Tektronix 7A26 Instruction Manual page 8

source for each position of the DISPLAY MODE switch is
CH 2 Channel 2
ADD Algebraic sum of channel 1 and channel 2
CHOP Algebraic sum of channel 1 and channel 2
When the IDENTIFY button is pressed, the trace is
deflected about 0.2 division to identify the 7A26 trace.
This feature is particularly useful when multiple traces are
displayed. When the IDENTIFY button is pressed on instru-
ments with readout, the deflection factor readout is
replaced with the word "IDENTIFY".
20 megahertz.
BASIC APPLICATIONS
General
The following information describes the procedures and
techniques for making basic measurements with a 7A26 and
the associated TEKTRONIX oscilloscope and time-base.
These applications are not described in detail since each
application must be adapted to the requirements of the
individual measurements. This instrument can also be used
for many applications not described in this manual. Contact
your local TEKTRONIX Field Office or representative for
assistance in making specific measurements with this
Peak-to-Peak Voltage Measurements (AC)
To make peak-to-peak voltage measurements, use the
following procedure:
1. Apply the signal to either input connector.
2. Set the DISPLAY MODE and TRIGGER SOURCE
switches to display the channel used.
3. Set the coupling switch to AC.
NOTE
For low-frequency signals below about 30 hertz use
the DC position to prevent attenuation of the signal.
4. Set the VOLTS/DIV switch to display about five
divisions of the waveform vertically.
5. Set the time-base Triggering controls for a stable
display. Set the time-base unit to a sweep rate which
displays several cycles of the waveform.
6. Turn the 7A26 POSITION control so the lower
portion of the waveform coincides with one of the graticule
lines below the center horizontal line, and the top of the
waveform is within the viewing area. With the time-base
Position control, move the display so one of the upper
peaks lies near the center vertical line (see Fig. 1-4}.
7. Measure the divisions of vertical deflection peak-to-
peak. Check that the VARIABLE (VOLTS/DIV) control is
in the CAL IN position.
This technique can also be used to make measure-
ments between two points on the waveform, rather
than peak to peak,
8. Multiply the deflection measured in step 7 by the
VOLTS/DIV switch setting. Include the attenuation factor
of the probe if used.
/ Centerline
f
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VN
Fig. 1-4. Measuring the peak-to-peak voltage of a waveform.
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