Cable Test Procedure; Figure 1-8: 20-Ft Cable At 5 Ft/Div - Tektronix 1502C User Manual

Operating Instructions

Cable Test Procedure

Distance to the Fault
1–14
Be sure to read the previous paragraphs on Vp.
1. Set the 1502C controls:
POWER
CABLE
NOISE FILTER
VERT SCALE
DIST/DIV
Vp
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.
ac
O
N
O
F
F
O
F
F
O
F
F
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.
On
Cable to BNC
1 avg
500 mr
(see below)
(per cable)
0.000 ft
1502C MTDR User Manual