Basic Applications-2465 Operators
the length
of the zone. The intensified zone on the A
Sweep trace
is
used to identify the point of interest to be
examined or measured, while the alternate
B
Delayed
Sweep trace magnifies and displays the intensified segment.
Apparent horizontal magnification of the waveform occurs
as
a
result of displaying the selected portion of the A Sweep
at
a
faster
B
Sweep speed.
Vertical separation of the A and
B
Sweep traces is
variable using the TRACE SEP control. The control has
enough range to position the
B
Sweep trace from zero
(overlayed on the A Sweep trace) to three or more divisions
downward from the A Sweep trace.
Time measurements can be readily made on waveforms
by employing the
DLY
readout and the
A
REF OR DLY
POS control. Delay time from the A trigger point to the
beginning of the
B
Sweep
is
read directly from the
DLY
readout in the crt display. After noting a first delay-time
position,
a
second measurement point can be aligned with
the same reference graticule line, and the new delay time
read. Time difference between the two points
is
then
determined by computing the difference between the two
delay-time readings. The computed time difference between
the two delay times
is
more accurate than either of the
delay-time readings.
NOTE
If the Tracking mode of delay-time positioning is
selected (TRACKING/INDEP button in), the
A
REF
0
R DL
Y
POS control simultaneously moves both the
Reference and the Delta delays equal amounts, The
A
control, however, continues to independently
position the Delta delay regardless of the position of
the TRA CKING/INDEP button.
Delta Time measurements using the A lntensified
Horizontal Display mode are made by simply setting the
start of each intensified zone to the separate measurement
points and noting the At readout in the crt display. This
method produces the least accurate results, since
it
is
difficult to determine exact alignment with the measure-
ment points.
Much more accurate measurements are possible using
the Alternate Horizontal Display mode. In this mode,
a
separate
B
Delayed Sweep trace
is
present for each
displayed intensified zone. As explained before, the inten-
sified zones are positioned to the points of interest; but
instead of aligning the start of the zones to the measure-
ment points, both the Reference and the Delta delays are
adjusted to overlay the two points precisely, using the
respective
B
Delayed traces. An example application of this
method
is
given in the following procedure.
5
Delayed Horizontal Display Mode
Once the point of interest to be examined or measured
is
This procedure describes the steps necessary to make
identified, the A lntensified Sweep trace can be eliminated
time measurements between two time-related pulses applied
on separate input channels. However, the same principles
to provide an uncluttered display for
ease
of viewing.
Displaying only the
B
Delayed Sweep (PUSH-6)
is
accom-
apply for measuring time differences between successive
pulses, pulse periods, or other time intervals on
a
single-
plished by pushing in the
B
SECIDIV knob after first
channel
input
signal.
establishing the Alternate Horizontal Display mode. Pulling
the
B
SECIDIV knob back out returns the
A
lntensified
trace to the display, if needed to reidentify
a
measurement
point. Rotating the
B
SECIDIV knob back to the same
setting
as
the A SECIDIV switch, with the
B
SECIDIV
knob pushed in, locks the two knobs together and returns
the Horizontal Display mode back to A Sweep only.
Delta Time Feature with Delayed Sweep
The Delta Time function can be used in any of the
delayed-sweep modes to obtain direct-reading time-
difference measurements. When activated, two separate.
B
Delayed Sweep intervals are produced in the A Sweep
interval. Delay time for each
B
Sweep interval is
independently adjustable. The
A
REF
OR DLY POS
control positions one of the delay times, usually referred
to
as
the Reference intensified zone or the Reference delay.
Positioning of the second delay time, referred to
as
the
Delta intensified zone or the Delta delay,
is
accomplished
with the
A
control.
1.
Preset instrument controls and obtain
a
baseline trace.
2.
Using either probes or cables with equal time delays,
apply
a
known reference signal to the CH
1
OR
X
input
connector and apply the comparison signal to the CH
2
input connector.
NOTE
If the repetition rates of the pulses to be measured
are not the same, use the slower repetition-rate signal
as the Trigger SOURCE signal. Using the faster
repetition-rate signal as the Trigger SOURCE will
present multiple triggering-point possibilities during
the period of the slower signal.
3.
Select both CH
1
and CH
2
VERTICAL MODE.
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