Atec Tektronix-1502 - Manual (Page 22)

TM 9-4935-601-14-3&P
Fig. 2-7 is a chart for converting reflected pulse amplitude to impedance. Rho is dependent on the
characteristic impedance, Z
o
, of the cable under test and the load (or the impedance of the discontinuity), R
L
,
on the cable. Therefore, p can also be defined as:
R
L
- Z
o
R
L
+ Z
o
This relationship was used to develop the chart shown in Fig. 2-7.
Figure 2-6. TDR Display of R
L
vs Z
o
.
TYPICAL CABLE PROBLEMS
A few of the cable problems that can be analyzed with the 1502 include opens, shorts, pin-holes in the
cable shield, opens in the shield, kinks in the cable, mismatched connectors, and corroded connectors. Figs. 2-
8 through 2-11 show typical examples of these problems.
Figure 2-7. Impedance Nomograph.
REV C JUL 1980
p =
2-7