Advertisement
The
use
of
a
Model 416A
in
a slotted
-
line system as
an SWR
indicator
offers
a
n advantag
e
i
n
a
ccurac
y.
By
sampling
the
output
from
the
signal
source, and us
i
ng the
vo ltage d
er
ived
therefrom
as a
refere
nce
voltage, the
Model 416A
eliminates
err
o
r
s
w
h
ic
h
with
a
no
ther type
of indicator would arise
when signal source
amp
li
tude
va:r
i
at
i
ons
o
cc
ur dur
i
ng measurement •
.
Q.f~
rating
Procedure
-
1.
Put the s igna
l source
into
operati
on
in
accordance
with the pro
c
e -
dures given in the
instructi
on book
for
the
type
of
signa
l
source
being
used.
Set
the
i
nst
rume
nt
to deliver a
signal of the desired
frequency
,
and
arrange
that th
e
signal
to
be delivered to the
slotted- line system
is
modulated
by
a
1
-
k
c
square-wave voltage.
2.
Assemble the
slotted-line system (Fi
g. 16
):
a
.
Connect
the
outpu
t
e
nd
of the
d irectional
coupler
to the slotted ·-
line.
section
(equipped with p
robe
and
detector).
b.
Connect
a
square-law d
e
t ecto
r
to the
s
e
condary
arm of the
coupler
.
c.
Connect a waveguide -to
-coaxial
adapter
to
the
input end of
the dire ctional
couple
r.
d.
Connect
the
adapter to the
s
ignal sourc
e.
(A
Hewlett
-
Packard
Type AC-16Q
c
oaxial
cable
is
suitable for
this connection.)
e.
Connect the
unknown load
to
the
output end of the slotted-line
section.
3.
On the Model 416A Ra tio Mete
r:
a.
Plug the
power
cable into
a
p
owe
r
line of specified voltage and
frequency.
Tu
r
n
the power
switch
to
ON.
Allow
t
he instru-
ment
about five
minutes to
r
each a state
of stable operation.
b.
With the
two BNC-to
-
BNC
cable
s
furni shed
with
the Model 416A,
make
the
fo llowing
co nnec
t
ions
:
(1)
With one
c
ab
le, connect
t
o the Model
416A
INCIDENT
I
REFERENCE
input
the
output of the
d etector on
the
seconda
ry
arm
of
th
e
di
rec
t
io
na
l
co
u
pler.
(2)
Connect the o
t
he
r cable
to
the
output of the slotted-line
probe
detector.
Thi
s cab
le
will
be used
later
to connect
the probe to
the Model 416A
REFLECTED/PROBE input,
but
this connection is not
to
b
e
made at
this time.
c.
Check that the
EXCESS COUPLER LOSS
switch is at the 0 DB
position.
-
41
-
..
Advertisement
