HP 339A - Monitor Output and Oscillator Verification; AC Voltmeter and Distortion Analyzer Verification

Model
339A
Section
111
3-37.
Monitor
Output.
3-38.
The
MONITOR
output
provides
a
means
of
driving
external
equipment
to
permit a
more
detailed
analysis
of
the
signal
being
measured.
Instruments,
such
as
an
oscilloscope,
wave
analyzer,
or
spectrum
annalyzer
can
be
used
to
determine
the
nature
of
the
total
harmonic
distortion
being
measured.
The
monitor
output
level is 1
V
rms
for
full-scale
meter
deflection.
The
MONITOR
output
is
disabled
when
using
the
OSCillator
LEVEL
FUNCTION.
3-39.
OSCILLATOR
OPERATION.
3-40.
Frequency
Selection.
3-41
The
oscillator
frequency
is
determined
by
the
setting
of
the
FREQUENCY
and
FREQUENCY
VERNIER
controls.
The
units
and
tenths
controls
determine
the
first
and
second
digits
of
the
desired
r
'-r-
v, _
, o t-a thon
rrmltmheri
Hv thp
frequency,
inesc
nuiiiL/^ib
range
selected
on
the
multiplier
control.
As
an
exarriple:
to
set
the
oscillator
to a
frequency
of 5.6
kHz;
set
the
units
control
to
5,
the
tenths
control
to
.6,
and
the
multiplier
to
XI
K.
(The
FREQUENCY
VERNIER
should
be
set to
the
CAL
position.)
The
FREQUENCY
VERNIER
provides
continuous
frequency
tuning
between
steps
of
the
tenths
control
to
permit
continuous
frequency
selection
from
10 Hz
to 110
kHz.
3-42.
Output
Level.
3-43.
The
oscillator
output
level is
controlled by
the
OSCILLATOR
LEVEL
control
and
LEVEL
vernier.
The
OSCILLATOR
LEVEL
control
selects
output
levels
from 3
mV rms
full-scale
to 3
V rms
full-scale in
10 dB
V
steps (600
ohm
load).
The
level
vernier
varies
the
output
level
from
greater
than
3
V
rms
to less
than 1
m\
rms
(600
ohm
load).
3-44.
OPERATIONAL
VERIFICATION
CHECKS.
3-45. The
following
procedures
are
designed
to
test
the
operational
capabilities
of
the
Model
339A.
If
so
desired,
these
tests
can
be
substituted
for
the
performance
tests
outlined
in
Section
IV
for
incoming
inspection
tests
or to
check
operation
after
calibration.
Keep
in
mind
however,
these
tests
check
only
the
operational
capabilities
of
the
Models
339 A.
They do
no
t
check
the
performance
accuracy.
If the
instrument
fails
any
of
the
following
tests,
refer
service to
qualified
service
personnel.
3-46.
Preliminary
Procedure.
3-47.
Before
connecting
power to
the
339A,
perform
the
following:
a.
Be certain
that
the
rear
panel
VOLTAGE
SELECTOR switches
are
set to
correspond
to
the
available
power
line
voltage
and
that the
proper
fuse
is
installed.
b.
Connect
power
to
the
339A
and
turn
the
LINE
switch
ON.
c.
Set
the
FILTER
switches
off
(out).
d.
Set
the
METER
RESPONSE
switch
to
NOR-
MAL.
3-48.
OSCILLATOR.
3-49.
This
procedure
checks
the
output
level
of
the
339A
oscillator
for
all
frequency
settings.
Frequency
accuracy
is
not
checked.
To
check
the
oscillator
proceed
as
follows:
a.
Set
the
FUNCTION
switch
to
OSCillator
LEVEL.
b.
Set
the
INPUT
RANGE
control
to
the 10
volt
range.
c.
Set
the
FREQUENCY
controls
fully
counterclock-
wise.
d.
Set
the
OSCILLATOR
LEVEL
control
and
level
vernier
fully
clockwise.
The
meter
should
indicate
more
than
6
volts.
e.
Set
the
level
vernier
fully
counterclockwise.
The
meter
should
indicate
less
than 2
volts.
f.
Set
the
INPUT
RANGE
control
to
the
+10
dBm
range
and
adjust
the
level
vernier
for a
0
dBm
meter
indication
(blue
scale).
g.
While
observing
the
meter,
set
the
FREQUENCY
controls
to
each
dial
position.
(Allow
time
for
the
meter
reading
to
stabilize
at
each
setting.)
The
meter
indication
should
not
vary
more
than
0.6
dBm
from
the
original
setting.
h.
Set
the
FREQUENCY
controls
for
a
frequency
of
1
kHz.
i.
Adjust
the
level
vernier
for a
meter
indication
0
dBm.
j.
Simultaneously
down-range
the
OSCILLATOR
LEVEL
and
INPUT
RANGE
controls
to
the
next
lower
range.
The
meter
should
indicate
0
dBm.
k.
Repeat
Steps
i
and
j
for
each
position
of
the
OSCILLATOR
LEVEL
control.
3-50.
AC
VOLTMETER.
3-51.
The
following
procedure
checks
the ac
voltmeter
functions
and
ranges.
Perform
the
following
steps: