Delayed-Sweep; Magn Ifickl-Ion; Magnified Sweep Runs After Delay - Tektronix 2235A Instruction Manual

Operatlng lnstructlons- 2235A lnstructlon
clockwise (RUNS AFTER DLY), the
B
DELAY TlME
POSITION control provides continuously variable
positioning of the start of the B Sweep. The range of this
control is sufficient to place the B Sweep interval at most
any location within the A Sweep interval. When ALT Hori-
zontal MODE is selected, the B SECIDIV switch setting
determines the B Sweep speed and concurrently sets
the length of the intensified zone on the A trace.
Using delayed-sweep magnification may produce a
display with some slight horizontal movement (pulse
jitter). Pulse jitter includes not only the inherent
uncertainty of triggering the delayed sweep at exactly
the same trigger point each time, but also jitter that may
be present in the input signal. If pulse jitter needs to be
measured, use the Pulse Jitter Time Measurement pro-
cedure which follows the discussion of Magnified
Sweep Runs After Delay.
Magnified Sweep Runs After Delay
The followirlg procedure explains how to operate the B
Sweep in a nontriggered mode and to determine the
resulting apparent magnification factor.
1. Preset instrument controls and obtain a baseline
trace.
2. Apply the signal to either vertical channel input
connector and set the Vertical MODE switch to dis-
play the channel used.
3. Set the appropriate VOLTSIDIV switch to produce a
display of approximately 2 or 3 divisions in ampli-
tude and center the display.
4. Set the A SECIDIV switch to a sweep speed which
displays at least one complete waveform cycle.
5. Select A C T Horizontal MODE. Adjust both the appro-
priate channel POSITION control and the A/B SWP
SEP control to display the A trace above the B trace.
INTENSIFIED ZONE
TO BE MAGNIFIED
( A ) A INTENSIFIED DISPLAY
(0) B DELAYED DISPLAY
4207-2 1
Figure 2-19. Delayed-sweep magnification.
7. Set the B SECIDIV switch to a setting which intensi-
fies the full portion of the A trace to be magnified. The
intensified zone will be displayed as the B trace (see
Figure 2-19). The B Horizontal MODE may also be
used to magnify the intensified portion of the A
Sweep.
8. The apparent sweep magnification can be calcu-
lated from the following formula:
Apparent A SECIDIV switch setting
Delayed Sweep
=
Magnification B SECIDIV switch setting
EXAMPLE: Determine the apparent magnification of
a display with an A SECIDIV switch setting of 0.1 ms
per division and a B SECIDIV switch setting of 1 ps
per division.
Substituting the given values:
6. Adjust the B DELAY TlME POSITION control to
position the start of the intensified zone to the portion Apparent
-
1
X
! 3
=
I@?
=
I()o
of the display to be magnified (see Figure 2-19).
Magnification
-
1
x
10- s
Scans
by ARTEK MEDLA
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