DDancer
Bronze Member
- Mar 25, 2014
- 2,339
- 2,002
- Detector(s) used
-
Current Equinox 600
Past Whites DFX Garret GTI 2500 and others
Prospecting Minelab GPZ 7000
Past SD 2100 GP 3000 (retired)
- Primary Interest:
- All Treasure Hunting
No worries OBN. Carl may have some input on your desire for depth. I'll chuck my two cents in though~
When one considers depth for a detector you'll pretty much always have to change the size of your detectors coil. Increased sensitivity and good ground balance are essential for what ever mode of operation your in but its the physical characteristics of the coil that drive depth.
One way to visualize this is to consider what I and Carl have said in this, and what you understand, : Detectors will only give a target response if the field of the detector interacts with the target strongly enough for the receiver circuits *this includes the RX portion of the coil* to create a target response and ; emissions from a radio source expand indefinitely from the transmitter.
The visualization is this : Consider the pattern a 4 inch bar magnet makes when you sprinkle iron shavings around it~ a circular oblong pattern. This pattern is similar to the output field of a transmitter *in only the most simple terms* now place a dime, a quarter and a half dollar in the center. These coins represent your coil and the magnetic field diagramed by the shavings your field. Your coil will only pick of a distortion of that field if its distorted far enough to interact with the edge of one of these coins. Move another magnet *your target* into that field and when the field distorts to the edge of the coin/coil you will have a response. A bigger magnet will distort the field at greater distance, a smaller one you will have to force in closer to distort the field so that your coins/coils will cover the area of distortion.
That's a very simplistic way to visualize how coils pick up targets and its an experiment you can do at home as well
The moral of the visualization is that your coins/coils will only really see what they can physically cover for the most part.
Your probably aware of it but there is a trade off as well when using larger coils for depth~ you'll tend to loose smaller targets. This is primarily due to the fact that because of the increased size of the RX portion of the coil electrical losses will occur and small targets wont be reactive enough to trigger a target response.
This attenuation, unfortunately, cant be avoided. The sensitivity control is what sets the level for target response but it generally can not be set to a level to fully compensate for the attenuation caused by larger coils without the detector becoming unsteady. Especially if there are other electrical interferences.
When one considers depth for a detector you'll pretty much always have to change the size of your detectors coil. Increased sensitivity and good ground balance are essential for what ever mode of operation your in but its the physical characteristics of the coil that drive depth.
One way to visualize this is to consider what I and Carl have said in this, and what you understand, : Detectors will only give a target response if the field of the detector interacts with the target strongly enough for the receiver circuits *this includes the RX portion of the coil* to create a target response and ; emissions from a radio source expand indefinitely from the transmitter.
The visualization is this : Consider the pattern a 4 inch bar magnet makes when you sprinkle iron shavings around it~ a circular oblong pattern. This pattern is similar to the output field of a transmitter *in only the most simple terms* now place a dime, a quarter and a half dollar in the center. These coins represent your coil and the magnetic field diagramed by the shavings your field. Your coil will only pick of a distortion of that field if its distorted far enough to interact with the edge of one of these coins. Move another magnet *your target* into that field and when the field distorts to the edge of the coin/coil you will have a response. A bigger magnet will distort the field at greater distance, a smaller one you will have to force in closer to distort the field so that your coins/coils will cover the area of distortion.
That's a very simplistic way to visualize how coils pick up targets and its an experiment you can do at home as well
The moral of the visualization is that your coins/coils will only really see what they can physically cover for the most part.Your probably aware of it but there is a trade off as well when using larger coils for depth~ you'll tend to loose smaller targets. This is primarily due to the fact that because of the increased size of the RX portion of the coil electrical losses will occur and small targets wont be reactive enough to trigger a target response.
This attenuation, unfortunately, cant be avoided. The sensitivity control is what sets the level for target response but it generally can not be set to a level to fully compensate for the attenuation caused by larger coils without the detector becoming unsteady. Especially if there are other electrical interferences.
