HP 3400A - Calibration Adjustments; 1 Volt Adjustment

Model
3400A
Maintenance
b.
Set
Model
3400A
RANGE
switch
to
0.1
volt
position
and
adjust
Voltmeter
Calibrator
for
0.01
volt
rms,
400
Hz
output.
NOTE
The
meter
may
show
a
small
positive
offset
when
the
3400A’s
in-
put
is
shorted.
This
is
normal
and
the
3400A
will
be
fully
accurate
from
1/10
scale
to
full
scale.
c.
Adjust
the
1/10
scale
adjust
(A6R626,
located
on
the
A6
assembly)
until
the
meter
of
the
3400A
reads
exactly
1/10
scale
(.01V).
Table 5-4. Power Supply Checks
Test
Equipment
Reguiation
Power
And
OC
Voltage
(Vary
Line
Voltage
Between
Ripple
Supply
Check
Point
Specifications
103.5
and
126.5
vac}
Specifications
-
17.5
Vde
Connect
Digital
-
16.8
to
18.2
Vde
+0.5
volt
from
nominal
|
400zV
rms
or
Multimeter,
Os-
reading
at
115
Vac
line.
1.1
mV
p-p
cilloscope
be-
tween
violet
lead
on
video
amplifier
(A4)
board
and
chassis
ground.
+75
Vde
Connect
Digital
70.0
to
78.0
Vde
+1
volt
from
nominal
|
400zV
rms
or
Multimeter,
Os-
reading
at
115
Vac
line.
1.1
mV
p-p
cilloscope be-
tween red/wht/
blue on video
amplifier A4 and
chassis ground.
5-25.
1
Volt
Adjustment.
Do
the
following:
a.
Connect
test
setup
illustrated
in
Figure
5-1;
omit
the
DC
Voltmeter.
b.
Set
Model
3400A
RANGE
switch
to
1
volt
position.
c.
Adjust
voltmeter
calibrator
for
1.0
volt
rms,
400
Hz
output.
d.
Remove
right
side
cover
(INPUT
side)
and
adjust
R104
(1
V
ADJUST)
for
Model
3400A
full-scale
meter
indication.
NOTE
The
adjustments
in
paragraph
5
~24
and
§—25
may
interact
with
each
other
and
may
have
to
be
readjusted,
after
performing
both
adjustments.
5-9