HP 5245L Service Manual

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 e,45L
IJ!\ItrIEFI
TEEiT
DY-2460 A/
Dv-z46tA"MZ
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-?

HP 5245L Specifications

General

Brand	HP
Model	5245L
Category	Cash Counter
Language	English