A common mistake when testing through bridged taps
is to mis-identify the end of the lateral for the end of the
main cable circuit. As shown below, Figures 1a and 1b
show two different cable plant layouts. However, the
resulting waveforms are
identical
.
Figure 1a
Figure 1b
In Figure 1a, the length of the lateral is shorter than the
end of the main cable circuit. In Figure 1b, the length of
the lateral is longer than the main cable circuit.
LESSON:
Do not assume the first upward
reflection after a bridged tap is always the end