Triggered Delayed Sweep Magnification; Displaying Complex Signals Using Delayed Sweep; Using Delayed Sweep For Magnification - Tektronix 7B92A Instruction Manual

Operating Instructions-71392A Operators
PULSE TO BE
1752-11
Fig . 2-10 . Using delayed sweep for magnification .
6 . Position the start of the intensified portion with the DE-
LAY TIME MULT dial to the part of the display to be mag-
nified .
7 . Set the DLY'D Time/Division switch to a setting which
intensifies the full portion of the display to be magnified .
The start of the intensified trace will remain as positioned
in step 6 .
8 . Press in the DLY'D Time/Division switch for the Delayed
Sweep mode .
9 . Time measurements can be made from the display in the
conventional manner . Sweep rate is set by the DLY'D Time/
Division switch .
10. The apparent sweep magnification can be calculated by
dividing the TIME/DIV OR IDLY TIME switch setting by the
DLY'D Time/Division switch setting .
Example : The apparent magnification of the display shown
in Fig . 2-10 with a TIME/DIV OR IDLY TIME setting of
2- 1 6
200 ns and a DLY'D Time/Division switch setting of 20 ns
is :
Apparent
Magnification
Substituting the given values :
Apparent
Magnification
_ TIME/DIV OR IDLY TIME setting
DLY'D Time/Division setting
200 nanoseconds =
10
20 nanoseconds
Triggered Delayed Sweep Magnification
The delayed sweep magnification method just described,
may produce too much jitter at high apparent magnification .
The Delayed Sweep Triggerable mode provides a more stable
display, since the delayed sweep display is triggered at the
same point each time .
1 . Set up the display as given in steps 1 through 7 in the
Delayed Sweep Magnification procedure .
2 . Rotate the Delayed Triggering LEVEL control counter-
clockwise out of the RUNS AFTER DELAY TIME detent .
Select the desired Delayed Triggering SLOPE, COUPLING,
and SOURCE .
3 . Adjust the Delayed Triggering LEVEL control to produce
an intensified portion on the display .
4 . Inability to produce an intensified zone on the display
indicates that the Delayed Triggering controls are incorrect-
ly set . If the condition cannot be remedied with the Delay-
ed Triggering controls or by increasing the display amplitude
(lower volts/division setting), externally trigger the delayed
sweep .
5 . When the correct portion of the display is intensified,
press in the DLY'D Time/Division switch for the Delayed
Sweep mode, slight readjustment of the Delayed Triggering
LEVEL control may be necessary to produce a stable delay-
ed sweep display .
6 . Measurement and magnification are as described in the
Delayed Sweep Magnification discussion .
Displaying Complex Signals Using Delayed Sweep
Complex signals often consist of a number of individual events
of differing amplitudes . Since the trigger circuits are sensitive
to changes in signal amplitude, a stable display can normally
be obtained only when the sweep is triggered by the event(s)
having the greatest amplitude . However, this may not produce
the desired display of a lower-amplitude portion which follows
the triggering event . The delayed sweep feature provides a
means of delaying the start of the delayed sweep by a selected
amount following the event which triggers the Main Sweep
Generator . Then, the part of the waveform which contains
the information of interest can be displayed at the delayed
sweep rate .