Pilot
Ehase
Set
the
indication
Selector
(8106)
to
"L"
or
”R”
and
the
input
selector
(8101)
to
”on".
Apply
a
signal
to
the
L
and
R
channels
in
antiphase
at
f
=
500
Hz
and
with
about
—16
dBm.
Measure
at
the
multiplex
output
with
an
oscilloscope;
trigger
externally
with
pilot
from
Sthl.jb.
See
Figs
7b
and
7c
which
show
the
oscillograms
for
the
pure
pilot
tone
and
for
the
pilot
tone
with
difference
signal,
the
sensitivity
setting
being
the
same
for
both
pilot
tones.
The
voltage
VPH
referred
to
the
pilot
amplitude
V19
has
the
following
relationship
with
the
phase
angle
¢
in
degrees:
=
-——
x
—-—
(xp
in
degrees
with
respect
to
the
l9-kHz
pilot
frequency)
Set
the
pilot
mode
selector
(8107)
to
”on".
Measure
the
voltage
VPH'
Adjust
for
minimum
phase
with
R341.
VPH
<
3
mV
(2
<
0.20).
Set
the
pilot
mode
selector
(8107)
to
"AW3AU".
Measure
the
voltage
VPH'
Check
the
setting
range
available
when
using
R316
WAQ
".
VPH
should
be
varied
symmetrically
by
t8O
mV.
This
corresponds
to
a
phase
setting
range
of
approx-
imately
f5o
referred
to
the
above—mentioned
levels
(AF
voltage
~16
dEn,
pilot
level
-9.5
dEm).
If
the
Setting
range
is
extremely
asymmetrical,
vary
R315
so
that
VPH
<
10
mV
when
R316
is
at
its
mid—position.
Distortion
of
jB—kHz
subcarrier
Plug
links
E8101
and
BR102
into
T;
do
not
apply
an
AF
signal;
set
the
pilot
mode
selector
(8107)
to
”off”.
During
this
measurement
the
signals
-L
and
—R
are
replaced
by
DC
voltages
at
the
resistor
chain
(approx.
—4.3
V
at
test
point
MPlO4,
approx.
+4.3
V
at
test
point
MPlO8).
The
sequential
switching
follOWed
by
the
sampling
and
filtering
process
generates
a
38-kHz
voltage
with
a
sine—shaped
characteristic
in
the
ideal
case.
Any
errors
which
may
occur
in
the
resistor
network
or
the
switching
transistors
will
result
in
distortion.
Measure
the
distortion
at
the
multiplex
output:
k
g
0.5%.
R
58122
-
27
