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F
or
the calibration pro
ce
dur
e.,
i
t is n
eces
s
ar
y
that
the
ratio
m
e
ter
r
ec
eive
v
oltages of
the
s
ame arnp
H
tude
at
b
()
th
i
nputs.
Therefore
t
he
attenuator sho uld
be
se
t
t
o offer the
s
ame
a
mount
of
l
oss that
the amplifie
r
is rated to yie
l
d
i
n
gain.
g.
C
onnect the
amplifie
r-output
detec
tor
to the
M
ode
l
4
16A
RE
-
FLE
C
TED
/PRO
BE
input
.
With
the
a
mplif
ie
r
i
n operation, the
re
now wi
ll
be two voltag
e
s o
f
approxi
m
a
te
l
y the same amplitude at
the Mode
l
416A
i
nputs, a
v
o
ltage
fro
m
the
detector monitoring
the amplifier
input and
a
voltage from
the detecto
r
monitor
i
ng
the amplifier output
.
h. Set the
signal gener
ator
rf
fre quency
to the design
center fre-
quency of the
amplifier.
i .
Adjust the
Mode
l
4
16A S
ET
TO
FULL
S
C
ALE control
to obtain a
100% reading on
the
PERCE
N
T REFLE
C
T IO
N (REFLECTOMETER}
scale
.
This
procedure
calib
rate
s
the
rati
o
meter.
J•
With the attenuator and
the Model
4
1
6A SE
T
TO FULL
S
C
ALE con-
trol at the settings made during
calibration,
the circuit now is set
up to measure the
re
l
ative
fr equency
response
of the amplifier.
As the signal
frequency is varied,
the transfer
function
is meas -
ured.
Note, for
example,
that at
the 3
db points the ratio
will
be
down
1.
5 db on the mete
r.
T
his
is
because
the
meter is calibrated
to read th
e
square
root of the a
c
tua
l i
nput
vo
l
tag
e
ratio,
as stated
in the
Requireme
nts
paragr
aph
,
above.
-47
-
I-
_['
I-
I.
H
t:
(1
...
...
p
...
E
2
p
c
c
<
(
=
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