Harmonic/Spurious
Outputs
T
oo
High
Harmonic
and
spurious
outputs
may
be
generated
by
A2
itself
or
may
be
present
in
either
the
300
MHz
INPUT
or
LO
INPUT
signals
.
There
is
a
direct
relationship
between
spurious
signals
on
the
1st
LO
and
spurious
signals
on
the
tracking
generator
output|if
the
1st
LO
moves
1
MHz,
the
tracking
generator
output
will
move
1
MHz.
There
is
a
ve-to-one
relationship
between
the
600
MHz
drive
spurious
outputs
and
tracking
generator
output
spurious
signals
because
of
the
pentupler
multiplication.
F
or
example
,
if
the
600
MHz
signal
moves
1
MHz,
the
tracking
generator
output
signal
moves
5
MHz.
If
the
harmonic
spurious
outputs
performance
test
has
failed:
1.
If
the
harmonic
spurious
outputs
performance
test
has
failed,
disconnect
the
tracking
generator
and
connect
a
spectrum
analyzer
,
such
as
an
HP
8566A/B
,
to
the
host
spectrum
analyzer's
1ST
LO
OUTPUT
.
2.
Set
the
host
spectrum
analyzer
frequency
as
indicated
in
the
performance
test,
with
SP
AN
set
to
0
Hz.
3.
At
each
frequency
setting,
press
4
TRIG
5
NNNNNNNNNNNNNNNNNNNN
SINGLE
.
4.
If
the
host
spectrum
analyzer
is
an
HP
8560A/E,
HP
8561B/E,
or
HP
8563A/E
press
4
CAL
5
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
MORE
1
OF
2
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
FREQ
DIAGNOSE
NNNNNNNNNNNNNNNNNNNNNNN
LO
FREQ
.
If
the
host
spectrum
analyzer
is
an
HP
8561A,
HP
8562A,
or
HP
8562B
,
press
4
RECALL
5
NNNNNNNNNNNNNN
MORE
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
FREQ
DIAGNOSE
NNNNNNNNNNNNNNNNNNNNNNN
LO
FREQ
.
5.
The
frequency
displayed
is
the
1ST
LO
OUTPUT
fundamental
frequency
.
Use
the
HP
8566A/B
to
measure
the
1st
LO
signal's
second
and
third
harmonics
levels
.
Note
The
1st
LO
typically
has
a
higher
harmonic
content
than
does
the
tracking
generator
output.
F
or
this
check,
the
variation
in
harmonic
content
versus
frequency
is
the
factor
of
interest.
6.
If
the
1st
LO
harmonic
level
variation
versus
frequency
tracks
the
tracking
generator
output
harmonic
level
variation,
replace
the
host
spectrum
analyzer
connection
to
the
LO
INPUT
on
the
tracking
generator
and
repeat
step
one
while
measuring
the
1st
LO
signal
at
A2J3
(temporarily
remove
A
T1).
7.
If
the
1st
LO
harmonic
level
variation
measured
at
A2J3
relative
to
the
1ST
LO
OUTPUT
is
slight
and
the
relative
harmonic
variation
tracks
the
tracking
generator's
output
harmonic
level,
suspect
the
host
spectrum
analyzer's
1ST
LO
OUTPUT
.
8.
If
the
1st
LO
harmonic
level
variation
versus
frequency
does
not
track
the
tracking
generator
output
harmonic
level
variation,
suspect
the
A2
assembly
.
If
sidebands
are
present
at
the
same
frequency
oset
at
every
output
frequency
,
check
the
spectral
purity
of
the
LO
INPUT
and
600
MHz
drive
signals
with
another
spectrum
analyzer
.
Set
the
host
spectrum
analyzer
to
zero
span
when
checking
the
1st
LO
.
Use
the
method
described
above
to
determine
the
1st
LO
frequency
.
A
1
MHz
sideband
on
the
1st
LO
appears
as
a
1
MHz
sideband
on
the
output
signal.
7-28
Service
Information
HP
85640A
RF
T
racking
Generator
Operation
and
Service
Manual
Содержание 85640A
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