iv) Place the transmitter on the ground at a known location
directly above the line that you want to energize. As
depicted in
Figure 5
, it is important to place the transmit-
ter vertically and in the direction of the underground line.
Since the transmitter radiates a signal directionally, this
orientation over the line will optimize the signal transfer
into the line. With improper placement or orientation, it is
possible to cause little or none of the signal from the
transmitter to actually energize the line.
NOTE: It should be known that when placed over a line to ener-
gize it, the transmitter radiates signals from the sides and
top as well as from the bottom. Signals radiated through
the bottom are used to energize the line. Those coming
from the sides and top travel a short distance through the
air and are attenuated.
If the transmitter is aligned perfectly with the underground
line, the signals emerging from the sides will travel along
the path of the line. This can cause some confusion when
working close to the transmitter. To avoid such confusion,
offset the transmitter 10° or 15° from the general direction
12
