Operating Instructions
1–16 1502C MTDR User Manual
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ac 452.000 ft
Open
Figure 1–11: 455-ft Cable
5. Change DIST/DIV to 20 ft/div. The entire cable can now be inspected in
detail on the LCD. Turn the
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POSITION control so the cursor travels to
the far right side of the LCD. Keep turning and the cable will be “dragged”
across the display.
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ac 452.000 ft
Short
Figure 1–12: 455-ft Cable
A “rise” or “fall” is a signature of an impedance mismatch (fault). A dramatic
rise in the pulse indicates and open. A dramatic lowering of the pulse indicates a
short. Variations, such as inductive and capacitive effects on the cable, will
appear as bumps and dips in the waveform. Capacitive faults appear as a
lowering of the pulse (e.g., water in the cable). Inductive faults appear as a rising
of the pulse (e.g., fray). Whenever an abnormality is found, set the cursor at the
beginning of the fault and read the distance to the fault on the distance window
of the LCD.