Fundamentals; Getting A Display - Tektronix 2465A Operator's Manual

Operation
Fundamentals
Like any oscilloscope, this instrument draws a graph of voltage as a function of
time. The VERTICAL controls, marked off by a heavy gray line, define the voltage axis
of the display. SEC/DIV, X10 MAG, and horizontal POSITION control the time axis of
the display. The TRIGGER controls, marked off by a green box, define the signals
required to initiate sweeps across the time axis. The controls under the CRT affect the
display but not the waveform.
Getting
a
Display
1. Connect a probe from the input of a Vertical channel to a signal.
2. Select the channel using the Vertical MODE buttons. You may select any
combination of vertical channels (if you are using the standard accessory
probes, make sure the CH 1 and CH 2 input are not set at 50 [I).
3. Press AUTO Setup to initialize vertical, horizontal, trigger, and display intensity
for a usable display. (If STEP is illuminated, first push RECALL to extinguish
it.)
4. If the resulting display isn't exactly what you want, adjust the appropriate
VOLTS/DIV, SEC/DIV, POSITION, or Trigger controls.
Characteristics of AUTO Setup
With one channel, Auto Setup centers the a-volt level and makes the vertical
display as large as possible, within the graticule. With more than one channel,
the a-volt levels of CH 1, CH 2, CH
3,
and CH 4 are set at +2, 0, -2, and
-3
divisions from center, respectively. When ADD is displayed, the O-volt level of
CH 2 is set at - 2 divisions.
AUTO sets Sec/Div within the range from 20 ns to 2 ms, to show two to
five cycles of most signals. With narrow, low repetition-rate pulses, the sweep
runs faster to stretch out the display, with the appropriate trigger slope.
AUTO Setup sets the trigger for Auto Lvi Mode, Vert Source, DC Coupling,
and Min Holdoff, with level at the midpoint between signal peaks.
The STEP/AUTO EXT SWITCH connector on the rear panel produces the
same functions as the STEP/AUTO button, in response to a switch closure or
TTL-low signal.
See "Save and Recall Operation" for the sequence function of Step/Auto.
2465A/2455A/2445A Operators 2-1