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(23)
(24)
(25)
(
26
)
(27)
(31)
(32)
Reset the
1
dB
STEP
ATTENUATOR
to
give
-8
dBm
on
the
9301 and
adjust
R134
until
the
UUT
meter
reads
-8
dBm.
Repeat operation
(21)
and
(22)
until
the
UUT
meter and 9301 agree
at
+3
dBm
and -8
dBm
levels
.
Recheck modulation
depth
and
distortion,
operations (16)
through
(19)
and
adjust
if
necessary.;
If
circuit has
been
adjusted, repeat operation
(20)
to
evaluate continued
suitability of
AOT
resistor
R161
.
Remove
the
9301
and reconnect
the
mod.
meter.
Check
that
audio
input
is
still
400
mV.
and
tune
UUT
to
520
MHz.
Ensure
that
at
+3
dBm
and
+2dBm
(use
VERNIER
to
control the
output
levels)
the
modulation depth
is
80%.
Reset
1
dB STEP
ATTENUATOR
and
VERNIER
control
to
give
maximum
output
(operation
15).
Remove
the
mod.
meter and connect
the
9301
.
Set
VERNIER
to
give
+3
dBm
on
the
9301
.
Select
X2
on
OUTPUT
LEVEL
switch
and
adjust
value
of
AOT
resistor
R159
so that the
9301
millivoltmeter reads
+9
dBm
±0.2
dB.
On
the
OUTPUT
LEVEL
switch solder
AOT
resistor
(33kQ
nominal)
across
R27
to
bring the
UUT
meter reading within ±0.1 dB
of the
9301 reading.
Operate
the
1
dB
STEP
ATTENUATOR
and
ensure
that steps of
1
dB
are
obtained on
the
UUT
meter.
Select
NORMAL
on
the
OUTPUT
LEVEL
switch
and
set
3
dBm
on
the
UUT
meter.
Reduce
level
using the
1
dB
STEP
ATTENUATOR
and check
that level
drops
In
1
dB
steps
.
Tune
UUT
to
1
.5
MHz,
select
X2
on
the
OUTPUT
LEVEL
switch
and
set level
to
±9 dBm.
Monitor LK1 on 19.0949
with the
AVO
on
+10
V
d.c. range
(positive lead
to link
and
negative
to chassis).
Adjust R19
to
obtain
a
reading
of
3.5
V
d.c.
Tune
the
UUT
from
1
.5
MHz
to
36
MHz
and
ensure
AVO
reading does
not
exceed 4 V.
Tune
the
UUT
over
the
remaining
ranges using the
60
kHz
CHANNEL
SPACING
selection
and
ensure
AVO
reading does
not
exceed
6
V.
NOTE:
It
may
be necessary
to
re-adjust
R19
slightly to
achieve low harmonic
distortion
and/or
minimum
spurious specification
on Band
1
.
However,
adjustment
of
R19 must
NOT
be
to
the
detriment
of the
output
level
specification.
9082C
Vol
.2
5-1
1(a)
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