Locating
Transmitter’s Signal Shape
It is important to understand some fundamental con- cepts about the transmitter’s electromagnetic signal and the way the receiver’s antennas read or receive this signal. The shape of the transmitter’s signal field is elliptical. This elliptically shaped field combined with the DigiTrak Receiver’s unique “X” antenna configura- tion results in locating the transmitter at three specific locations, not just the strongest/highest signal.
The transmitter’s electromagnetic field is made up of many “field signal lines.” As you locate, you are walking in this magnetic field and your receiver’s an- tennas are picking up signal from those field lines.
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Elliptical Shape of Transmitter Signal Field
Antenna Configuration
The DigiTrak Receiver has a total of three antennas. The single antenna near the bottom of the unit receives pitch, roll, battery, and temperature status from the transmitter. The “locating antennas” are located below the display windows and are in an “X” configuration. One of the antennas is referred to as the minus
each 45° to the surface below the DigiTrak Receiver. As described above, the more
Each antenna receives a different part of the field signal. This information is processed by the receiver to provide the operator with a measurement of the transmitter’s entire signal field strength— not just a portion, as with conventional cable locators.
Signal Reception
To understand how the antennas “read” these field lines, it is useful to imagine the field line as a stream of water and the antenna as a pipe. If a stream of water is aligned parallel with the pipe, then 100% of the water will flow through the pipe. If you turn the pipe 90° to the stream of water, no water will enter the pipe. The same principle is true for the field line and the antenna; when they are parallel to one another 100% of the field line will be read by the antenna, and when they are perpendicular to one another none (0%) of the signal will be read.
54 | DigiTrak® Mark III Operator’s Manual |
