Delayed-Sweep Magnification - Tektronix 2337 Instruction Manual

DELAYED-SWEEP MAGNIFICATION
The delayed-sweep feature of the 2337 can be used to
provide higher apparent magnification than is provided by
the X10 MAG function. Apparent magnification occurs as
a result of displaying a selected portion of the A trace at
a faster sweep speed (B Sweep speed). The A SEC/DIV
switch setting determines how often the B trace will be
displayed. Since the B Sweep can occur only once for each
A Sweep, the A Sweep time duration sets the amount of
time elapse between succeeding B Sweeps.
The intensified zone is an indication of both the location
and length of the B Sweep interval within the A Sweep
interval. Positioning of the intensified zone (i.e., setting
the amount of time between start of the A Sweep and start
of the B Sweep) is accomplished with the B DELAY TIME
POSITION control. With either the A INTEN or the B
HORIZ MODE selected and with the B TRIGGER
SOURCE switch set to RUNS AFTER DLY, the B DELAY
TIME 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 any
location within the A Sweep interval. When the A INTEN
HORIZ MODEis selected, the B SEC/DIV 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" procedure which
follows the discussion of "Magnified Sweep Runs After
Delay."
When looking at a signal having pulse jitter, it is often
useful to be able to hold that signal stationary on the
screen. Operating the B Sweep in a triggered mode will
produce a more stable display, since the delayed display is
triggered at the same level each time. This capability is
provided by the 2337 and is explained in the "Triggered
Magnified Sweep" discussion.
Magnified Sweep Runs After Delay
The following 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 Normal
Sweep Display.
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