Operating Instructions—7B53A/7B53AN Operators
SINGLE
SWEEP, RESET-READY.
When
the signal to
be displayed
is not repetitive or varies in
amplitude,
waveshape,
or repetition rate, a conventional repetitive type
display
may produce
an unstable presentation. A stable
display
can often
be obtained
under these circumstances by
using
the
SINGLE SWP feature of
this unit. The SINGLE
SWP
MODE is also useful to photograph non-repetitive or
unstable
displays.
To obtain a
single-sweep
display of a repetition signal,
first
obtain the
best possible display in the
NORM MODE.
Then
without changing
the other MAIN TRIGGERING
switches, press
the SINGLE SWEEP
pushbutton.
When
ready
to view
the single-sweep
display, press the RESET
READY pushbutton.
A single trace is presented each time
the
RESET-READY pushbutton
is pressed (as long as the
repetitive
signal remains connected
to the
system
and
MAIN
TRIGGERING
switches
are correctly set); further
sweeps
cannot be presented until the RESET-READY
pushbutton
is
pressed again. If the display
signal is a
complex waveform
composed of
varying amplitude,
successive single-sweep displays may not start at the
same
point
on
the
waveform. To avoid
confusion due to the CRT
persistence, allow
the display
to disappear before
pressing
the
RESET-READY pushbutton
again. At fast sweep rates,
it
may be difficult to view the single-sweep display. The
apparent
trace intensity can be increased by
reducing the
ambient light level or
using a viewing hood
as recommended
in
the indicator oscilloscope instruction manual.
Non-repetitive,
random signals can be displayed in the
SINGLE
SWP MODE by first obtaining the best possible
display
in the NORM MODE
with a signal which is about
the same
amplitude and frequency as the random signal.
Then
without changing the
other MAIN TRIGGERING
controls, press the
SINGLE SWP pushbutton. When ready
for
the random signal, press the RESET-READY push
button. The
RESET-READY pushbutton remains
illumi
nated
to
indicate
that the unit has been
reset and is ready
to
produce a sweep. The
light goes out
after the single
sweep
has been displayed.
To prepare the
unit for another
single-sweep display,
press the
RESET-READY
pushbutton.
When
using the SINGLE SWP MODE to photograph
waveforms,
turn off
the
graticule illumination while
the
trace
is being photographed. Then the graticule can be
photographed
later
to produce a double-exposure
picture
showing
complete information. Further
information on
photographic
technique
is given in the appropriate camera
instruction manual.
Main
Triggering Coupling
The
MAIN TRIGGERING pushbuttons
located below
the COUPLING
title select
the method
in which the trigger
signal
is
connected to the trigger circuits. Each position
permits selection
or
rejection of the frequency components
of
the trigger signal which trigger the sweep. Fig. 1-5
graphically
illustrates the band of frequencies covered by
each position
of
the
COUPLING
switch.
Fig.
1-5.
Frequency range of each
COUPLING
switch position.
1-8
