Table of Contents
Advertisement
AUTO LOCK
The instructions so far have detailed
operation using
MANUAL
LOCK
.
This section
contains a description of
AUTO
LOCK,
its
advantages
and
disadvantages, and
ins
truc-
tions on
how
to use
it.
The HP
53445
can
phase
lock
the source
using
either
MANUAL
LOCK,
as
already
deser
ibed,
or
AUTO LOCK.
In both
modes,
the
desire
d lock frequency
is entered on
the HP
53445,
and lock
can occur
with
no manual
tuning.
AUTO
LOCK
requires
an
HP-IB
connection
from the HP
53445 to the
HP
8350B,
and cannot be
used in an automatic
system
when
an
external computer
is
used
as
a
controller.
The HP
8756A scalar
network analyzer is
also capable of
HP-IB
communication
with
the
HP 8350B over a
dedicated bus
called the 8756
System Interface.
This
connection allows
several
powerful
advantages
:
1.
HP
8756A CRT
will display
sweep
frequency information and sweeper
marker
frequencies
.
2
.
HP
8756A
INSTRUMENT
PRESET
will
preset both the HP 8756A and
the
HP
83508.
3. Save/Recall
function
on either
the
analyzer
or the
s weeper
wi
ll
save
or
recall
the
measurement
configura-
tion
of
both instruments.
4
.
The alternate sweep
function of the
8756A/
8350B will be enabled
.
The
HP
8350B
has
only
one
HP-IB
connector
.
It
can
go ei ther to the
HP 5344A
HP
-
IB connector
,
or
to
the
8756
System
Interface
,
but not to both
.
If the
8756
System Interface
is
used
,
then the sweeper
cannot
be controlled
by
the HP
53445
and
therefore AUTO LOCK
cannot
be
used
(see
figure
1).
I f
the
HP
5344A
HP
-
IB
is
connected
,
the
AUTO LOCK function
can
be
used
,
but the advantages of the 8756 System
Interface must be sacrificed (see
figure 6)
.
HP
8756A
Sc.Ilar
Network
Analyzer
HP 8350B
Sweep Oscillator
HP·IB
o
0
HP 53445 Microwave
Source
Synchronizer
SYS CONT Switch
to
"
1".
ADDRESS
Switche5
set to
Sweeper Address
Figure
6.
HP-IB
co
nnection
for
A
UTa
LOCK.
10
AUTO
LOCK
should only
be
used
when
the
convenience
of
locking
automatically
is
more important
than
the convenience added
by
the 8756 System
Interrace.
USI NG AUTO LOCK
In
all
modes
,
using
the system in
AUTO
LOCK
is very similar to using it in MANUAL
LOCK.
However
,
the
8756 System
Interface
cannot be used.
AUTO LOCK requires
an
SP-IB
connection from the
HP
53445
t
o
the sweeper
(see
figure
6)
.
Note that
the 8756 System
Interface
is
not
used.
The DIP switch
o
n
the
back
panel of
the
HP
5344A
must
be
set
properly
to
run
in
the AUTO LOCK
mode.
The
top
sw itch
must
be
set
to
the
SYS CONT
position.
This will be indicated
on
the
front
by a
"CONT" annunciator
on
the HP
5344A
.
The
bottom
five switches must
be set
to the
HP-IB
address
of
the
HP 8350B
.
(
This
address is factory
set
to 19,
but can be
checked and reset by
preSSing
[SH
I FT
],
[ LCL
]
on
the HP 8350B
.
)
The
bottom
switch
is the
least
significant bit.
See the HP
53445
Operating and Service Manual for details.
CW
,
CF
/
C>. F,
STRT/
STOP, modes
i
n AUTO
LOC
K
The
instructions for operation in
AUTO
LOCK are essentially the
same
as
those for
MANUAL LOCK
in all fo
u
r
HP
53445
modes
.
However,
in
AUTO LOCK,
the
HP
5344S can set up
the mode and the frequency of
the
HP
8350B
over
HP-IB
,
so it is not necessary
to
do
this
ma
n
ually
.
You will
need to
turn the
cw
filter
(
if any)
off,
and make
sure the
SWEEP
TRIGG ER mode is set to
inte
r
nal
(INT)
on
the
HP 8350B
.
In CW, be sure that the HP
8350B
s weep ti
me
is set to at least
100
ms.
In the
final
step,
the
[AUTO
LOCK] key
should be
activated
instead
of
the
[MANUAL
LOCK] key.
The
s weeper's
frequency
will
be
set
automatically
over
HP-IB
,
a nd the
8350B
mod
e
will
be
set
to
regular
CWo
For
single
frequency measurements (CW mode
on
the HP
53445), the 8350B mode must be set to
swept
CW
o
Do this
by preSSing
[SHIFT]
[CW].
LK/R mode in AUTO
LOCK
When using LK
/R
mode in AUTO LOCK, the HP
5344S sets the sweeper to STRT
/
STOP
mode
and
sets
the
start
frequency
to
the
lock
frequency
entered
on the
HP 5344A.
However
it does not set
the
stop frequency.
This
must be entered manually
on
the
sweeper
.
Also, do not forget to disable
the CW
filter
,
set
the sweeper
'
s sweep
time
to at
least 100 ms
,
and set the sweep trigger
to
external (EXT)
.
QUESTIONS/
ANSWERS
REGARDI NG
CONNECTORS
Q:
A:
I don
I
t have the programming connector
cable.
Can I use
the
system without
it?
This
connector
(HP
Part No
.
8120-3545)
is
used
to
trigger
the sweep
in
LK
/R
Advertisement
Table of Contents
