Model 1707B Operation
NOTE 3-69. AUTO VERSUS NORM.
Intensified portion should cover 4 ?j 3-70. In AUTO operation, there will always be a base
to 5 divisions. line. A trigger signal of 40 Hz or higher overrides
AUTO operation and produces a stable pre-
sentation. Adjustment of main TRIGGER LEVEL may
be necessary for a stable display. If the trigger is
less than 40 Hz, or if it is unstable, NORM opera-
f. Adjust DELAY TIME until intensified portion tion should be used. A trigger signal is always
is centered on CRT. needed in NORM operation to generate a sweep.
g. Set sweep display switch to DELAYED 3-71. AUTO VERSUS TRIG.
SWEEP. Observe that intensified portion is expanded
to full 10 divisions. 3-72. Auto delayed sweep operation is achieved
when AUTO/TRIG pushbutton is out. This causes
h. Set sweep display switch to MAIN SWEEP. the delayed sweep to start at the end of delayed
time as set by the DELAY TIME control.
i. Vary DELAY TIME control. Observe that in-
tensified portion moves smoothly along display.
3-73. AC VERSUS DC.
j. Set delayed AUTO/TRIG control to TRIG.
3-74. Ac coupling removes the dc level of trigger
k. Adjust delayed TRIGGER LEVEL for stable signals operations. Use of the LF RE J control prevents
intensified portion of the trace. low frequency noise from triggering the sweep.
1. Vary DELAY TIME control. Observe that 3-75. MIXED SWEEP.
leading edge of intensified portion jumps from one
positive slope leading edge to next. 3-76. In this mode, the first part of the present-
ation is displayed on a time base set by the main
m. Set delayed TIME/DIV to OFF.
TIME/DIV switch. The last part of the presentation
\ n. Rotate main VERNIER counterclockwise to is displayed on a time base set by the delayed TIME/
l stop. Observe 15 or more pulses between first DIV switch. The delay between the start of the
and eleventh graticule lines. main sweep and the start of the delayed sweep is
determined in part by the DELAY TIME control.
0. Disconnect calibrator signal from vertical am-
plifier.
3-77. DELAYED SWEEP.
p. Set main TIME/DIV to .1 SEC. 3-78. Signals can be displayed at 100 ns/div with
3% accuracy. Displays can also be expanded up to
q. Set main TRIGGER LEVEL to full clockwise 10 ns/div (XI0 magnification) with 5% accuracy.
position. This expansion permits viewing critical rise time or
signal shapes with increased resolution. The portion
r. Set main AUTO/NORM to NORM.
to be expanded is selectable by the DELAY TIME
control in main sweep operation. It is then expanded
s. Select SINGLE operation.
to the sweep speed selected by the delayed TIME/
DIV switch after delayed sweep operation is selected.
t. Press RESET pushbutton. Reset indicator Because the sweeps are independent, the main
should go on. Observe no sweep.
VERNIER may be out of CAL position while the
u. Rotate main TRIGGER LEVEL to full counter- delayed sweep is still calibrated.
clockwise position. Observe one sweep and reset 3-79. Sweep jitter can be reduced by use of the
indicator goes off after sweep.
delayed operation. By using TRIG mode instead of
v. Set AUTO/NORM to AUTO. AUTO in delayed sweep operation, the delayed sweep
starts on a new trigger. This reduces the jitter
w. Press RESET pushbutton. Observe one sweep. that has accumulated since start of the main sweep.
3-80. LINE SYNC.
3-67. OPERATING INFORMATION.
3-81. Line sync is selected by depressing both
) 3-68. The following paragraphs provide additional main HF REJ and LF REJ pushbutton. This method
information concerning the use of some specific of time base synchronization is useful when observing
functions. waveforms that are timerelated to the line frequency.
3-7 |
ACEC
HEWLETT-PACKARD
