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Section
I
Model
339A
meter response
characteristics are
changed
to
those
of
a
volume
units
meter.
1-17.
OPTIONS.
1-18.
The
following options are
available for use
with
the
Model
339A:
Option
907:
Front
Handle
Kit
Option
908:
Rack Mounting
Kit
Option
909:
Front
Handle and Rack Mounting
Kit
Option
9
10:
Additional
Operating
and
Service
Manual
1-19.
Recommended
Test
Equipment
1-20.
Equipment
required
to
maintain
the
Model 339A
is
listed in
Table
1-3.
Other
equipment
may
be
substituted
if
it
meets
the
critical
requirements
listed in
the
table.
Table
1-1.
Specifications.
DISTORTION
Fundamental Frequency Range:
10 Hz
to
110 kHz
continuous frequency coverage
in
4
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1-
analyzer
and
oscillator
are
simultaneously tuned.
Distortion
Measurement
Range:
0.01
%
full
scale
to
1
00%
full
scale (-80
dB
to
0
dB)
in
9
Detection
and
Meter
Indication:
True
rms
detection
for
waveforms
with
crest factor
^
3.
Meter reads
dB and
%
THD
(Total
Harmonic
Distortion).
Meter response can be
changed
from
NORMAL
to
VU
ballistics
with
a
front
panel
switch.
Distortion
Measurement
Accuracy:
20
Hz
to
20 kHz
10
Hz
to
50 kHz
50 kHz
to
1
10 kHz
±1
dB
+1.
-2
dB
+
1.5.
-4
dB
The above
specifications
apply
for
harmonics
<
330
kHz.
Fundamental
Re/ection:
10
Hz
to
20 kHz
>100
dB
20 kHz
to
50 kHz
>
90 dB
50 kHz
to
1
10 kHz
>
86 dB
Distortion
Introduced
by Instrument
(
Input
>
1
V
rms)
10
Hz
to
20
kHz
20 kHz
to
30 kHz
30
kHz
to
50 kHz
50 kHz
to
1
10 kHz
<
-95
dB
<
-90
dB
<
-85
dB
<
-70
dB
Residual Noise
(Fundamental
frequency
setting
<
20
kHz,
80
kHz
filter in.
source
resistance
$
1
kCl
shielded):
<
-92
dB
referenced
to
1
V.
Input
Level
for
Distortion
Measurements:
30
mV
to
300 V rms
(100
mV
range
minimum)
Input
impedance:
100
kll
rl
.0% shunted
by<
100
pF input
High
to
Low
DC
Isolation:
Input
low
may
be connected
to
chassis
ground
or
floated
30
V
to
reduce
the
effects
of
ground
loops
on
the
measurement.
Auto
Set
Level:
No
set
level
adjustment
required.
Distortion
measurements
are
made
directly
over
10
dB range
selected by input
range
switch.
Two
LED
annunciators
provide
a fast visual
indication
to
change
input range
for
valid distortion
measurement.
Correct
range
isindicated
when
both
annunciators
are extinguished.
Auto
Null:
Using
internal
oscillators:
No
manual
frequency
tuning
necessary
when
using
internal
oscillator
as
signal
source
Oscillator
frequency
controls
simultaneously
tune
the analyzer.
Using external frequency source:
T
wo
LED
annunciators
provide
a
quick
visual indication for
the operator
to
in-
crease
or
decrease
the analyzer
frequency
controls.
When
the analyzer
is
rough tuned
to
within
one
least
significant
digit
of
the
fundamental
frequency,
the
in-
dicator
lights
are
extinguished
and
the
339A
auto-null
circuitry
takes over
to
provide
a
fast
accurate
null
without tedious operator
tuning.
input
Filters
(usable
on
all
functions):
Low
Pass
30
kHz
-
3
dB
point
at
30
kHz,
+2.6
kHz,
-
3 kHz.
Provides
band
limiting
required
by
FCC
for
proof-of-
performance
broadcast
testing.
80
kHz
-
3
dB
point
at
80
kHz,
+
7 kHz,
-
7.9 kHz.
Normally
used
with
fundamental
frequencies
<20
kHz
to
reduce
the
effect
of
higher frequency
noise
present
in
the
measured
signal.
High Pass
400
Hz -
3
dB
point
at
400
Hz,
+35
Hz,
-40
Hz.
Normally
used
with
fundamental
frequencies
>
1
kHz
to
reduce
the
effect
of
hum
components
in
the input
signal.
Monitor
Output:
Provides
scaled
presentation
of
input
signal
after
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