Revox A76 Service Manual

L402
Fig. 4.
16.-1
4Ja
Alignment of
38
kHz circuit
Test
equipment;
Test
generator,
frequency 94
MHz,
2
mV o.c.v.,
modulated
with
stereo-modulator,
75
kHz
deviation,
modulating
fre-
quency 1
kHz, left
channel only,
no
pilot
frequency.
Cathode- Ray
Oscilloscope
with
attenuator
10
:
1,
external
triggering
(
1 kHz
),
Y-amplifier, AC
sensitivity 0.02
V/cm
time base
50
jusec/cm
4.16.1.
Tuner:
power switch
depressed
set
dial
pointer to
94
MHz
mark;
fine tune
to
obtain
zero
indication
on the
CENTRE
TUNING
meter
(44).
4.16.2.
Connect
attenuator
to
test
point 1
0
(
see
fig. 4.
16.-1
)
4.16.3.
Tune
L501
of
the 38
kHz circuit
( fig. 4.
16.-1
)
to
obtain a
precise
envelope
crossover as
shown
in
fig.
4.
16.-2.
Fig.
4.1
7.-1
4.17.
Tuning
of
the 19
kHz band
pass
filter
Test
equipment:
Test
generator,
frequency 94
MHz,
2
mV
o.c.v.,
modulated
with
stereo-modulator,
75
kHz
deviation,
modulating
fre-
quency 1
kHz,
left channel
only,
pilot
carrier
9
%
(6.75
kHz
deviation)
Cathode- Ray
Oscilloscope
with
attenuator
10:1,
Internal
triggering,
Y-amplifier, AC
sensitivity 0.05
V/cm,
timebase
2
jusec/cm
4.17.1.
Tuner:
power
switch
depressed
Button
STEREO
AUTOMATIC
(
47
)
depressed,
set
dial
pointer
to
94
MHz
mark;
fine tune to
obtain
zero
indication
on CENTRE
TUNING
meter
(44).
4.17.2.
connect
attenuator
to test
point 1
1
(see
fig.
4.17.-1
).
4.17.3.
Adjust
19
kHz bandpass L401
and L402
( see
fig. 4.
17.-1
)
until
the
envelope crossover
coincides
with the
leading
edge
of the matrix
switching
frequency
(
see
fig. 4.
17.-2
).
Both
tuning
slugs
should
then be at approx,
the same height.
correct
incorrect
correct
incorrect
Fig. 4.
16.-2
Fig. 4.
17.-2
16

Revox A76 Specifications

General

Brand	Revox
Model	A76
Category	Tuner
Language	English