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40.
FREQUENCY
RESPONSE CHECK.
a.
Using
a
10
Mc to
12.4
Gc signal
source
and
an
SWR
Meter as the
indicator,
connect
the
Detector
to
the
signal source
and
set any
convenient
upper
scale
reference
on
the
SWR
meter.
b.
Withoutchanging
the RF
output
level
of
the
SWR
meter settings,
disconnect the
Detector from
the
sig-
nal
source.
c.
Using
a
power
meter/thermistor
mount combi-
nation, measure
the signal
source RF output
level
and
record.
d.
Change
the frequency
to
another
point
and
reset
the
RF output
level to that
measured
in
step c.
e.
Disconnect the power meter/ thermistor
mount
from the
srgnal source
and
connect the
Detector.
The
SWRmeter indication
should
bewithil
1.0
dB
of
orig-
inal reference.
f.
Repeat
steps
b,
c,
d,
and
e
at
allpoints of interest
across
the frequency
band.
41.
SENSITIVTIY
CHECK.
a.
Using
a
10
MHz
ta
12.4 GHz
signal
source
and a
dc
voltmeter
as
the indicator,
connect the
Detector
to
the signal source
and
adjust the RF
power
level for
a
100
mW
detected output
from
the
Detector.
b.
Disconnect
the
Detector from
t}te
signal
source
and
measure the
RF
output
level.
Specification:
less
tharr 0.355
mW should produce 100mV detectedoutput.
42.
SWR
CHECK.
a.
Equipment
required:
(1)
tP
250A
Rx
Meter
(2)
HP 803A
VHF
Bridge
(3)
HP
417A
Detector
(4)
HP 8098/8068/444A
Slotted
Line
Models
4234/847OA
(5)
P
805C
Slotted
Line
(6)
Si$ral sources:
10
MHz
to
18.4
GHz
b.
To
measure
the
S\[rR
of
the
Detector in
the
10
to
250
MHz
range an
RX meter should
be
used.
The
method
of
measurement
is
explained below.
c.
Using the
HP 250A
RX
Meter,
measure
the
re-
sistance
(R) and
capacitance
(C)
of
the
Detector. Cal-
culate
the
reactance
of
the
Detector from
the
equation:
X equals
1
divided by
2 times
3. 1416
times
the
fre-
quency
of
measurement (neglecting
the
sign
of
C).
Calculate
the
Q
(when
Q equals
R
divided by X).
d.
Calculate
the
Detector load
impedance
21 from
the
equation:
zt
=n
where
ZL
= Detector
load
impedance
e.
Calculate
the
SWR
of
the
Detector from
the
fol-
lowing
two
equations:
(1) o=(zt/zd-t'
(zy/zs)
+
|
1
(2)
swR =
i++
where
p =
reflectioncoeffieient
Zo =
characteristic
impedance
f.
To
measure
SWR
in
the 250-MHz
to
500-MHz
range use
HP
803A and
HP
417A.
g.
To
measure
SWR
in 500- to
4000-MHz
use
805C
Slotted
Line
and
4158
SWR
Meter.
h.
Tomeasure
SWR
in 4-to
12.4-GHz range usethe
HP 8098/8068/444A
Slotted
Line
combination.
t
\r'
01613-8
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