3. Operating Instructions
Table 3.4 (Continued) MENU Button and Menus
Menu Selection
Purpose/Action
Time of Flight
Show Time of Flight time measurements. The
standard nanoseconds display shows electrical time
for a pulse to reach a point and then return to the
CT100B.
Time of Flight is exactly half that value. It is the
one-way transmission time.
Vert Centering On/Off
When on, changes to vertical scale will center on the
point where the cursor intersects the selected trace.
When off, changes to vertical scale will center on the
center of the screen.
Draw Internal Cable Bkgrnd
Changes the background of the trace beginning from
the start of the trace to the end of the internal cable.
Auto Smooth Reset On Off
When on the CT100B will automatically reset
smoothing when a change in load is detected by the
device.
Scale
Toggles display of horizontal, vertical scales, and Vp.
Intersection
Toggles display of cursor-trace intersection.
Decibels
Toggles display of decibel (dB) values at cursor.
Temperature
Toggles display of instrument internal temperatures.
AutoSmooth On Off
When on, the CT100B will automatically pick a
smoothing value based on the observed noise.
When off, the CT100B will use the user-entered
smoothed value.
3.10. Test Preparations
If you would like a detailed explanation of TDR measurement theory and applications before
using the CT100B to test cables, please read Section 5,
, or go to
3.10.1. Connecting to the Cable or Device-Under-Test (DUT)
The first and most important decision to make when testing a cable or device-under-test (DUT)
is how to connect to the DUT. Because the connection to the DUT acts as a filter for the test
signal into and out of the DUT, it is very important that the connection have the highest
bandwidth and least aberration possible.
Controlled impedance connections are recommended whenever possible. Controlled impedance
connections have conductors with uniform geometry and dielectric properties that do not change
significantly during a test session or between test sessions. Examples of controlled impedance
connections include coaxial-coaxial adapters, coaxial-twisted pair adapters, and fixed-pitch TDR
probes.
CT100B TDR Cable Analyzers Operator’s Manual
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