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LBI -4097
MAINTENANCE
130
t20
ilo
too
90
80
70
60
50
40
30
20
to
3.
GE
Test Set
Mode1
4EX3A1O
or equivalent
mult imeter
.
Pfocedure
1.
Terminate one end of the I'Tt' connector
directly into a
50-ohm
load (no cable)
,
and connect
the
RF
Probe
directly into
the unterminated end as
shown
in
Figure
3.
2.
Place the Test Set on the I-volt
scale
and
set the amplifier
GAIN
control in
the
X5O
positj.on.
3.
Adjust the
BAI,ANCE
control for
zero
meter reading, and turn the
ATTENUATOR
control fully clockwise to the
CALIBRATE
posltion.
4
2.O
2.2
?.4 2.6
2,8
Adjust the signal generator output for
a meter reading of 0.1 volt on the
Test
Set.
Then
record the millivolt
reading
directly off of the signal generator.
Increase the signal generator output in
L/LO-volt steps
and
record the millivolt
readings.
The
readings can be plotted
on graph paper as
shown
in Figure
4.
U'
F
J
o
J
J
=
=
F
:f
o-
=
Lrl
o
o
E,
o-
o2
0.4 0.6
0.8
l.o 1.2 1,4 1.6
1.8
DC
OUT
PUT
VOLTAG
E
Figure 4 - TVpical Calibration
Curve
for
RF Probe
4.
5.
TThenever
three or
f
our of the
read-
ings fall
in a straight line in-
dicating that the output ls in-
creasing in a linear fashion with
the input (normally
between
I volt
and 1.6 volts).
The
straight line
may
be continued to
complete the
curve without further
measurements.
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