Delay Time Multiplier; Delayed Sweep Triggering - Tektronix 7B92A Maintenance Manual

Fig. 1-6. Typical alternate sweep display.
The TRACE SEP control vertically positions the
intensified trace up to 3.5 divisions above the delayed
sweep trace. The brightness of the intensified zone may
be varied by the CONTRAST adjustment.
brightness of the intensified sweep may be varied by the
7B92A INTENSITY control.
Intensified Sweep Mode.
sweep mode is selected when the DLY'D Time/Division
switch is pulled out, rotated to the desired sweep rate
faster than the TIME/DIV OR DLY TIME switch setting,
and the TRACE SEP control is rotated counterclockwise
to the ALT OFF position.
Delayed Sweep Display. The Delayed sweep
display mode is selected when the DLY'D Time/Division
switch is pulled out, rotated to the desired sweep rate,
and then pushed in.
sweep is displayed.
Calibrated sweep rates in the Delayed sweep
mode are available from 0.2 s/Div to 0.5 ns/Div.
using the VARIABLE control (Time/Div Variable Selector
connector set for variable delayed sweep rates),
uncalibrated delayed sweep rates to 0.5 s/Div are
available. Triggering for the delayed sweep is controlled
by the Delayed Triggering controls.
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The Intensified
In this mode, only the delayed

Delay Time Multiplier

The DELAY TIME MULT dial (functional in the
Delayed, Intensified, Alternate, or Mainframe Delaying
modes) provides 0 to 9.8 times continuous sweep delay.
The amount of time that the delaying sweep runs before
the start of the delayed sweep is determined by the
settings of the TIME/DIV OR DLY TIME switch and the
DELAY TIME MULT dial.
For example, a DELAY TIME MULT dial setting
of 3.55 corresponds to 3.55 crt divisions of delaying
sweep. Thus, 3.55 multiplied by the delaying sweep rate,
indicated by the TIME/DIV OR DLY TIME switch, gives
the calibrated delay time before the start of the delayed
sweep.

Delayed Sweep Triggering

The
determines the delayed triggering mode, and delayed
triggering level. When the LEVEL control is in the RUNS
AFTER DLY TIME detent position (fully clockwise), the
delayed sweep starts immediately after the delay time
(determined by the TIME/DIV OR DLY TIME switch and
DELAY TIME MULT dial). This mode permits selection
The
of continuously variable delay times by rotating the
DELAY TIME MULT dial.
LEVEL control and SLOPE, COUPLING, and SOURCE
switches are inoperative.
When the delayed sweep is triggerable (Delayed
Triggering LEVEL out of the RUNS AFTER DELAY
detent), the delayed sweep does not start at the
completion of the delay time. Instead, it waits until a
trigger pulse is received by the Delayed Triggering
circuits. The delay time in this mode is dependent not
only on the settings of the delay time controls, but on the
Delayed Triggering controls and the occurrence of the
delayed-sweep triggering signal as well.
purpose of this mode is to eliminate jitter from the
delayed sweep is triggered by the input waveform, jitter is
eliminated from the delayed sweep display even though it
may be inherent in the input waveform. When jitter in the
By
delayed sweep display is not a problem, the Runs After
Dly Time mode should be used.
In the Delayed Sweep Triggerable mode, the
Delayed Triggering LEVEL control is rotated to select the
amplitude point on the trigger signal at which the delayed
sweep is triggered. The Slope, Coupling, and Source
functions are the same for delayed triggering as for
MAIN TRIGGERING (see MAIN TRIGGERING SLOPE,
COUPLING, SOURCE, and TERM switch discussions in
this section).
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Operating Instructions—7B92A
Delayed Triggering
The Delayed Triggering
LEVEL control
The primary