transmitter. (Detection could start well over 30 feet from the
transmitter’s actual location, depending on the type of
transmitter). When the antenna is exactly over the transmitter a
sharp signal loss or “null” will occur. As the antenna is moved on
either side of the null point the signal strength will again increase.
The receiver signal gain should be adjusted to suit the strength of
the transmitter and distance between transmitter and receiver.
In most cases, technicians find it convenient to use the internal
antenna to locate the transmitter at launch and trap facilities.
Depending on facility interference, the receiver is usually set on a
3/4 gain and pointed in the direction of the where the transmitter
is thought to be. With a slow sweeping motion and advancing
towards the transmitter the technician watches the meter or
signal lights for the greatest signal, the technician is then able to
identify the direction in which the greatest gain comes from.
While moving closer to the transmitter the technician will likely be
required to turn down the gain due to the proximity of the signal.
Move the receiver from side to side or back and forth with
receiver or external antenna (if used) pointing perpendicular to
the tool. When the receiver is perpendicular to and exactly in the
middle of the transmitter a null (sharp loss) in the signal strength
will be evident. In fact, at that precise position the receiver may
indicate that there is no signal.
