HP 8340b User Manual

Accuracy
NOTE:
An
HP 8340B with
option
001
or
005
does
not have
a
step
attenuator.
Flatness
is
adjusted
and tested
with
the
RF
output
power
at
0
dBm
(RF
attenuator
at
0
dB
and
ALC
at
0
dBm).
The
frequency response
normally
remains
the
same
over
the
ALC
range.
For
accuracy
prob¬
lems
within
the
ALC
range,
refer
to
the
ALC
adjustments
in
Section
V,
Adjustments,
and to
the
RF
section functional
group
if
necessary.
If
accuracy
is
within
specifications
over
the
ALC
range,
and out of
specifications
below
the
ALC
range,
the
problems
is
probably
associated
with
the
RF
attenuator.
Note
that
the
RF
attenuator
is
outside
of
the
ALC
Loop.
The
instrument
processor
programs
the
RF
attenuator,
but
there
is
no
way
for
the
processor
to
know
if
the
attenuator
actually
stepped
properly.
If
the
power
level
is
off
by
a
factor
of
10
dB,
the
attenuator
may
not
be
responding
properly.
1.
Select
a
CW
frequency.
2.
Set
the
power
level
to
0
dBM.
3.
Press
[SHIFT] [PWR
SWP].
ATN:
-00
dB.
ALC:
0.00
dBm
appears
in
the
ENTRY
display.
4.
Using the
step
keys,
step
the
RF
attenuator
(and
RF
power
output)
to
—90
dB.
The
attenuator
should
click
at each
step,
and
the
RF
power
should
decrease
in
10
dB
steps.
If
the
attenuator
does not
perform
properly,
refer
to the
RF
section functional
group.
5.
There
is
an
offset
and
slope
calibration
constant correction factor
for each
RF
attenuator step
from
10
to
90
dB.
A
printed
copy
of
values
generated
at the
last
calibration
should
be located
inside
the
instrument
(see pocket
along
left
side
rail).
Check
the
calibration
constants
in
instru¬
ment
memory
against
the
printed
copy values
and
restore
the
correct
values,
if
necessary
(see
HOW TO RESTORE FACTORY
OPTIMIZED
CALIBRATION
CONSTANTS).
6.
If
the
attenuator
is
operating properly
and
the calibration
constants
are
correct,
check
the
RF
connections
from
the
A10
directional
coupler
to
the
RF
attenuator
and
measure
the
power
accuracy
at
the
attenuator
output.
SWEEP
(16)
1.
Make
sure
nothing
is
connected
to
the
rear
panel stop
sweep
connector.
NOTE:
Before performing
the following
steps,
use
the
SHIFT
M4
diagnostic test to
help
isolate
the
cause
of
a
sweep
problem.
For
sweep
problems,
refer
to
the
sweep
generator
—
YO
loop
functional
group
troubleshooting.
Use
the
following
information to
further
define
the
symptom.
The
following
steps
assume
the
instrument works
properly
in
CW
mode (no
UNLK
indication).
A-44
Assembly-Level
Service
Overall
Instrument
Troubleshooting
HP 8340B/41B

HP 8340b Specifications

General

Brand	HP
Model	8340b
Category	Inverter
Language	English