Ditch Witch 150RT - Manual (Page 43)

Locating Concepts - 42
150R/T Operator’s Manual
Common Signal Problems
CMW
Common Signal Problems
Distortions in the electromagnetic field around a line can affect location accuracy. Tees, bends, parallel
lines, crossing lines, or large metallic objects can distort signals.
Learn to recognize the following kinds of distortion:
Shadows
Shadows, also called blind spots, often happen when a metallic object partially obstructs the signal, or a
signal from a parallel line interferes with target signal.
False Signals
False signals describe situations where the receiver indicates a line location where there is no line. False
signals often happen when a line tees or bends, runs parallel to the target line, or crosses the target line.
Secondary (Ghost) Signals
A typical beacon signal pattern shows a main signal and two weaker secondary signals. Identify beacon
location at the main signal. Familiarity with beacon signal patterns will lessen the effect of ghost signals.
IMPORTANT: If target depth and location are critical, confirm by hand-digging or vacuum excavation.
IMPORTANT: Generally, the receiver shows less distortion in peak antenna configuration.