HP 8340b User Manual

UNLEVELED ANNUNCIATOR
(8)
NOTE:
After
performing
the
following
procedure,
use
the
SHIFT
M4
diagnostic
test
to
help
isolate
the
cause
of
an
UNLEVELED
condition.
The
UNLEVELED
light
indicates
the
status
of
RF
output
power.
If
the
UNLEVELED
light
is
off,
the
output
power
is
leveled;
if
the
light
is
on,
the
power
is
unleveled.
1.
Press
[SHIFT]
[PEAK].
This
may
solve
the
problem.
2.
Make
sure
that the
correct
leveling
mode
Is
selected:
Internal
leveling
=
I
NT
External
leveling
=
XTAL
Power
Meter
Leveling
=
METER
If
you are
using
an
external
millimeter-wave source module,
you must
press
[SHIFT]
[XTAL],
and
the
ENTRY
display
should
read:
EXT MODULE POWER:
XX.XX
dBm.
3.
Check
that the
power
level
requested
is
not
greater
than
the
maximum
power
specification at
the
given
frequency.
If
the
instrument
is
sweeping,
make
sure
that
the
power
requested
does not
exceed
the
maximum
power
specification
for
the
entire
band
or
bands
that
are
swept.
4.
If
the
output
power
is
unleveled
at
all
power
levels
and
all
frequencies,
suspect an
RF
section
problem
(A25
ALC
detector
or
the
A26
linear
modulator).
5.
If
the
power
levels at
some frequencies
and
not others
while the
instrument
sweeps,
the
SYTM
may
not
be
tracking
correctly.
Try
the
AUTO TRACKING
(press
[SHIFT]
[PEAK]).
6.
If
the
power
levels
at
some
CW
frequencies
and
not
at
others, press
[PEAK]
to
optimize
the
SYTM
tracking
at the
frequency
of
interest.
7.
If
the
power
is
unleveled
in
low
band
(10
MHz to
2.3
GHz)
only,
suspect
a
low band
ALC
or
RF
section
problem.
8.
If
the
power
is
unleveled
in
band
1
or
above
(2.3
GHz to
the
maximum
frequency),
suspect
a
high
band
ALC
or
RF
section
problem.
OVERMOD ANNUNCIATOR
(9)
You
can
cause
OVERMOD
if
you
use
FM
with
a
modulation
rate
that
is
too high.
The
other
known
causes
of
OVERMOD
are
internal
instrument
failures
in
the
AM,
pulse,
or frequency
modulation
circuitry (refer
to
A26
linear
modulator information
in
the
RF
section).
To determine
if
the
instrument
requires
service:
1.
Disconnect
any
cables
going
to
the
AM
or
FM
inputs.
2.
Press
[INSTR
PRESET].
If
the
OVERMOD
annunciator
comes
back
on,
the
instrument
requires
service.
HP
8340B/41B
Assembly-Level
Service Overall
Instrument
Troubleshooting
A-41

HP 8340b Specifications

General

Brand	HP
Model	8340b
Category	Inverter
Language	English