Operating Instructions
1–14
1502C MTDR User Manual
Cable Test Procedure
Be sure to read the previous paragraphs on Vp.
1. Set the 1502C controls:
POWER On
CABLE Cable to BNC
NOISE FILTER 1 avg
VERT SCALE 500 mr
DIST/DIV (see below)
Vp (per cable)
2. If you know approximately how long the cable is, set the DIST/DIV
appropriately (e.g., 20-ft cable would occupy four divisions on the LCD if
5 ft/div was used). The entire cable should be displayed.
O
F
F
O
F
F
O
F
F
O
N
ac 0.000 ft
Figure 1–8: 20-ft Cable at 5 ft/div
If the cable length is unknown, set DIST/DIV to 200 ft/div and continue to
decrease the setting until the reflected pulse is visible. Depending on the cable
length and the amount of pulse energy absorbed by the cable, it might be
necessary to increase the VERT SCALE to provide more gain to see the reflected
pulse.
Distance to the Fault