Service manual
Model 5304A
Operation
Figure 9D-3-7. Making Time Interval Measurements (Continued)
b. If the
input signals
are
pulse trains,
it is
possible
to
select
a
pulse
out of
the
train
by
increasing
the
DP]LAY
from full
ccw; the
measured time
interval will increase
in
steps
as the
delay falls after successive pulses
in the
train.
c. For
maximum flexibility
and
ease
of
interpretation,
an
oscilloscope
may be
used
to set up the
measurement
(as
shown
in
Figure
A). The
DELAY
OUTPUT
is
used
to
trigger
(he
time
base
and
intensity modulate
the dis-
play
(see
Figure
A). For a
repetitive
waveform,
the
Channel
A
input
may
fall during
the
display cycle,
and
therefore might
not
initiate
a
meas-
urement.
The
GATE output
may be
substituted
for the
DELAY OUTPUT;
this allows intensifying
the
actual
measurement rather than
the
delay.
If the
inputs
are
common,
the
GATE
OUTPUT
or
DELAY OUTPUT
can
be
displayed
on the
second channel
(or a
third channel
of a
four-channel
scope),
and the
other
of
these
two
used
to
intensity modulate.
d. Set
oscilloscope controls
as
follows:
HP 1801 A: Set A and B
Channel
controls
for a
display
of
both input
signal.
Set
DISPI
AY to A+B.
HP
182!A:
Set
TRIGGER
to EXT.
SLOPE
to -.
Coupling
to ACF.
SWEEP MODE
to
NORM.
Time/CM
for one
cycle
of
measured
Time Interval.
e. Set
DELAY slightly
out of
full
ccw
and
selcct
the
time interval delay.
The
SWEEP TIME
may
have
to be
readjusted.
f.
Adjust INTENSITY
to
view only
the
time interval measured.
g.
Oscilloscope time display
and
5300A
time readout should
be the
same.
Figure
B:
Example
of
Delay Control
CH A
INPUT
SIGNAL
CH B
INPUT
SIGNAL
GATE
SIGNAL
DELAY
OUT
SIGNAL
JUL
' I
{
I
' I
.TIME INTERVAL
HOLDOFF DELAY
TIME INTERVAL DELAY SETTING
Figure
A:
Delay Control Setup
1
'DELAY
OUT i
50 OHM
TERMINATIONS
EXT
INPUT
T I
STOP SIGNAL
T. 1.
START SIGNAL
SIGNAL
SOURCE
HPI80A
OSCILLOSCOPE
9! KM)