IBM 5500 Operational, Installation, And Maintenance Manual page 123

Notice the steep slope changes that occur at the point indicated by the short.
A reflection of more than 10% of the transmitted signal, if measured within
100 m (328 ft) of the fault, usually indicates an undesirable impedance
change.
0.2 V
A=20 µs
B=0.2 µs
Figure 56: Short to Shield
Figure 57 shows the same condition as in Figure 56 but with the alligator clips
interchanged. In this figure, the same short is easier to identify because of the
incident wave signal being referenced to ground.
0.2 V
A=20 µs
B=0.2 µs
Figure 57: Short to Shield (Oscilloscope Leads Swapped)
Short
Short to Shield
Short to Shield
Short to Shield
55E1I033
55E1I034
123