101 at POWER switch OFF. Adjust it if necessary.
None (FM ANTENNA
TUNING indicator, Zero or center indication ON
terminals opened). Tuning connect osci 11 oscope
TOP adjuster of T101
TUNING indicator M101
control at no signal.
and V.T.V.M. to
(or RAT CAN) observing noise output with
TAPE OUT.
output meter._
Same as above. Same as above. Bottom adjuster of T101. Maximum noise output on
V.T.V.M.
Same as above. Same as above. TOP and bottom ad- Same as above.
justers of 'IF' in
FRONT-END
Connect SSG to FM ANT
terminal, with no signal Same as above. Readjust TOP adjuster Zero or center indication ON
(or SSG OFF). Tuning of T101. TUNING indicator, M101.
control at no signal.
Set SSG output to 88MHz, Same as above. LO, LR and LA in Maximum noise output on
Tune radio to 88MHz of FRONT-END. V.T.V.M.
SSG.
Set SSG output to 106M Hz, Same as above. TCO, TCR and TCA in Same as above.
and tune radio to 106MHz. FRONT-END.
Repeat step 6 and 7 for best sensitivity.
Use very weak signals of Same as above. LA and LR. Zero or center indication of
88MHz. TUNING indicator M101.
Tune radio to 88MHz.
Use very weak signals of Same as above. TCA and TOR. Same as above.
106MHz. Tune radio to
106MHz.
Repeat step 3 through 5 for best setting under SSG connected but no signal.
Use 98MHz, 1 mV signals Minimum harmonic distortion
from SSG modulated with Connect distortion Bottom adjuster of on distortion meter keeping
400Hz at 100%. Tune radio meter, V.T.V.M. and T101. noise output to 3V on
to 98MHz. (Note: If oscilloscope to
V.T.V.M. (adjust VOLUME
another signal exists, SPEAKER out.
CONTROL VR301 through
shift to quiet point) VR601, if necessary).
Observe output waveform with oscilloscope at S/N
=
20 to
30dB.
Observed waveform will be (1 ), (2) or (3), below:
(1)
1\;No,se , , ,
\
(3)
t
MODU-
LATING
FREQ.
400Hz.
Same as above. Same as above. UNACCEPTABLE UNACCEPTABLE ACCEPTABLE
Wave form (1) and (2) will result from misalignment.
(1) To correct, carefully adjust two adjusters of IF on the
FRONT-END and bottom adjuster of T101.
(2) Check TUNING meter zero center again under no signals
of SSG. If necessary, adjust the zero point with TOP
adjuster of T101.
(3) For ANTENNA input of 1mV from SSG, distortion shall
be adjusted with bottom adjuster of T101, if, necessary.
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