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78-9000-5020-0 Rev C
E. Directional Null (DirNull)
TRACE [3] + Mode [SK] + DirNull [SK Toggle]
or Menu/OK [6] + Cable/Pipe [SK] + Mode [SK] + DirNull [SK Toggle]
In Directional Null mode, as the operator approaches the cable or pipe, the numerical
Signal Strength
will increase then fall sharply as the receiver crosses the target cable or
pipe. The
Bar Graph
fills from both sides toward the middle and the receiver speaker
volume decreases. As the antenna moves off the target path, the
Bar Graph
opens, the
Signal Strength
increases, and the speaker volume increases. Gain adjust is automatic in
Directional Null mode.
The center of the DirNull display provides a ‘compass view' of the target path. An arrow
will point toward the location of the cable/pipe in 45-degree steps. A solid line will
appear over the cable/pipe, indicating its orientation to the receiver handle.
For example:
Figure 1:
If the target path is to the right of the
receiver, and running parallel to the receiver handle,
the right arrow will display.
Figure 2:
If the target path is to the left and in front
of the operator (not running parallel to the receiver
handle) the arrow will point toward the top left side
of the display.
Figure 3:
When the receiver crosses the target path,
a solid line will appear, instead of arrows, indicating
the target path and its orientation to the receiver
handle.
Before marking target path, always use Directional Peak or, Special Peak mode to verify
location.