I/O Connectors (19; Remote Operation (20 - HP 8340B Manual

3.
Determine
the order of the spur (i.e. ratio of
YO frequency change to
spur frequency change).
If
the spur is
a
crossing spur, at
some
point the spur will be on top of the YO
frequency
and at
some
point (50
kHz away from the
YO
frequency) the spur amplitude
will
decrease.
If
the spur
is
a
crossing spur, refer to the
appropriate
spur family
type above.
4.
To determine which internal frequency source(s) is
generating the
spur:
a.
Change the
CW
frequency while monitoring the
SHIFT
-function diagnostics, looking for
a
sudden change
in
spur frequency and/or amplitude. For example, press
[SHIFT] [M1],
then
change
the
CW
frequency. Look
for
a
correlation between any sudden change
in spur fre¬
quency and/or amplitude with
a
change
in
M/N
output frequency or
20/30 output
frequency.
If
a
sudden change
in the spur occurs at the same time the
M/N
or
20/30
makes
a
large
change, the internal frequency source
that changed
is
probably one of the signals generating
the spur.
b.
If
you suspect
the
20/30, press [SHIFT] [M3]
to
display the PLL2 VCO frequency
and
PLL3
up
converter frequency and repeat the above test.
NOTE:
For more Information
on the diagnostic
modes, refer
to the Frequency
Range and
CW Mode
Accuracy test in Section
IV,
Performance Tests.
I
I/O CONNECTORS
(19)
To determine source or destination of input or output connector signals, and for troubleshooting
information, refer
to the front panel
—
rear panel functional group. Troubleshooting information
regarding 40
GHz
control signals
is
found under
the
paragraph
titled J18
-
8410B/C
Interface Connec¬
tor
in the
front panel
-
rear panel functional group.
REMOTE OPERATION
(20)
Section
IV,
Performance Tests, contains an
HP-IB Operation
Verification Program Listing. This
pro¬
gram verifies the
ability of the
instrument to respond to
a remote
input (complete HP-IB handshake).
The
program tests each data
bit and
reads the instrument status bytes.
If
the instrument exhibits
a
problem while running this test,
refer to the controller section functional
group.
If
you do not
see a
problem while running this program, and the instrument
does not respond properly
to other remote commands, refer to the computer documentation to read the computer HP-IB I/O card
status. By outputting the
I/O card status, the source
of the problem can be determined.
HP 8340B/41B
Change
7
Assembly-Level Service Overall Instrument Troubleshooting A-49