HP 3400A Service Manual

Theory
of
Operation
Model
3400A
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Figure 4-1. Block Diagram
4-10.
The
dc
voltage
driving
meter
M1
is
also
available
at
the
DC
OUT
jack,
located
at
the
rear
of
the
Model
3400A.
:
4-11. DETAILED DESCRIPTION
4-12. input Attenuator Assembly At
4-13.
The
input
attenuator
assembly
is
a
capacitive-compensated
attenuator
which
provides
two
ranges
of
attenuation
for
the
12
positions
of
the
RANGE
switch.
See
input
attenuator
schematic
diagram
illustrated
on
Figure
6-1.
4-14.
When
the
RANGE
switch
is
positioned
to
one
of
the
six
most
sensitive
ranges
(.001
to
.3
VOLTS),
the
attenuator
output
voltage
is
equal
to
the
input
voltage.
When
the
RANGE
switch
is
positioned
to
one
of
six
highest
ranges
(1
to
300
VOLTS),
the
input
signal
is
at-
tenuated
60
dB
(1000:
1
voltage
division)
by
the
resistive
voltage
divider
consisting
of
R101,
R103,
and
R104.
Trimmer
C102
is
adjusted
at
100
kHz,
and
R104
is
adjusted
at
400
Hz
to
provide
constant
attenuation
over
the
input
frequency
range.
4-2

HP 3400A Specifications

General

Brand	HP
Model	3400A
Category	Measuring Instruments
Language	English