[EXAMPLE]
In the example, the first dial reading is 0.61 and the second
is
5.78
with
the A
SWEEP
TIME/DIV setting at 2 /is.
Substituting the appropriate values. (See Fig. 34)
Pulse
width
=
(5.78-0.61)x2
(/is) = 10.34 /is
FREQUENCY MEASUREMENTS
USING
DELAYED
SWEEP
The
frequency is obtained as the reciprocal of the period of
one
cycle.
1.
Measure the period of the waveform using the pro-
cedure
described above for
time
measurement.
2.
The frequency is then the reciprocal of the period
measured.
Using
the formula:
Freq=
Period
PULSE REPETITION TIME
Using
the delayed sweep feature, reliable
time
measure-
ments can be made.
1.
Apply a signal to the INPUT jack and set the vertical
MODE to the channel to be
used.
Adjust
the VOLTS/DIV to obtain a normal
easy
to view
display
of the waveform are displayed.
2.
Adjust the A
SWEEP
TIME/DIV so
that
at least two
cycles
of the waveform are displayed.
Set
the HORIZ MODE to INT and set the B TRIG MODE
to affect the
AFTER
DELAY
mode of operation.
Set
the B
SWEEP
TIME/DIV as fast a sweep speed as
possible.
3.
Using the
DELAY
TIME MULT, adjust the intensified por-
tion
to coincide
with
the first pulse.
Set
the HORIZ MODE to ALT and use
TRACE
SEPARA-
TION to adjust the waveforms for
easy
viewing.
4. Using the
DELAY
TIME MULT, set the pulse to coincide
with
one of the vertical graduation lines and record the
dial setting at this point.
5. Again using the
DELAY
TIME MULT, adjust the second
pulse
in the same manner to the vertical line used in step
4, recording this dial setting as well. The pulse repetition
time
is the second dial reading minus the first dial
reading multiplied by the A
SWEEP
TIME/DIV control
setting.
Using
the formula:
Pulse
repetition
time=
(2nd dial reading —
1
st dial
reading) x Delayed sweep
time
(A
SWEEP
TIME/DIV
set-
ting)
[EXAMPLE]
For
the example, the period measured is 40.2 /is, making
the frequency simply. (See Fig. 35)
Substituting the given value:
Freq
=
1
/(40.2x
10"«) =
24.88
kHz
[EXAMPLE]
For
the example, the first dial reading is 0.76 and the se-
cond
is 6.22
with
the A
SWEEP
TIME/DIV set at 2 us.
We have, substituting the appropriate values. (See Fig. 36)
Pulse
repetition
time
=
(6.22-0.76)
x 2 (/*s) = 10.92 us
28
Fig.
35
Fig.
34
Read the dial setting when
B
sweep points
of
DELAY
TIME
MULT
©
and
©
are
in
the same
position.
Fig.
36
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