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Tracking
-
The
check on meter tracking should be performed follow-
ing
the
calibration and
tuning
eye adjustments
.
The test
equi
pment is con-
nected as shown
in Fig
.
18
,
and circuit conditions will be the same as
detailed
in paragraph
1 of the tuning
eye adjustment
.
NOTE
:
The DB scale on
the
Model
416A meter is calibrated in
power
ratios (10
log~)
of the rf inputs to the
square
-
law detectors,
P2
whereas
the DB
calibration of
the Model 350A (or B) is based
on
power ratios
proportional to the
square of the voltages
(20
log
E1).
Therefore
a 2
db
setting on the
Model 350A
E2
(or B) corresponds
to 1
db on the Model 416A meter scale.
Scale Tracking
:
1.
The RANGE switch on
the
Model 416A
is at
the 0 DB 100% position.
2
.
To check scale
tracking
,
attenuation inserted
by attenuator #2 is
increased in
4
-
db
steps
.
The level of
reflected voltage
,
as indicated by the
Model 416A meter
should
drop
in 2
-
db steps,
as
i
ndicated in the
following
table.
Atten
.
#2
Model 416A
Meter
Setting
Reading
,
DB
Scale
0 DB
0
4 DB
2
8 DB
4
12 DB
6
16 DB
8
20
DB
10
3.
Return the setting of
attenuator #2 to 0
DB
.
Range
Tracking
:
1.
·
To
check the range
tracki
ng
,
attenuation
of
the
reflected
voltage
is increased at
attenuator
#2 in 20
-
db
s
t
eps
.
The Model 416A
meter
indic
-
ation
should
follow in
10
-
db
steps the changes in attenuation
,
as
indicated
in
the
following
table
.
-
55
-
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