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Model 5245L
02349-1
o5245-A-
24
TabLe
3-2.
h-cabinet
Performance check
(cont'd)
Measure
the stability of the time base using the
circuit
shown
below
and
the
following procedure:
E
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IJ!\ItrIEFI TEEiT
DY-2460
A/
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IgI7 BFl
FIEF.
siTANtr'AFItrI
TEMPERATURE:
a.
Place the
Counter in
a
temperature-controlled environment. The rest of the
circuit
should
be
in
a constant
temperature environment.
b.
Set
controls of Counter under test as follows:
SAMPLE
RATE slightly clockwise out of pOWER OFF
MODE
(rear
panel)
to INT FREe
STD
OUTPUT
(rear
panel)
to
I
MHz
102
c.
Set
digital to
analog
converter to analgg colurryrs
4, 5,
and
6.
This gives
a
fuII
scale
plot
on the
strip
chart recorder of
10
parts in
10v.
set
the counter
(taute
5-1)
to
1. sec
TIME
BASE and
FIJNCTIoN
switch
to
10
pERIoD
AVERAGE.
Make a
reference-
plot with Counter at room
temperature.
Lower the temperature of the Counter
under
test
to -20'C
and
allow
3
hours
for
the Counter to reach thermal
equilibrium.
Make
a
ptot
of the output
and
record
any
change on
the
test
card.
Increase
temperatule gradually to
+Eb''C
and
allow
3
hours
for
thermal
equilibrium.
Make
a
plot
of the output
and
record any
change on
the
test
card.
Note
that the
change
in frequency shall not
exceed
i
2
parts in
1010
per
"C
"change
of ambient
temperature.
(If necessary set Converteir to columns
5, 6,
7
for
10
part" in
108
fuil
scale.
)
LINE VOLTAGE:
a.
Connect
the Counter under
test to
a
variable voltage power line
source.
Using
the same system
as
usgd
for
'emperature check, make
aplotwith
the
Iine voltage at
115V
rms. io*e"
the tine voltage
LQVo
to
103V
rms
and
make
a
second
plot,
Set
the line voltale
b
l}Vo aUove
normal
line,
12?V
rnis,
and
make
a
third
plot.
Record any
change
in frequency
on
test
card.
Note
that the frequency
change
is
less than
+5
parts in 10lu from
the
first
reference plot.
d.
e.
LONG
TERM STABILITY:
a.
The system should be in a constant
tion to stabilize the Counter.
Make
on
the
test
card.
Repeat
the
check
Temperature
and
line voltage
must
ferences must be
made.
temperature environment. Allow
72
hours of continuous opera-
a
reference plot
and
record the temperature
and
line
voltage
Ln
24
hours
and
record
any
change
in frequency
on
the
test
card"
be
the
sarne
as the
first
check
or
compensations
for
any
dif-
IMPEDANCE
TRANSFORMER
l0
514
A
MIXER
IKC
LO
PASS
FILTER
Section
III
TabLe
3*2
3-?
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