HP 5245L - Page 43

I
Model
5245L
Table 3-2. In-Cabinet
Performance Check
(cont'd)
b. Counter should
count
10,000.000
kHz. The change
in
count
should be
visible
on each digital display
tube.
c. Set Counter
STORAGE
switch
to the STORAGE
position.
The
Counter
should
count, display,
and
hold
10,000,000
kHz
count
providing
a
continuous display
of the
most recent
count. Record
results
on test card.
SAffIPtE RATE
1.
Sample Rate:
Variable
from
less
than
.2
sec
to
greater
than
5 seconds.
a.
Set Counter
controls as follows:
SENSITMIY
to
CHECK
SAMPLE
RATE
tO POWER
OFF
TIME BASE
to
10
ms
FUNCTION
to
FREQUENCY
-
LEVEL +
to
PRESET
b. Connect Oscilloscope
to
Jl1
Pin 48.
c. Turn
the
Counter
SAMPLE
RATE
control
slightly
clockwise out of
POWER OFF, and note that the
Counter turns
on.
d. With
the SAMPLE
RATE control in
ma.:<imum
position
(ccw),
observe
with
oscilloscope the
negative
pulse
duration
between
gate
closing and the
following
gate
opening;
it
should
be less than 200 milli-
seconds
(.2
sec).
e. Increase
the SAMPLE
RATE control
clocl$vise
to
minimum
sample
rate. Observe with Oscilloscope
the
negative
pulse
duration between
gate
closing
and
the following
gate
openingl
it
should be
more
than 5
seconds.
f.
Set
the SAMPLE
RATE control to the
Hold
position.
The last
Counter
reading
should remain
dis-
played
indefinitely.
Record results on
test
card.
DIGITAI OUTPUT
1
Output
4
line
l-2-2-4 BCD:
Impedance
100K
each
line
"0"
State
Level
-8V
"1"
State
Level +18V
a,
The impedance
is determined
by a
fixed
value 100K
resistor,
which can
be seen
in
schematic
diagrams Figures
7-9
,
?-11
,
and
?-
14.
b.
Set Counter controls
as
follows:
SAMPLE
RATE
slightty
clockrvise
out
of POWER OFF
SENSITMTY
to
.
ls
TIME
BASE to
1
/.rs
FUNCTION
to
MA}IUAL
START
MODE
(rear
panel)
to INT STD FREQ
c.
Connect
Oscilloscope
to
following
points
to
verify
"0"
state
and
'r1'r
state
levels.
Oscilloscope will
display
the switch from
"0"
state
(-8
volts)
to
"1"
state
(+18
volts) as a
positive
26
volts
step.
Check all recorder
outputs for
"0"
state
and
"1"
state
and mark
the test card ok.
Section
trI
Table
3-2
02349-1
3-9