There is a good reason why the Explorer does not have problems with soil minerals. I have been thinking about how to cut through a lot of pages of technical explanation so here is a shot. The Explorer has a sequence of pulses that are long, short and medium. A specific number of pulses are a cycle. The cycles repeat as long as the detector is on.
The receiver coil is directly coupled to an amplifier that is directly coupled to demodulators. The inputs to the demodulators are controlled by gates that are turned ON and OFF at very specific points in time in reference to the transmitter pulses.
# 1. The demodulators are never ON when the TRANSMITTER IS ON.
# 2. The demodulators are turned ON after the TRANSMITTER PULSE has decreased to zero.
This will boil a lot of data, instantaneous and historical ground data down. The transmission frequency is between 1.5 kHz and 100 kHz. The speed is so fast that a target appears to be standing still in relationship to this frequency of operation. However, the electronics can measure instantaneous and historical data and predict future data.
Consider a single cycle or sequence of pulses. The ground matrix is primarily resistive in compared to a metal target. A ground signal only last for about 1us after the transmitter pulse. The demodulators are off during transmission and are gated ON at the end of the transmission pulse. The data fed to the demodulators is the 1us ground signal. The ground signal is a resistive conductive target that is predominantly resistive. ONLY after this 1us time elapses are the demodulators gated ON to detect target signals. By sampling the target signals and measuring the decay of the signal the ID of a metal is determined. A ferrous metal has a short delay due to the permeability, magnetics, of iron. Other targets have much shorter rates of decay. This decay could be compared to a ski slope in which the angle of the slope represents the inductance of a target as it decays through the resistance of the target.
@ All ground signal cannot be completely eliminated due to the fact that no electronics is perfect, ages with time, Q of coil changes as it is swept over the coil, etc. However, sensitivity is used to adjust for these nonlinear factors to eliminate the minute ground noise that escapes the digital filters.
** The Explorer does not have problems with soil minerals other than the extremely slight amount as indicated and can be eliminated. Semi-auto sensitivity or manual can be adjusted to eliminate soil mineral noise.
What we see posted as soil mineral nulls is really not correct. The nulls are caused from refined iron in the soil. Some nulls or positive hits will be noticed on hot and cold rocks. A hot or cold rock is a rock with a high concentrating of minerals in a rock. When we sweep the coil over the soil one measure of soil mineral is that they are slowly and constantly changing. Metal targets have an abrupt change. A hot or cold rock has an abrupt change so at time will look like a metal target. However, the detector has virtually no response to soil mineral that has anything to do with a null in the threshold.
The nulls we hear are due to metal being rejected based on where we have the discrimination set.
The receiver coil is directly coupled to an amplifier that is directly coupled to demodulators. The inputs to the demodulators are controlled by gates that are turned ON and OFF at very specific points in time in reference to the transmitter pulses.
# 1. The demodulators are never ON when the TRANSMITTER IS ON.
# 2. The demodulators are turned ON after the TRANSMITTER PULSE has decreased to zero.
This will boil a lot of data, instantaneous and historical ground data down. The transmission frequency is between 1.5 kHz and 100 kHz. The speed is so fast that a target appears to be standing still in relationship to this frequency of operation. However, the electronics can measure instantaneous and historical data and predict future data.
Consider a single cycle or sequence of pulses. The ground matrix is primarily resistive in compared to a metal target. A ground signal only last for about 1us after the transmitter pulse. The demodulators are off during transmission and are gated ON at the end of the transmission pulse. The data fed to the demodulators is the 1us ground signal. The ground signal is a resistive conductive target that is predominantly resistive. ONLY after this 1us time elapses are the demodulators gated ON to detect target signals. By sampling the target signals and measuring the decay of the signal the ID of a metal is determined. A ferrous metal has a short delay due to the permeability, magnetics, of iron. Other targets have much shorter rates of decay. This decay could be compared to a ski slope in which the angle of the slope represents the inductance of a target as it decays through the resistance of the target.
@ All ground signal cannot be completely eliminated due to the fact that no electronics is perfect, ages with time, Q of coil changes as it is swept over the coil, etc. However, sensitivity is used to adjust for these nonlinear factors to eliminate the minute ground noise that escapes the digital filters.
** The Explorer does not have problems with soil minerals other than the extremely slight amount as indicated and can be eliminated. Semi-auto sensitivity or manual can be adjusted to eliminate soil mineral noise.
What we see posted as soil mineral nulls is really not correct. The nulls are caused from refined iron in the soil. Some nulls or positive hits will be noticed on hot and cold rocks. A hot or cold rock is a rock with a high concentrating of minerals in a rock. When we sweep the coil over the soil one measure of soil mineral is that they are slowly and constantly changing. Metal targets have an abrupt change. A hot or cold rock has an abrupt change so at time will look like a metal target. However, the detector has virtually no response to soil mineral that has anything to do with a null in the threshold.
The nulls we hear are due to metal being rejected based on where we have the discrimination set.